Thursday, May 14, 2009

San Francisco Walking Tours - From History to Ghosts

While it's said that "nobody walks in L.A.," it's known that everyone walks in San Francisco. Having been a resident and frequent visitor to San Francisco, I can tell you that the very idea of walking in the City has always seemed odd to me. Let's face it; it's not the flattest town in which to walk. Yet, that's what everyone does. Walk, and huff and puff, and walk some more. There's just something about San Francisco that makes you want to step outside your hotel and walk. Perhaps it has something to do with the many different fascinating neighborhoods and buildings that compel people to slow down and take it all in.

If you're planning a vacation or holiday to San Francisco one of the best ways to actually experience the city is to take a walking tour. And, when it comes to walking tours, both free and fee-required, San Francisco has more than its share (it must have taken some from L.A.).

Free Walking Tours

First, let's begin with the free tours offered by San Francisco City Guides, a non-profit organization of more than 200 trained volunteers who lead free walking tours in San Francisco (donations, of course, are gladly accepted). If you visit their website, sfcityguides.org, you'll notice an interesting array of free walking tours offered every day of the week, tours like "1906 Earthquake and Fire," "Art Deco Marina," "Chinatown," "City Hall," "Downtown Deco," "Financial District" and "Gold Coast Architecture." A few of the more interesting walks include:

"Bawdy & Naughty"

This downtown two-block walk explores the arrival of "professional" women in San Francisco during the Gold Rush. And, no, we're not talking about women doctors or lawyers.

"Castro: Tales of the Village"

The Castro area in San Francisco is a predominately gay area of town. But, it wasn't always that way. This tour explores the early years of the Castro.

"Coit Tower Murals"

This tour takes visitors to Coit Tower on Telegraph Hill to view the Murals created by some of California's leading artists of the 30s depicting life in the Great Depression. The murals are definitely worth seeing, either as a tour group or on your own. San Francisco City Guides say their tour shows you some murals not shown to the general public, so I recommend you consider the tour for this San Francisco landmark.

"Ghost Walks"

Here are a couple fun walking tours. The "Ghost Walk at City Hall" and the "Ghost Walk at the Palace" are held in October only, and explore, what else, ghostly occurrences.

The tours typically begin in easy to identify and very public places and most of them even meet near access to public transportation in order to accommodate visitors coming from other areas of the city.

Fee-Required Tours:

While you do have plenty of opportunity for free walking tours, you might also consider some of the fee-required tours. One such fee-required tour is Hobnob Tours, a walking tour of Nob Hill, often times referred to as Snob Hill due to the number of wealthy people who live there. This two-hour tour costs $30 and takes you to an elegant ballroom where Tony Bennett belted out "I Left My Heart in San Francisco," through spectacular Grace Cathedral, through Huntington Park, with a cable car ride up Nob Hill. There is an optional breakfast, lunch or high tea at added cost. You can call for more information at 866-851-1123.

Another Fee-required tour is a tour of Chinatown which includes a visit to a fortune cookie factory and herbal pharmacy, as well as a hosted 10-course Dim Sum lunch at a Chinatown restaurant. The tour-only price is $28 for adults, $15 for children 6-17. With the added Dim Sum lunch the price is $40 for adults, $27 for children. You can call for reservations at 415-982-8839.

Whichever tour you decide to take you will probably leave you feeling satisfied, either with a greater insight to San Francisco, or with great Dim Sum.

Shari Hearn is a writer and creator of Top Vacation Spots, where you can learn about such things as Canary Island Holidays.
 

CCNP certification is getting a new look at the end of 2006. The BSCI and BCMSN exams are being updated, and the CIT and BCRAN exams are being retired. Let's take a look at what to expect from the new BSCI exam.

According to Cisco's exam blueprint - admittedly a very broad blueprint at this time - the major new topics are IP version 6 (IPv6) and multicasting. The addition of these two topics will make an already demanding Cisco certification exam that much tougher, but this is a great change for the exam and for the candidate. IPv6 is just going to become more and more prevalent in today's networks, and multicasting is as well.

Multicasting for the Cisco CCNP BSCI exam is going to go far beyond what you learned about it in your CCNA studies. For the new BSCI exam, you'll need to know the different methods of creating multicast groups as well as assigning members to them. This material was previously limited to CCIE-level books, and while I don't look for the questions to be as hard as the CCIE written exam, multicasting is not an easy topic and should not be taken lightly by the CCNP candidate in 2007.

One major CCNP exam topic that isn't going anywhere is BGP. The Border Gateway Protocol has been a big part of previous BSCI exams, and that looks to continue.

If you're pursuing your CCNP certification in 2007, be sure to monitor Cisco's website for additions to the CCNP blueprint. It's obvious that Cisco has raised the bar for CCNP certification, and earning this important Cisco certification will in turn raise your market value and networking knowledge like never before. Watch for future tutorials examining the other three new CCNP exams!

Chris Bryant, CCIE #12933, is the owner of The Bryant Advantage, home of over 100 free certification exam tutorials, including Cisco CCNA certification test prep articles. His exclusive Cisco CCNA study guide and Cisco CCNA training is also available!

Visit his blog and sign up for Cisco Certification Central, a daily newsletter packed with CCNA, Network+, Security+, A+, and CCNP certification exam practice questions! A free 7-part course, ?How To Pass The CCNA?, is also available, and you can attend an in-person or online CCNA boot camp with The Bryant Advantage!

 

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Friday, May 9, 2008

San Francisco Gets Serious About Arts Education

The Arts Education Master Plan

September 28 was the beginning of a new era for arts education in San Francisco schools. The San Francisco Unified School district and the City are partnering on a historic effort to bring back the arts for all students. The Arts Education Master Plan will revitalize the education of San Francisco?s young citizens by capturing the diverse cultural and artistic energy of a city that is internationally renowned for its love of the arts.

At 10:30 a.m. at the San Francisco Performing Arts Library and Museum, Mayor Gavin Newsom, SFUSD?s Interim Superintendent Gwen Chan, and SF Arts Commission President P.J. Johnston joined members of the Board of Supervisors and SFUSD Board of Education, arts providers from across the city and students from Lowell High School, Claire Lilienthal and George Washington Carver Academic Elementary Schools in celebration of the Arts Education Master Plan.

"This master plan is a living document that exemplifies the partnership between the City and the school district on arts education," said Mayor Newsom. "San Francisco's efforts are unprecedented - and over the next few months, we will witness 'order of magnitude' changes in the arts education that children receive," continued the Mayor.

The Arts Education Master Plan is San Francisco Unified School District's blueprint for integrating the arts into each student's daily curriculum. The Plan calls for a sequential, comprehensive arts education program that reflects the high quality of San Francisco's artistic landscape in the areas of dance, drama, music, visual arts and literary arts.
The guiding principle of this plan is that all students deserve both access to and equity in arts education and each school community, no matter the neighborhood or academic emphasis, will be called upon to embrace the notion that every student must be provided with the arts as an integral part of the academic day.

Interim Superintendent Gwen Chan said ?In San Francisco, we are committed to providing every student with a well-rounded education. For too many years, some students have not had opportunities to develop artistic literacy. Every school and every student will benefit from this plan.?

Community Involvement

The Master Plan reflects the views of more than 1,500 students, parents, teachers, administrators, arts providers, and civic and business leaders. Proposition H approved by San Francisco voters in 2004, became the catalyst, making the Arts Education Master Plan, completed in August 2006, a funded mandate. The extensive increase in arts education spending, programming, support and resources that the Plan recommends will be funded largely by Prop H funds. Additional funding, such as the new State funding for the arts, will be aligned to the Arts Education Master Plan.

The new plan will hopefully keep San Francisco school students in touch with the vibrant artistic community around them and help them to take advantage of the many enriching opportunities for art in the classroom and beyond. San Francisco schools are ready to implement the new curriculum program at all levels to ensure a consistent and fulfilling learning experience for all students. Students, parents, and teachers at San Francisco schools are confident that the Arts Education Master Plan will mark their community as one committed to continued arts education.



Stacy Andell is a staff writer for Schools K-12, providing free, in-depth reports on all U.S. public and private K-12 schools. For more information on San Francisco schools visit http://www.schoolsk-12.com/california/san-francisco/index.html

 

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Friday, March 14, 2008

Cisco CCNA Certification Exam Tutorial: Keep Your Most Important Appointment

Imagine this. You have an appointment with a client to work on a server or router install. A few minutes before you're scheduled to be there, you decide there's something really good on TV you'd like to watch. Or you decide to go to the gym, or play a game, or do anything else except go see the client. Even if you weren't going to get fired for not showing up, it's certainly unfair to the client. You've got a professional obligation, and you should be there on time.

Now, what's this got to do with you becoming a CCNA or CCNP? Plenty. Because when it comes to your study time, you're the client. You owe it to yourself to show up. You would never blow off an appointment to meet a client to get some important work done.

First, though, you have to make that appointment with yourself! Schedule your CCNA / CCNP study time, and keep that appointment as you would with a client. Turn off the TV, your cell, your iPod, and everything else electronic that you carry around. Believe it or not, the world can survive with being in contact with you for an hour or so! You might even like it!

Getting certified isn't about how many hours, days, or weeks you spend studying. It's about how much quality time you put in. Be honest with yourself and realize that you're better off with 45 minutes of uninterrupted study as you would be with three hours of constantly interrupted study.

Don't blow off an appointment to yourself, either. Schedule the time, be there on time, get your study done, and you're one step closer to your CCNA and CCNP!

Chris Bryant, CCIE #12933, is the owner of The Bryant Advantage (http://www.thebryantadvantage.com), home of free CCNA and CCNP tutorials! For my FREE "How To Pass The CCNA" or "CCNP" ebook, visit the website and download your copies. Get your CCNA study guide from The Bryant Advantage!

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Friday, February 1, 2008

Cisco CCNP Certification/BCMSN Exam Tutorial: Uplinkfast

You remember from your CCNA studies that when a port goes through the transition from blocking to forwarding, you're looking at a 50-second delay before that port can actually begin forwarding frames. Configuring a port with PortFast is one way to get around that, but again, you can only use it when a single host device is found off the port. What if the device connected to a port is another switch?

A switch can be connected to two other switches, giving that local switch a redundant path to the root bridge, and that's great - we always want a backup plan! However, STP will only allow one path to be available, but if the available path to the root switch goes down, there will be a 50-second delay due to the STP timers MaxAge and ForwardDelay before the currently blocked path will be available.

The delay is there to prevent switching loops, and we can't use PortFast to shorten the delay since these are switches, not host devices. What we can use is Uplinkfast.

The ports that SW3 could potentially use to reach the root switch are collectively referred to as an uplink group. The uplink group includes the ports in forwarding and blocking mode. If the forwarding port in the uplink group sees that the link has gone down, another port in the uplink group will be transitioned from blocking to forwarding immediately. Uplinkfast is pretty much PortFast for wiring closets. (Cisco recommends that Uplinkfast not be used on switches in the distribution and core layers.)

Some additional details regarding Uplinkfast:

The actual transition from blocking to forwarding mode takes about three seconds.

Uplinkfast cannot be configured on a root switch.

Uplinkfast is configured globally. You can't run Uplinkfast on some ports or on a per-VLAN basis - it's all or nothing.

The original root port will become the root port again when it detects that its link to the root switch has come back up. This does not take place immediately. The switch uses the following formula to determine how long to wait before transitioning back to the forwarding state:

( 2 x FwdDelay) + 5 seconds

Uplinkfast will take immediate action to ensure that the switch upon which it is configured cannot become the root switch. First, the switch priority will be set to 49,152, which means that if all other switches are still at their default priority, they'd all have to go down before this switch can possibly become the root switch. Additionally, the STP Port Cost will be increased by 3000, making it highly unlikely that this switch will be used to reach the root switch by any downstream switches.

And you just know there's got to be at least one option with this command, right? Let's run IOS Help and see.

SW2(config)#spanning-tree uplinkfast ?

max-update-rate Rate at which station address updates are sent

When there is a direct link failure, dummy multicast frames are sent to the MAC destination 0100.0ccd.cdcd. The max-update-rate value determines how many of these frames will be sent in a 100-millisecond time period.

Mastering the details of UplinkFast, BackboneFast, BPDU Guard, and Loop Guard are vital to your success on the CCNP exams, and one or more of these features are in use on almost every network in the world. Learn these features for success in both the exam room and the real world!
Chris Bryant, CCIE #12933, is the owner of The Bryant Advantage (http://www.thebryantadvantage.com). For a copy of his FREE "How To Pass The CCNA" or "CCNP" ebook, visit the website and download your copies! Daily exam questions and tutorials now available through RSS feed!

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Thursday, January 24, 2008

Cisco CCNP / BSCI Exam Tutorial: Filtering BGP Updates With Prefix Lists

A major part of your BSCI and CCNP exam success is mastering BGP, and that includes filtering BGP routing updates. In this tutorial, we'll take a look at how to filter BGP updates with prefix lists.

R4 is advertising three networks via BGP. The downstream router R3 sees these routes and places them into its BGP table as shown below. R3 has two downstream BGP peers, R1 and R2, and is advertising itself as the next-hop IP address for all BGP routes sent to those two routers.

R4(config)#router bgp 4

R4(config-router)#network 21.0.0.0 mask 255.0.0.0

R4(config-router)#network 22.0.0.0 mask 255.0.0.0

R4(config-router)#network 23.0.0.0 mask 255.0.0.0

R3#show ip bgp

BGP table version is 4, local router ID is 3.3.3.3

Status codes: s suppressed, d damped, h history, * valid, > best, i - Internal

Origin codes: i - IGP, e - EGP, ? - incomplete

Network Next Hop Metric LocPrf Weight Path

*> 21.0.0.0 10.2.2.4 0 0 4 I

*> 22.0.0.0 10.2.2.4 0 0 4 I

*> 23.0.0.0 10.2.2.4 0 0 4 I

R3(config)#router bgp 123

R3(config-router)#neighbor 172.12.123.1 next-hop-self

R3(config-router)#neighbor 172.12.123.2 next-hop-self

In turn, both R1 and R2 have these three routes in their respective BGP tables.

R2#show ip bgp

BGP table version is 4, local router ID is 2.2.2.2

Status codes: s suppressed, d damped, h history, * valid, > best, i - Internal

Origin codes: i - IGP, e - EGP, ? - incomplete

Network Next Hop Metric LocPrf Weight Path

*>i21.0.0.0 172.12.123.3 0 100 0 4 I

*>i22.0.0.0 172.12.123.3 0 100 0 4 I

*>i23.0.0.0 172.12.123.3 0 100 0 4 I

R1#show ip bgp

BGP table version is 4, local router ID is 19.1.1.1

Status codes: s suppressed, d damped, h history, * valid, > best, i - Internal

Origin codes: i - IGP, e - EGP, ? - incomplete

Network Next Hop Metric LocPrf Weight Path

*>i21.0.0.0 172.12.123.3 0 100 0 4 I

*>i22.0.0.0 172.12.123.3 0 100 0 4 I

*>i23.0.0.0 172.12.123.3 0 100 0 4 I

If we wanted R3 to receive all three of these routes from R4 but not advertise all of them to R2 and R1, we've got a couple of options on how to block these routes. Cisco's recommendation is the use of prefix-lists, and once you get used to the syntax (which you should do before taking and passing the BSCI), you'll see they are actually easier to use than access-lists.

In this case, we're going to configure R3 to send only the route to 21.0.0.0 to R1 and 23.0.0.0 to R2. However, we do want these two routers to get any future routes that R4 advertises into BGP.

Since R1 and R2 will learn about these routes from an iBGP neighbor, they will not advertise the routes to each other.

On R3, we'll write a prefix-list that denies 22.0.0.0/8 and 23.0.0.0/8, but permits all other routes. After applying the prefix list as shown, R1 sees only the 21.0.0.0 /8 route.

R3(config)#ip prefix-list FILTER_R1 deny 22.0.0.0/8

R3(config)#ip prefix-list FILTER_R1 deny 23.0.0.0/8

R3(config)#ip prefix-list FILTER_R1 permit 0.0.0.0/0 le 32

R3(config)#router bgp 123

R3(config-router)#neighbor 172.12.123.1 prefix-list FILTER_R1 out

R3#clear ip bgp * soft

R1#show ip bgp

BGP table version is 6, local router ID is 19.1.1.1

Status codes: s suppressed, d damped, h history, * valid, > best, i - Internal

Origin codes: i - IGP, e - EGP, ? - incomplete

Network Next Hop Metric LocPrf Weight Path

*>i21.0.0.0 172.12.123.3 0 100 0 4 I

The paths to 22.0.0.0/8 and 23.0.0.0/8 have been successfully filtered.

We'll do the same for R2, except the route not being expressly blocked is 23.0.0.0/8. The line "ip prefix-list permit 0.0.0.0/0 le 32" is the prefix list equivalent of a "permit any" statement in an ACL.

R3(config)#ip prefix-list FILTER_R2 deny 21.0.0.0/8

R3(config)#ip prefix-list FILTER_R2 deny 22.0.0.0/8

R3(config)#ip prefix-list FILTER_R2 permit 0.0.0.0/0 le 32

R3(config)#router bgp 123

R3(config-router)#neighbor 172.12.123.2 prefix-list FILTER_R2 out

R3#clear ip bgp * soft

R2#show ip bgp

BGP table version is 6, local router ID is 2.2.2.2

Status codes: s suppressed, d damped, h history, * valid, > best, i - Internal

Origin codes: i - IGP, e - EGP, ? - incomplete

Network Next Hop Metric LocPrf Weight Path

*>i23.0.0.0 172.12.123.3 0 100 0 4 I

The paths to 21.0.0.0/8 and 22.0.0.0/8 have been successfully filtered.

To see the prefix lists configured on a route as well as the order of the statements in each list, run show ip prefix-list.

R3#show ip prefix-list

ip prefix-list FILTER_R1: 3 entries

seq 5 deny 22.0.0.0/8

seq 10 deny 23.0.0.0/8

seq 15 permit 0.0.0.0/0 le 32

ip prefix-list FILTER_R2: 3 entries

seq 5 deny 21.0.0.0/8

seq 10 deny 22.0.0.0/8

seq 15 permit 0.0.0.0/0 le 32

Get some hands-on practice with prefix lists and you'll quickly master them. Prefix lists are an important part of working with BGP in the exam room and production networks, so it's vital that you are comfortable working with them.

Chris Bryant, CCIE #12933, is the owner of The Bryant Advantage , home of free CCNA and CCNP tutorials! Pass the CCNA exam with Chris Bryant!

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Cisco CCNA Exam Tutorial: Cisco Discovery Protocol (CDP)

The Cisco Discovery Protocol (CDP) sure looks simple enough, but there are quite a few details to know for success on the CCNA exam. In your CCNP studies, you'll be introduced to additional uses for CDP, but for now it's enough to know that CDP is designed to give you information regarding directly connected Cisco routers and switches.

CDP runs by default between all directly connected Cisco devices. CDP is also a Cisco-proprietary protocol - if the directly connected device is not a Cisco device, you won't see the information you wanted.

The basic CDP command to display information about the directly connected neighbor is "show cdp neighbor".

R2#show cdp neighbor

Capability Codes: R - Router, T - Trans Bridge, B - Source Route Bridge

S - Switch, H - Host, I - IGMP, r - Repeater

Device ID Local Intrfce Holdtme Capability Platform Port ID

R1 BRI0 167 R 2521 Dialer1

This command is particularly helpful when troubleshooting Cisco switches. There's no need to trace wiring in a rack of Cisco devices to see what routers are connected to a Cisco switch when show cdp neighbor can be used. In the above output, you can see the remote device's hostname, what interface on the remote device is connected to the local device, the capability of the remote device, the remote device's hardware platform, and the local interface that is connected to the remote device.

CDP can be disabled at both the global and interface level. To disable CDP at the interface level, run no cdp enable on the interface, and cdp enable to turn it back on.

cdp timer defines how often CDP packets are transmitted, and cdp holdtime defines how long a device will hold a received packet.

To turn CDP off for the entire router, run no cdp run. To view the current global status of CDP, run show cdp.

R2#show cdp

Global CDP information:

Sending CDP packets every 60 seconds

Sending a holdtime value of 180 seconds

CDP is running by default.

R2#conf t

R2(config)#cdp timer 45

R2(config)#cdp holdtime 100

The CDP timers are changed.

R2#show cdp

Global CDP information:

Sending CDP packets every 45 seconds

Sending a holdtime value of 100 seconds

The CDP values have been successfully changed. "show cdp interface" will give the timer information for each interface on the router.

R2#conf t

R2(config)#interface bri0

R2(config-if)#no cdp enable

CDP is disabled on the BRI interface. This does NOT have to be done to keep the line from dialing.

R2#conf t

R2(config)#no cdp run

CDP is disabled globally.

R2#show cdp

% CDP is not enabled

CDP has been successfully disabled.

Show cdp neighbor gives you a great deal of information, but what if you need the neighbor's IP address? Just run show cdp neighbor detail. You will get even more information about that directly connected neighbor, including its IP address.

SW2#show cdp neighbor detail

 

Device ID: R4

Entry address(es):

IP address: 172.12.23.4

Platform: cisco 2520, Capabilities: Router

Interface: FastEthernet0/4, Port ID (outgoing port): Ethernet0

Holdtime : 158 sec

The details of CDP are important to you on the job and in the CCNA exam room. When you find yourself negotiating a badly documented network, you can use CDP to "walk" through the network and create a network map for your client as well. Sometimes the simplest protocols are the most helpful!

Chris Bryant, CCIE #12933, is the owner of The Bryant Advantage , home of free CCNA and CCNP tutorials! Pass the CCNA exam with Chris Bryant!

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Sunday, January 13, 2008

Luxurious Lifestyle At The San Francisco Bay Area

The San Francisco Bay Area, popularly known as the 'Bay Area' to local residents, is a diverse and thriving metropolitan region that encompasses San Francisco Bay in the northern part of California. San Francisco, North Bay, East Bay, South Bay, Peninsula and Santa Cruz make up the Bay Area regions. They are divided into nine counties: San Francisco, San Benito, San Mateo, Santa Clara, Santa Cruz, Alameda, Napa, Solano and Sonoma.

Although San Francisco City is identified as the cultural and traditional center of the Bay Area, it is not the largest or most populated city within the area. Historically, the Bay Area traces its roots from Spanish explorers who first set foot in the region and founded a Catholic church in 1776.

Bay Area is distributed over a population of nearly seven million residents (as of the latest count in 2006). People are scattered over a number of suburban and urban centers, hence, the general area name. Its generic name is derived from the various regional natures of the area, with no specific reference to a city.

Studies place the population of San Francisco Bay Area among the best in the country for overall education placement, competing with Washington D.C. and Boston. East Bay is known for being the home of famous seminaries and universities, namely Berkeley or the University of California and Stanford University.

Weather is generally agreeable but unpredictable, as bodies of water fence in the land area. Spring casts mild and cloudless days, summer is cool and overcast, and fall weather is warm, hot and sunny, with mild and clear nights, while winter brings in the most humid rainy days, alternating with clear and sunny skies.

The diverse geography is broken up into prime residential and industrial spaces, covering villages, towns and cities, parks in the national, state and regional levels, as well as airports and military bases. All these are connected by a modern and efficient transport system composed mostly of trains (commuter rail and railroads), highways and roads.

Considered as one of the most affluent regions in America, the San Francisco Bay Area boasts having the most median income per household, across the nation. Six out of the 10 best Californian areas that have the most income per capita (Belvedere, Diablo, Atherton, Woodside and Portal Valley) are all in the Bay Area. The popular Alameda, Contra Costa, Marin, San Francisco, San Mateo and Santa Clara counties in Bay Area are also part of the top 100 income per capita counties in the States. As a result, the Bay Area real estate appreciated to the level of the 'most expensive zip code' league. In 2005, Forbes Magazine listed Atherton, Diablo, Ross, Nicasio, Los Altos, Tiburon, Los Gatos, Portal Valley and San Francisco as one of the top 50 most expensive places to live in.
Visit http://www.johnhomesonline.com for more information about California travel.

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Sunday, January 6, 2008

Cisco CCNA Exam Tutorial: Password Recovery Procedures

It might happen on your CCNA exam, it might happen on your production network - but sooner or later, you're going to have to perform password recovery on a Cisco router or switch. This involves manipulating the router's configuration register, and that is enough to make some CCNA candidates and network administrators really nervous!

It's true that setting the configuration register to the wrong value can damage the router, but if you do the proper research before starting the password recovery process, you'll be fine.

Despite what some books say, there is no "one size fits all" approach to Cisco password recovery. What works on a 2500 router may not work on other routers and switches. There is a great master Cisco document out on the Web that you should bookmark today. Just put "cisco password recovery" in your favorite search engine and you should find it quickly.

The following procedure describes the process in recovering from a lost password on a Cisco 2500 router. As always, don't practice this at home. It is a good idea to get some practice with this technique in your CCNA / CCNP home lab, though!

The password recovery method examined here is for 2500 routers.

An engineer who finds themselves locked out of a router can view and change the password by changing the configuration register.

The router must first be rebooted and a "break" performed within the first 60 seconds of the boot process. This break sequence can also vary depending on what program is used to access the router, but is the usual key combination.

The router will now be in ROM Monitor mode. From the rom monitor prompt, change the default configuration register of 0x2102 to 0x2142 with the o/r 0x2142 command. Reload the router with the letter i. (As you can see, ROM Monitor mode is a lot different than working with the IOS!)

This particular config register setting will cause the router to ignore the contents of NVRAM. Your startup configuration is still there, but it will be ignored on reload.

When the router reloads, you'll be prompted to enter Setup mode. Answer "N", and type enable at the router> prompt.

Be careful here. Type configure memory or copy start run. Do NOT type write memory or copy run start!

Enter the command show running-config. You'll see the passwords in either their encrypted or unencrypted format.

Type config t, then use the appropriate command to set a new enable secret or enable password.

Don't forget to change the configuration register setting back to the original value! The command config-register 0x2102 will do the job. Save this change with write memory or copy run start, and then run reload one more time to restart the router.

This process sounds hard, but it's really not. You just have to be careful, particularly when you're copying the startup config over the running config. You don't want to get that backwards! So take your time, check the online Cisco documentation before starting, get some practice with this procedure with lab equipment, and you'll be ready for success on the CCNA exam and in your production network!

Chris Bryant, CCIE #12933, is the owner of The Bryant Advantage (http://www.thebryantadvantage.com), home of free CCNA and CCNP tutorials! For my FREE "How To Pass The CCNA" or "CCNP" ebook, visit the website and download your copies. Pass your CCNA exam with The Bryant Advantage!

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Thursday, January 3, 2008

Cisco CCNA Exam Tutorial: How To Spend Your Study Time

To pass the CCNA exam, you've got to create a study plan. Part of that plan is scheduling your study time, and making that study time count.

You've scheduled your exam you've created a document to track your study time you've planned exactly when you're going to study. Now the plan must be carried out, without exception.

What exceptions do I mean? Cell phones. Televisions. IPods. Significant others. The list can go on and on.

It's one thing to have a plan, and an important thing now you've got to make sure you carry it out to its fullest potential. That's easy to say until you're studying and a friend calls, or you remember that TV show you wanted to watch is on tonight, or you start surfing the Web for Cisco information and end up playing a game.

You MUST make these small sacrifices in order to achieve your main goal, the CCNA. Any worthwhile accomplishment requires some small sacrifice.

TV will be there when you're done studying. Your significant other will be there when you're done studying. And believe it or not, people once existed without cell phones! Turn the phone off. Turn your instant messenger service off. Turn your text pager off. Despite what we think, the world can do without communicating with us for 90 minutes. Remember, it's better to have 90 minutes of great study than 180 minutes of constantly interrupted study. Studies show that while a single phone call causes an 11-minute interruption on average, it takes well over 20 minutes to get back to what you were doing with the proper mental focus. This is true at the office and at your home!

How To Spend Your Study Time CCNA candidates generally spend their time split between book study, practice exams, and lab time on real Cisco equipment. The best study is done by a combination of these, not by overly relying on one. Let's take a look at each method.

Book study - I've never understood why some people (usually the trolls we were talking about earlier) talk about book study like it's a bad thing. "You can't learn about technology from books." What a load of manure. You have to learn the theory before you can understand how a router or switch operates. The best way to learn the theory is to read a good book.

At the CCNA level, you doubtless know that you have dozens of choices when it comes to books. Some of the better-known books really do gloss over some important topics, such as binary math and subnetting. Make sure to pick a book or books that go beyond just explaining the theory and that give you a lot of explanation of router configs and real-world examples as well.

Practice Exams: Practice exams are good in moderation, but don't use them as your main focus of study. Occasionally, I'm asked for study tips by candidates who have taken the exam a few times and not passed yet. I ask them what they're doing to prepare, and they give a list of companies they bought practice exams from. (You see a lot of this on Internet forums as well.)

Don't fall into this trap. Practice exams are fine if used as a readiness check, but some candidates just take them over and over again, which renders them basically useless.

On top of that, some of them cost hundreds of dollars. That's money you'd be much better off spending on Cisco equipment to practice on.

Again, I'm not against practice exams as a supplement to your studies. Just don't make them the main focus of your study. Taking practice exams over and over and hoping the exam will be just like the practice exam is a recipe for disaster. As I tell my students, when you're in front of a rack of routers and switches during a job interview (or at 2AM when you've been called in to fix a problem), the correct answer is not "D". You've got to know what to do.

And how do you learn these skills? Funny you should ask.... Lab Time On Real Cisco Equipment. Again, speaking from experience: This is the most important part of getting your CCNA, succeeding on the job, and going on to get your CCNP.

Getting hands-on experience is critical to developing your networking skills, especially your troubleshooting skills. Although simulators are better than they used to be, they're still not Cisco routers, and they never will be.

You do your best learning not only when you're configuring your routers, but when you screw something up.

That's so important, I want to repeat it - loudly: You do your best learning when you screw something up. Why? Because then you have to fix it that's how you develop your troubleshooting skills. You can read about all the debug and show commands in the world, but you don't really understand how they work until you're figuring out why your Frame Relay connection isn't working, or your RIP configuration isn't working.

This is true at every level of the Cisco Learning Pyramid. I can show you the show ip protocols output or what you get when you run debug ip rip, and you might remember it for a little while. But when you use it to troubleshoot a lab configuration, you WILL remember it.

Putting your own practice lab together will also help get you over what I call "simulator question anxiety". If you spend any time on CCNA Internet forums, you'll see discussion after discussion about these exam questions. To a certain point, this discussion is justified. The simulator questions carry more weight on your exam than any other question while you can earn partial credit on them, you've got to get them right or you will most likely fail the exam.

There's no reason to be anxious about them if you're prepared. You don't want to be the person who walks into the testing room that's scared to have to create a VLAN or an access list you want to be the person who walks into the testing room confident of their ability to perform any CCNA task. The best way to be that confident is to know you've done it - on real Cisco equipment.

There are several vendors that sell routers and switches on ebay most of them sell CCNA and CCNP kits that include all the cables and transceivers that you'll need as well. (And how is a simulator going to help you learn about cables and transceivers?) Keep in mind that you can always sell the equipment after you're done with the CCNA, or you can add a little equipment to it to go after your CCNP.

Whichever of these methods you use (and I hope you'll use all of them), make sure to keep them in balance with each other. Don't depend too much on just one.

On the topic of learning how to troubleshoot... as you run labs on your Cisco equipment, you'll run into questions or problems that you don't know the answer to yet. Get used to using Google (or your favorite search engine) to find the answer to these problems - but try to figure it our yourself first!

There's nothing wrong with asking questions of someone else if you're not able to find the answer yourself. Trying to find the answer yourself is another important troubleshooting skill you need to start developing today. Don't be one of these people who posts a simple question on a forum without trying to find the answer on your own. Besides, you get more satisfaction and build more confidence when you determine the answer yourself.

Chris Bryant, CCIE #12933, is the owner of The Bryant Advantage (http://www.thebryantadvantage.com), home of free CCNA and CCNP tutorials! For my FREE "How To Pass The CCNA" or "CCNP" ebook, visit the website and download your copies. Pass your CCNA exam with The Bryant Advantage!

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Thursday, December 27, 2007

Cisco CCNP Exam Tutorial: Defining Collision Domains

CCNA exam success depends on mastering the fundamentals, and two important fundamentals are knowing exactly what the terms "collision domain" and "broadcast domain" mean. In this free Cisco tutorial, we'll take a look at the term "collision domain" and how a collision domain is defined.

A collision domain is an area in which a collision can occur. Fair enough, but what "collision" are we talking about here? We're talking about collisions that occur on CSMA/CD segments, or Carrier Sense Multiple Access with Collision Detection. If two hosts on an Ethernet segment transmit data at exactly the same time, the data from the two hosts will collide on the shared segment. CSMA/CD exists to lessen the chances of this happening, but collisions can still occur. To lessen the chances of collisions occurring, we may decide to create multiple, smaller collision domains.

Let's say we have four hosts on a single Ethernet segment. The entire segment is a collision domain; any data sent by one of the hosts can collide with data sent by any of the other hosts. We have one collision domain containing four devices.

To create smaller collision domains, we'll need to introduce some type of networking device into this example. Hubs and repeaters have their place as far as extending the reach of a network segment and cutting down on attenuation, but these OSI Layer One devices do nothing to define collision domains. We could connect each host into a separate port on a hub (a hub is basically a multiport repeater) and we'd still have one single collision domain with four hosts in it.

The most common and most effective way to create multiple collision domains is to use a switch. If we connect each of these four hosts to their own separate switch port, we would now have four separate collision domains, each with one host; each switch port actually acts as a single collision domain, making collisions between these four hosts impossible.

Passing the CCNA is all about knowing the details of how things work, and knowing CSMA/CD theory and how to define collision domains is one of the many details you've got to master. In the next part of this CCNA tutorial, we'll take a look at broadcast domains, and how defining broadcast domains in the right places can dramatically cut down on unnecessary traffic on your network.

Chris Bryant, CCIE #12933, is the owner of The Bryant Advantage (http://www.thebryantadvantage.com ), home of free CCNA and CCNP tutorials, and The Ultimate CCNA and CCNP Study Packages. For a copy of his FREE "How To Pass The CCNA" or "CCNP" ebook, visit the website and download your copies!

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Sunday, November 25, 2007

Cisco / MCSE Exam Study: Creating A Road Map To Success

Planning for success on the CCNA, CCNP, and other Cisco exams is much like taking a trip in your car. You've got to plan ahead, accept the occasional detour, and just keep on going until you get there. But what do you do before you get started?

Create a road map - for success.

If you were driving from one side of the country to another, you certainly wouldn't just get in your car and start driving, would you? No. You would plan the trip out ahead of time. What would happen if you just got in the car and started driving in the hope that you would someday arrive at your final destination? You would never get there, and you'd spend a lot of time wandering aimlessly.

Don't spend your study time and slow your progress by studying for a Cisco exam without planning the trip. Schedule your study time as you would an appointment with a client, and keep that appointment. Make sure that your study time is quality study - turn your TV, iPod, and cell off. If you hit a bump in the road and don't get your certification the first time you take the exam, regroup and create another plan. Study until you get to the point that on exam day, you know that you are already a CCNA or CCNP and you're just there at the testing center to make it official.

The journey to success is not a straight line. When you look at a chart that shows a company's financial progress, the line never goes straight up. there are some ups and downs, but the overall result is success. The path to your eventual career and certification exam success may not be a direct one, but the important part is to get started - and to get any journey started, you've got to create a road map for a successful arrival at your destination.

Chris Bryant, CCIE #12933, is the owner of The Bryant Advantage (http://www.thebryantadvantage.com), home of free CCNP and CCNA tutorials! For my FREE "How To Pass The CCNA" or "CCNP" ebook, visit the website and download your copies. Pass your CCNP exam with The Bryant Advantage!

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Monday, November 12, 2007

How To Become A Cisco VPN Specialist

 

There's quite an emphasis on security in today's networks, and that's reflected in Cisco's certification tracks. Cisco offers a CCIE Security track and the Cisco Certified Security Professional (CCSP) intermediate-level certification, but there is no real equivalent to the CCNA on the security side. Instead, Cisco offers several different Security Associate certifications.

The good news is that you've got a lot of security specializations from which to choose; the bad news is that you've got a lot of choices! In choosing a specialization, take some time to choose a certification that will be of practical use to you in your current position or in your "dream job".

One of the more popular Security Associate certifications is the Cisco VPN Specialist certification. This two-exam track consists of a Securing Cisco Network Devices (SND, 642-551) exam and a Cisco Secure Virtual Private Networks (CSVPN, 642-511) exam. To earn the Cisco VPN Specialist exam, you must hold a valid CCNA certification.

What should you expect on these exams? On the SND exam, expect to be grilled on basic security features on both switches and routers, as well as VPN 3000 concentrators, PIXes, and IDS/IPS Sensors. You'll need to be ready to configure and troubleshoot basic AAA configurations, access-lists, syslog, AutoSecure, and much more. You should also be solid with IPSec.

IPSec will also be part of your CSVPN exam. As you'd expect, you'll also be expected to be quite good with the VPN 3000 Concentrator series, including browser configuration, creating users and group, the Windows VPN Software Client, and more.

This is a demanding certification that is an excellent addition to your resume and your skill set. For the latest on this and other Cisco certifications, you should regularly visit the Learning & Events section of Cisco's website. As a Cisco certification candidate, it's your responsibility to stay current of any additions and changes to Cisco's certification paths - and it's good for your career!

Chris Bryant, CCIE #12933, is the owner of The Bryant Advantage , home of free CCNA and CCNP tutorials! Pass Pass the CCNA exam with Chris Bryant!

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Sunday, November 11, 2007

Cisco CCNA / CCNP Exam Tutorial: Five Debugs You Must Know


To pass the BSCI exam and move one step closer to CCNP certification success, you've got to know how and when to use debug commands to troubleshoot and verify network operations. While you should never practice debug commands on a production network, it's important to get some hands-on experience with them and not rely on "router simulators" and books to learn about them.

When it comes to RIP, "debug ip rip" is the primary debug to use. This debug will show you the contents of the routing update packets, and is vital in diagnosing RIP version mismatches and routing update authentication issues.

You know how to use the variance command to configure unequal-cost load-sharing with IGRP, but IGRP has no topology table that will give you the feasible successor metrics you need. With IGRP, you need to use the "debug ip igrp transactions" command to get these vital metrics.

Several factors are considered by OSPF-enabled routers when it comes to forming adjacencies, including hello and dead timer settings. If an adjacency doesn't form when you think it should, run "debug ip ospf adj". The reason the adjacency isn't forming is usually seen quickly with this command's output.

Let's not ignore Layer Two! If frame relay mappings are not forming according to your configuration, run "debug frame lmi". This debug will allow you to quickly diagnose and correct any LMI mismatches.

When it comes to PPP, it can be very frustrating to try to spot a problem with a password or username. Instead of staring at the configuration for 10 minutes, run "debug ppp negotiation" and send a ping over the link. This command will help you spot the router with the misconfigured username or password, not to mention saving you a lot of time!

Effectively using debugs during your CCNA and CCNP exam study will help you truly understand what's going on "behind the command" - and it will really come in handy on that day when your production network just isn't doing what you (think) you told it to do!

Chris Bryant, CCIE #12933, is the owner of The Bryant Advantage , home of free CCNA and CCNP tutorials! Pass the CCNA exam with Chris Bryant!

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Wednesday, October 31, 2007

2006 San Francisco Giants Preview

2005 Overview:

Without all star Barry Bonds in their lineup the 2005 San Francisco Giants struggled to score runs and find an identity. Newcomer Moises Alou (.321 19 63) didn't quite match his 2004 numbers with Chicago when he hit 39 homers and drove in 106 runs but his bat proved a reliable addition. Joining Alou in the 2005 lineup were Mike Matheny (.242 13 59), Pedro Feliz (.250 20 81) and Ray Durham (.290 12 62) with rookie 1st baseman Lance Niekro (.252 12 46) providing the majority of offense.

Giant pitching in 2005 was led by Jason Schmidt (12 7 4.40) who fell from his 18 win season in 2004. Joining Schmidt for the bulk of the pitching duties where Noah Lowry (13-13 3.78), Brett Tomko (8-15 4.48) and newcomer Brad Hennessey (5-8 4.64). The bullpen remained stable with Tyler Walker (6-4 4.23 23 saves) and closer Armando Benitez (2-3 4.50 19 saves) combining to save a total of 42 games between the two of them.

Off Season Moves:

The Giants sought starting pitching help in the off season and look to improve with the signing of right hander Matt Morris (14-10 4.11 with the Cardinals in 2005). Morris was signed for three years, $27 million follars. Longtime starter Kirk Rueter was released and Brett Tomko signed as a free agent with the Dodgers. San Francisco traded for Baltimore's Steve Kline (2-4 4.28) and signed Tim Worrell (1-2 4.07). The team lost Scott Eyre to the Cubs via free agency. Veteran first baseman J.T. Snow, who played for 9 seasons with the Giants moved on to the Red Sox, clearing the way for young Lance Niekro to play in more games. Steve Finley (.222 12 54) was also acquired via trade with the Angels in exchange for 3rd Baseman Edgardo Alfonzo. The Giants also picked up Free Agent Mark Sweeney (.294 8 40) who matched his career high in RBI with the Padres in 2005.

2006 Analysis:

The return of slugger Barry Bonds alone should mean a better offense in 2006. Expect the Giants to be better then their 75-87 record in 2005. Finley is an interesting pickup. In 2004 he hit 36 home runs which were a career high. The Giants are hoping that Finley can have a rebound year and can perhaps hit 30 or more home runs hitting along side Bonds and Alou. Sweeney might surprise fans is allowed to hit regularly. Niekro also should blossom with better hitters around him. The lineup is much improved with a healthy Bonds returning.

If Schmidt rebounds and Matt Morris turns in a similar performance as he did last year (14 wins) then the starting rotation will be solid as well. Expect Lowry and Hennessey to also improve in 2006 with more innings under their belts. The Giants are also looking for a full season from closer Armando Benitez which should also help the bullpen. The Giants should be much better in 2006 and will chase the Padres for the NL West title.

Jack Scrafford recommends PlatinumTickets to buy San Francisco Giants tickets.

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Monday, October 29, 2007

Cisco CCNA Certification: Static Routing Tutorial

In studying for your CCNA exam and preparing to earn this valuable certification, you may be tempted to spend little time studying static routing and head right for the more exciting dynamic routing protocols like RIP, EIGRP, and OSPF. This is an understandable mistake, but still a mistake. Static routing is not complicated, but it's an important topic on the CCNA exam and a valuable skill for real-world networking.

To create static routes on a Cisco router, you use the ip route command followed by the destination network, network mask, and either the next-hop IP address or the local exit interface. It's vital to keep that last part in mind - you're either configuring the IP address of the downstream router, or the interface on the local router that will serve as the exit interface.

Let's say your local router has a serial0 interface with an IP address of 200.1.1.1/30, and the downstream router that will be the next hop will receive packets on its serial1 interface with an IP address of 200.1.1.2/30. The static route will be for packets destined for the 172.10.1.0 network. Either of the following ip route statements would be correct.

R1(config)#ip route 172.10.1.0 255.255.255.0 200.1.1.2 (next-hop IP address)

OR

R1(config)#ip route 172.10.1.0 255.255.255.0 serial0 ( local exit interface)

You can also write a static route that matches only one destination. This is a host route, and has 255.255.255.255 for a mask. If the above static routes should only be used to send packets to 172.10.1.1., the following commands would do the job.

R1(config)#ip route 172.10.1.1 255.255.255.255 200.1.1.2 (next-hop IP address)

OR

R1(config)#ip route 172.10.1.1 255.255.255.255 serial0 ( local exit interface)

Finally, a default static route serves as a gateway of last resort. If there are no matches for a destination in the routing table, the default route will be used. Default routes use all zeroes for both the destination and mask, and again a next-hop IP address or local exit interface can be used.

R1(config)#ip route 0.0.0.0 0.0.0.0 200.1.1.2 (next-hop IP address)

OR

R1(config)#ip route 0.0.0.0 0.0.0.0 serial0 ( local exit interface)

IP route statements seem simple enough, but the details regarding the next-hop IP address, the local exit interface, default static routes, and the syntax of the command are vital for success on CCNA exam day and in the real world.

Chris Bryant, CCIE #12933, is the owner of The Bryant Advantage (http://www.thebryantadvantage.com), home of free CCNA and CCNP tutorials! For my FREE "How To Pass The CCNA" or "CCNP" ebook, visit the website and download your copies. Earn your CCNA certification with The Bryant Advantage!

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Tuesday, October 23, 2007

Cisco CCNP/BSCI Certification: BGP Route Reflector Tutorial

When you're studying for your BSCI exam and CCNP certification, you quickly realize that BGP is a whole new world from anything you've previously studies. One topic that sometimes confuses CCNP candidates is when a BGP route reflector needs to be configured. Route reflectors are an excellent workaround for a basic rule of BGP route advertisement that we?ll review in just a moment.

In the following example, the routers R1, R2, and R3 are all in BGP AS 100. This is not a full mesh, however. There are peer relationships between R1-R2 and R1-R3, but not between R2 and R3. R3 is advertising network 3.3.3.0/24 via BGP, and the route is seen on R1. R1's iBGP neighbor, R2 does not see the route, nor would any other iBGP neighbors of R1. Why?

A basic rule of BGP is that a BGP speaker cannot advertise a route to an iBGP neighbor if that route was learned from another iBGP neighbor. Configuring R1 as a route reflector will allow us to circumvent this rule. The entire route reflector process is transparent to the clients, and no configuration is necessary on those clients. We'll configure R1 as a route reflector for both R2 and R3.

R1(config)#router bgp 100

R1(config-router)#neighbor 172.12.123.2 route-reflector-client

3d18h: %BGP-5-ADJCHANGE: neighbor 172.12.123.2 Down RR client config change

R1(config-router)#neighbor 172.12.123.3 route-reflector-client

3d18h: %BGP-5-ADJCHANGE: neighbor 172.12.123.3 Down RR client config change

The BGP adjacencies do come down when this configuration is added, so this isn't something you want to do during a peak traffic time.

Once the adjacencies come back up, R2 will have the route to 3.3.3.0/24.

There are other possible solutions to this iBGP limitation, such as configuring BGP confederations. Those solutions are generally used on larger BGP deployments and with other concerns in mind, though, and configuring route reflectors serves this purpose just as well.


Chris Bryant, CCIE #12933, is the owner of The Bryant Advantage (http://www.thebryantadvantage.com), home of free CCNA and CCNP tutorials, The Ultimate CCNA Study Package, and Ultimate CCNP Study Packages. For a FREE copy of his latest e-books, ?How To Pass The CCNA? and ?How To Pass The CCNP?, visit the website and download your free copies. Get your CCNA certification with The Bryant Advantage!

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Monday, October 22, 2007

San Francisco

The updated edition of the free Access San Francisco guide for travelers with disabilities is now available. The 34-page book offers detailed information about 150 city venues and travel services that have accessible facilities that have been inspected by an ANC access specialist. These include hotels, restaurants, museums, attractions, shopping centers, recreation facilities, public transportation and others. Inspection notes which add extra insight have been included for clarification. For example, one note states, Path of travel from the street to the entrance is rough paving. Contact: 415-391-2000, (TDD) 415-392-0328

The Baylink Ferry Service has expanded its fleet with the addition of the M/V Solano, a high-speed 135-foot catamaran which ferries 300 passengers between Mare Island in Vallejo, San Franciscos Ferry Plaza at Market and Embarcadero, and Pier 41 at Fishermans Wharf. The trip operates daily. Contact: 877-643-3779.

The San Francisco Museum of Craft+Design has opened at 550 Sutter Street. It offers innovative exhibits and educational programs which celebrate the art and artists of contemporary craft and design. The museum features works in progress and displays showing design trends. It also hosts visiting featured exhibitions and artists. Contact: 415-773-0303, www.sfmcd.org

The Asian Art Museum invites visitors to view its copies, cracks, do-it-yourself fix-its and other imperfections among pieces in collections. The Fakes, Copies, and Question Marks: Forensic Investigations of Asian Art exhibit is part science lesson and part crime scene investigation by examining the authenticity of artworks through forensic testing to reveal the sometimes inexact science of classifying art. The exhibit artifacts are drawn primarily from the museums own collection.

Tibet: Treasures from the Roof of the World, June 12-Sept. 11, features nearly 200 sacred objects from the Potala and Norbu Lingka palaces in Tibet. This exhibition offers a rare insight into the artistic and spiritual traditions of the Dalai Lama and his followers. Contact: 415-581-3500

Del Monte Square, located near Fishermans Wharf, is the site of what was once the worlds largest fruit and vegetable cannery which was operated under the Del Monte name starting in the 1920s. The historic buildings are now home to the Argonaut Hotel, The Visitor Center of the San Francisco Maritime National Historic Park, THE CANNERY and a year-round Certified Organic Farmers Market. The renaming of this area honors the roots of this historic site and celebrates early San Francisco commerce and the influence of the Del Monte company. Throughout the complex are displays and landmark signs that describe various aspects of Del Monte Squares history. Events with historical themes are also planned. Contact: 415-771-3112

Amusing America is at the San Francisco Museum and Historical Societys Mus?e M?canique located at Pier 45 at Fishermans Wharf. This free exhibition tells the story of amusement parks found in American cities including San Francisco and how they influenced the lives of many, from the Gilded Age of the 1880s and 90s to World War II. Displays feature many artifacts including the familiar Laughing Sal, an oversized mechanical manikin which greeted visitors to the citys Playland-at-the-Beach. Antique games which were features of various amusement parks, arcades, swimming baths and dance pavilions are also displayed. Contact: 415-537-1105

Day at the Bay, a popular San Francisco entertainment group, has introduced an all-new cabaret program called A Musical Stroll Along Broadway. The program is filled with music, comedy and lots of nostalgia. The package includes the cabaret show plus lunch options at venues featuring a classic Chinese meal or a Greek feast. After the show, docents lead tours to interesting area sites. This is the perfect package for a day trip or mystery trip. Contact: 415-491-4908.

Vampires are not just for Halloween. Vampire Tours of San Francisco offers spooky tours of the gothic side of Nob Hill. The tour guide is Mina Hacker, the vampiress who was made by Count Dracula in 1897 and who has resided in the darker part of this city for over 100 years. She beckons visitors in a fun and entertaining way into the world of vampires and tells tales of their influence in shaping San Francisco as we know it today. Contact: 650-279-1840.

This article is sponsored by: www.grouptravelblog.com

We are in travel business and wants to provide information about the different travel destinations of united states of america.

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Friday, October 19, 2007

Cisco CCNA Certification: Defining And Creating Collision Domains


When you're studying to pass the CCNA exam and earn your certification, you're introduced to a great many terms that are either totally new to you or seem familiar, but you're not quite sure what they are. The term "collision domain" falls into the latter category for many CCNA candidates.

What exactly is "colliding" in the first place, and why do we care? It's the data that is being sent out onto an Ethernet segment that we're concerned with here. Ethernet uses Carrier Sense Multiple Access / Collision Detection (CSMA/CD) to avoid collisions in the first place. CSMA/CD is a set of rules dictating when hosts on an Ethernet segment can and cannot transmit data. Basically, a host that wants to transmit data will "listen" to the ethernet segment to see if another host is currently transmitting. If no one else is transmitting, the host will go forward with its own transmission.

This is an effective way of avoiding a collision, but it is not foolproof. If two hosts follow this procedure at the exact same time, their transmissions will collide on the Ethernet segment and both transmissions will become unusable. The hosts that sent those two transmissions will then send a jam signal out onto the segment, indicating to all other hosts that they should not send data. The two hosts will each start a random timer, and at the end of that time each host will begin the listening process again.

Now that we know what a collision is, and what CSMA/CD is, we need to be able to define a collision domain. A collision domain is any area where a collision can theoretically take place, so only one device can transmit at a time in a collision domain.

In another free CCNA certification tutorial, we saw that broadcast domains were defined by routers (default) and switches if VLANs have been defined. Hubs and repeaters did nothing to define broadcast domains. Well, they don't do anything here, either. Hubs and repeaters do not define collision domains.

Switches do, however. A Cisco switchport is actually its own unshared collision domain! Therefore, if we have 20 host devices connected to separate switchports, we have 20 collision domains. All 20 devices can transmit simultaneously with no danger of collisions. Compare this to hubs and repeaters - if you have five devices connected to a single hub, you still have one large collision domain, and only one device at a time can transmit.

Mastering the definition and creation of collision domains and broadcast domains is an important step toward earning your CCNA and becoming an effective network administrator. Best of luck to you in both these worthwhile pursuits!

Chris Bryant, CCIE #12933, is the owner of The Bryant Advantage , home of free CCNA and CCNP tutorials! Pass the CCNA exam with Chris Bryant!

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Friday, September 28, 2007

Cisco CCNP / BSCI Tutorial: Comparing OSPF And ISIS Hellos

While studying to pass the BSCI exam and preparing to earn your CCNP certification, you'll quickly notice that while OSPF and ISIS are both link-state protocols, there are a lot of differences between the two. One major difference is the way the two protocols handle hello packets.

Hello packets are imperative to keeping OSPF and ISIS adjacencies alive. Since they are both link-state protocols, neither of them will send updates at any specified time. Hello packets are the only method by which routers running OSPF and ISIS can see that a neighboring router is still available.

OSPF gives us some great options when it comes to keeping routing table size down via the use of stub and total stub areas, but to OSPF, a hello packet is a hello packet. ISIS routers are capable of sending two different types of hellos - Level 1 and Level 2.

ISIS routers are classified as Level 1 (L1), Level 2 (L2), and Level 1-2 (L1-L2). By default, Cisco routers are L1-L2 routers; this means that every ISIS-enabled interface will send out both L1 and L2 hellos.

If one of the interfaces is forming only an L1 or L2 adjacency, there's no reason to send out hellos for the other adjacency type. For example, if R1 is forming an L1 adjacency with R2 via its ethernet0 interface, there is no reason to allow the router to transmit L2 hellos. To hardcode a router interface to send only L1 or L2 hellos, use the isis circuit-type command.

R1(config)#interface ethernet0

R1(config-if)#isis circuit-type level-1

Note: To configure this interface to send only L2 hellos, the full command is "isis circuit-type level-2-only", not just "level-2".

This configuration would prevent L2 hellos from being transmitted out ethernet0. While this does save router resources and prevents unnecessary bandwidth usage, there is also no way an L2 adjacency can be formed - so double-check your network topology before using this command!

Chris Bryant, CCIE #12933, is the owner of The Bryant Advantage (http://www.thebryantadvantage.com), home of free CCNA and CCNP tutorials! For my FREE "How To Pass The CCNA" or "CCNP" ebook, visit the website and download your copies. Earn your CCNA certification with The Bryant Advantage!

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Sunday, September 16, 2007

Cisco CCNP Certification: The BGP Weight Attribute

When you're studying for the CCNP certification, especially the BSCI exam, you must gain a solid understanding of BGP. BGP isn't just one of the biggest topics on the BSCI exam, it's one of the largest. BGP has a great many details that must be mastered for BSCI success, and those of you with one eye on the CCIE must learn the fundamentals of BGP now in order to build on those fundamentals at a later time.

Path attributes are a unique feature of BGP. With interior gateway protocols such as OSPF and EIGRP, administrative distance is used as a tiebreaker when two routes to the same destination had different next-hop IP addresses but the same prefix length. BGP uses path attributes to make this choice.

The first attribute considered by BGP is weight. Weight is a Cisco-proprietary BGP attribute, so if you're working in a multivendor environment you should work with another attribute to influence path selection.

The weight attribute is significant only to the router on which it is changed. If you set a higher weight for a particular route in order to give it preference (a higher weight is preferred over a lower one), that weight is not advertised to other routers.

BGP uses categories such as "transitive", "non-transitive", "mandatory", and "optional" to classify attributes. Since weight is a locally significant Cisco-proprietary attribute, it does not all into any of these categories.

The weight can be changed on a single route via a route-map, or it can be set for a different weight for all routes received from a given neighbor. To change the weight for all incoming routes, use the "weight" option with the neighbor command after forming the BGP peer relationships.

R2(config)#router bgp 100

R2(config-router)#neighbor 100.1.1.1 remote-as 10

R2(config-router)#neighbor 100.1.1.1 weight 200

Learning all of the BGP attributes, as well as when to use them, can seem an overwhelming task when you first start studying for your BSCI and CCNP exams. Break this task down into small parts, learn one attribute at a time, and soon you'll have the BGP attributes mastered.

Chris Bryant, CCIE #12933, is the owner of The Bryant Advantage (http://www.thebryantadvantage.com ), home of free CCNA and CCNP tutorials, and The Ultimate CCNA and CCNP Study Packages. For a copy of his FREE "How To Pass The CCNA" or "CCNP" ebook, visit the website and download your copie

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