Craig Tompkins - CCIE #16921
The Network Expert is a blog about computer networking focusing on routing, switching, security, the Expert Cisco Certifications, CCIE & CCDE, and their topics. It's goal to is to document these topics for study and continued knowledge.
Friday, October 31, 2008
Quote of the Week - 10/31/08
"The man who makes a success of an important venture never wails for the crowd. He strikes out for himself. It takes nerve, it takes a great lot of grit; but the man that succeeds has both. Anyone can fail. The public admires the man who has enough confidence in himself to take a chance. These chances are the main things after all. The man who tries to succeed must expect to be criticized. Nothing important was ever done but the greater number consulted previously doubted the possibility. Success is the accomplishment of that which most people think can't be done." - C. V. White
Monday, October 27, 2008
Quick Lists - OSPF Information
A Quick List on general OSPF information brought to you by Packet Life.
http://packetlife.net/static/cheatsheets/ospf.pdf
Packet Life Cheat Sheets
http://packetlife.net/cheatsheets/
Download all Packet Life Cheat Sheets
http://packetlife.net/static/cheatsheets/cheatsheets.zip
http://packetlife.net/static/cheatsheets/ospf.pdf
Packet Life Cheat Sheets
http://packetlife.net/cheatsheets/
Download all Packet Life Cheat Sheets
http://packetlife.net/static/cheatsheets/cheatsheets.zip
Friday, October 24, 2008
Quote of the Week - 10/24/08
"The difference between a successful person and others is not a lack of strength, not a lack of knowledge, but rather a lack in will." - Vince Lombardi
Tuesday, October 21, 2008
Mobile CCIE Lab Exam
As seen here:
https://cisco.hosted.jivesoftware.com/docs/DOC-3224
Mobile CCIE Labs are currently only available for CCIE Routing & Switching Lab Exam Candidates
Cisco has introduced the mobile lab program to provide candidates greater access to Lab testing while greatly reducing travel time and expenses. Mobile CCIE Labs provide a convenient and cost-effective method for candidates to test for CCIE Routing and Switching in areas which do not have permanent lab locations.
The Mobile CCIE Lab reduces the need for costly travel, hotel, passport, and visa fees, missed days of work and the need to leave the country to take the CCIE Lab exam.
Map of Cisco Lab Locations and proposed Mobile Labs
Scheduled Dates/Locations
Lab Location Dates
Johannesburg, South Africa Nov 24-28
Seoul, Korea Dec 8-12
Kuala Lampur, Malaysia Jan 12-16
Riyadh, Saudi Arabia Jan 17-21
Bucharest, Romania Feb 2-6
Kiev, Ukraine Feb 9-13
Osaka, Japan Feb 17-21
Moscow, Russia Feb 23-27
New Delhi, India Mar 2-6
Lagos, Nigeria Mar 9-13
Jakarta, Indonesia Mar 16-20
Ho-Chi-Minh City, Vietnam Apr 6-10
Johannesburg, South Africa Apr 13-17
Shanghai, PR China Apr 20-24
Moscow, Russia May 4-8
Amman, Jordan May 18-22
Miami, Florida May 25-29
Singapore, Singapore Jun 8-12
Riyadh, Saudi Arabia Jun 20-24
Moscow, Russia Aug 3-7
We reserve the right to cancel any mobile event if the registrations do not meet the minimum requirements.
How Do I Get Started?
For information on registering for a CCIE Mobile Lab event or for additional information about the CCIE Mobile Lab program, visit the Certification Online Support tool. Get Instant Answers to Frequently Asked Questions on the Mobile CCIE Labs
View the Discussion CCIE Mobile Lab Now Available!
For specific information on the Lab Exam visit the
CCIE Routing & Switching Lab Exam Overview Page which will include information on the following topics:
▪ Lab Environment
▪ Lab Exam Grading
▪ Results
▪ Reevaluation of Lab Results
▪ Routing and Switching Lab Locations Fixed Locations
▪ CCIE Policies
https://cisco.hosted.jivesoftware.com/docs/DOC-3224
Mobile CCIE Labs are currently only available for CCIE Routing & Switching Lab Exam Candidates
Cisco has introduced the mobile lab program to provide candidates greater access to Lab testing while greatly reducing travel time and expenses. Mobile CCIE Labs provide a convenient and cost-effective method for candidates to test for CCIE Routing and Switching in areas which do not have permanent lab locations.
The Mobile CCIE Lab reduces the need for costly travel, hotel, passport, and visa fees, missed days of work and the need to leave the country to take the CCIE Lab exam.
Map of Cisco Lab Locations and proposed Mobile Labs
Scheduled Dates/Locations
Lab Location Dates
Johannesburg, South Africa Nov 24-28
Seoul, Korea Dec 8-12
Kuala Lampur, Malaysia Jan 12-16
Riyadh, Saudi Arabia Jan 17-21
Bucharest, Romania Feb 2-6
Kiev, Ukraine Feb 9-13
Osaka, Japan Feb 17-21
Moscow, Russia Feb 23-27
New Delhi, India Mar 2-6
Lagos, Nigeria Mar 9-13
Jakarta, Indonesia Mar 16-20
Ho-Chi-Minh City, Vietnam Apr 6-10
Johannesburg, South Africa Apr 13-17
Shanghai, PR China Apr 20-24
Moscow, Russia May 4-8
Amman, Jordan May 18-22
Miami, Florida May 25-29
Singapore, Singapore Jun 8-12
Riyadh, Saudi Arabia Jun 20-24
Moscow, Russia Aug 3-7
We reserve the right to cancel any mobile event if the registrations do not meet the minimum requirements.
How Do I Get Started?
For information on registering for a CCIE Mobile Lab event or for additional information about the CCIE Mobile Lab program, visit the Certification Online Support tool. Get Instant Answers to Frequently Asked Questions on the Mobile CCIE Labs
View the Discussion CCIE Mobile Lab Now Available!
For specific information on the Lab Exam visit the
CCIE Routing & Switching Lab Exam Overview Page which will include information on the following topics:
▪ Lab Environment
▪ Lab Exam Grading
▪ Results
▪ Reevaluation of Lab Results
▪ Routing and Switching Lab Locations Fixed Locations
▪ CCIE Policies
Monday, October 20, 2008
Quick Lists - IS-IS Information
A Quick List on general IS-IS information brought to you by Packet Life.
http://packetlife.net/static/cheatsheets/is-is.pdf
Packet Life Cheat Sheets
http://packetlife.net/cheatsheets/
Download all Packet Life Cheat Sheets
http://packetlife.net/static/cheatsheets/cheatsheets.zip
http://packetlife.net/static/cheatsheets/is-is.pdf
Packet Life Cheat Sheets
http://packetlife.net/cheatsheets/
Download all Packet Life Cheat Sheets
http://packetlife.net/static/cheatsheets/cheatsheets.zip
Friday, October 17, 2008
Quote of the Week - 10/17/08
"Success is the sum of small efforts, repeated day in and day out." - Robert Collier
Thursday, October 16, 2008
CCIE Routing & Switching Lab Exam Blueprint
A link to the CCIE Routing & Switching Lab exam blueprint
http://www.cisco.com/web/learning/le3/ccie/rs/lab_exam_blueprint.html
http://www.cisco.com/web/learning/le3/ccie/rs/lab_exam_blueprint.html
Labels:
CCIE Lab,
Exam Blueprints,
Routing and Switching
Wednesday, October 15, 2008
Frame Relay Broadcast Queue
The broadcast queue for frame relay has 3 limitations, the queue size, the bandwidth, and the packets per second. Once the bandwidth or packets per second threshold is reached, the packets are queued. If the queue hits its limit, the subsequent packets are dropped. It works as a rate-limiting for frame-relay broadcast packets; since the broadcast queue has priority over other traffic, it limits the impact it can have on the interface. The default sizes are 64 queue size, 256,000 bytes per second (2,048,000 bps), and 36 pps. In situations with many individual sub-interfaces, and routing flowing across each sub-interface, the most impacting limitation is packets per second, which when met, starts to fill the queue and cause subsequent drops.
EIGRP as an example uses multicast hellos for neighbor discovery and management. With timers on the interfaces at 5 seconds for hellos, and 3 times that for the hold-interval of 15 seconds, there is a garaunteed packet matching the rates detailed above every 5 seconds minimum. This will begin to limit the numbers of EIGRP neighbors across the frame-relay circuit upon which the sub-interfaces are configured.
This example shows a quick way to look at the frame-relay interfaces on the router and then show the numbers of PVCs. Assuming you have a neighbor on each PVC can give you a quick number to reference.
Router1#sh frame-re pvc | inc Statistics
PVC Statistics for interface Serial1/1:1 (Frame Relay DTE)
PVC Statistics for interface Serial1/1:2 (Frame Relay DTE)
PVC Statistics for interface Serial1/1:4 (Frame Relay DTE)
PVC Statistics for interface Serial1/1:5 (Frame Relay DTE)
PVC Statistics for interface Serial1/1:6 (Frame Relay DTE)
Router1#sh frame-re pvc | inc Local
Local 47 2 1 0
Local 64 1 1 0
Local 37 1 0 0
Local 213 10 9 0
Local 109 3 2 0
The below example shows the interface above the default 36 packets per second, filling up the broadcast queue, and subsequently dropping broadcasts.
Router1#sh int serial1/1:6
Serial1/1:6 is up, line protocol is up
Anywhere we see drops or a queue filling up, we should look at implementing the broadcast-queue changes to alleviate lost hellos and potential adjacency changes.
interface Serial1/1:5
frame-relay broadcast-queue
The numbers used can vary. You want to increase the packets per second enough to compensate for increased hellos, but keep the bandwidth conservative enough to keep that usage low.
Here is the output of Router1 s1/1:5. About twice as many neighbors and a small fraction of the drops of s1/1:6
Router1#sh int s1/1:5
Serial1/1:5 is up, line protocol is up
An example of the log messages generated when a neighbor goes down and comes back up, due to this issue.
Jan 14 00:45:41.038 PST: %DUAL-5-NBRCHANGE: IP-EIGRP(0) 200: Neighbor 10.1.1.1 (Serial1/1:6.144) is down: holding time expired
Jan 14 00:45:49.238 PST: %DUAL-5-NBRCHANGE: IP-EIGRP(0) 200: Neighbor 10.1.1.1 (Serial1/1:6.144) is up: new adjacency
EIGRP as an example uses multicast hellos for neighbor discovery and management. With timers on the interfaces at 5 seconds for hellos, and 3 times that for the hold-interval of 15 seconds, there is a garaunteed packet matching the rates detailed above every 5 seconds minimum. This will begin to limit the numbers of EIGRP neighbors across the frame-relay circuit upon which the sub-interfaces are configured.
This example shows a quick way to look at the frame-relay interfaces on the router and then show the numbers of PVCs. Assuming you have a neighbor on each PVC can give you a quick number to reference.
Router1#sh frame-re pvc | inc Statistics
PVC Statistics for interface Serial1/1:1 (Frame Relay DTE)
PVC Statistics for interface Serial1/1:2 (Frame Relay DTE)
PVC Statistics for interface Serial1/1:4 (Frame Relay DTE)
PVC Statistics for interface Serial1/1:5 (Frame Relay DTE)
PVC Statistics for interface Serial1/1:6 (Frame Relay DTE)
Router1#sh frame-re pvc | inc Local
Local 47 2 1 0
Local 64 1 1 0
Local 37 1 0 0
Local 213 10 9 0
Local 109 3 2 0
The below example shows the interface above the default 36 packets per second, filling up the broadcast queue, and subsequently dropping broadcasts.
Router1#sh int serial1/1:6
Serial1/1:6 is up, line protocol is up
Anywhere we see drops or a queue filling up, we should look at implementing the broadcast-queue changes to alleviate lost hellos and potential adjacency changes.
interface Serial1/1:5
frame-relay broadcast-queue
The numbers used can vary. You want to increase the packets per second enough to compensate for increased hellos, but keep the bandwidth conservative enough to keep that usage low.
Here is the output of Router1 s1/1:5. About twice as many neighbors and a small fraction of the drops of s1/1:6
Router1#sh int s1/1:5
Serial1/1:5 is up, line protocol is up
An example of the log messages generated when a neighbor goes down and comes back up, due to this issue.
Jan 14 00:45:41.038 PST: %DUAL-5-NBRCHANGE: IP-EIGRP(0) 200: Neighbor 10.1.1.1 (Serial1/1:6.144) is down: holding time expired
Jan 14 00:45:49.238 PST: %DUAL-5-NBRCHANGE: IP-EIGRP(0) 200: Neighbor 10.1.1.1 (Serial1/1:6.144) is up: new adjacency
Tuesday, October 14, 2008
CCIE Routing & Switching Written Exam Blueprint v3
A link to the CCIE Routing & Switching exam blueprint version 3
http://www.cisco.com/web/learning/le3/ccie/rs/wr_exam_blueprint_v3.html
http://www.cisco.com/web/learning/le3/ccie/rs/wr_exam_blueprint_v3.html
Labels:
CCIE Written,
Exam Blueprints,
Routing and Switching
Monday, October 13, 2008
Quick Lists - IPv6 Information
A Quick List on general IPv6 information brought to you by Packet Life.
http://packetlife.net/static/cheatsheets/ipv6.pdf
Packet Life Cheat Sheets
http://packetlife.net/cheatsheets/
Download all Packet Life Cheat Sheets
http://packetlife.net/static/cheatsheets/cheatsheets.zip
http://packetlife.net/static/cheatsheets/ipv6.pdf
Packet Life Cheat Sheets
http://packetlife.net/cheatsheets/
Download all Packet Life Cheat Sheets
http://packetlife.net/static/cheatsheets/cheatsheets.zip
Friday, October 10, 2008
Quote of the Week - 10/10/08
"Nothing can stop the man with the right mental attitude from achieving his goal; nothing on earth can help the man with the wrong mental attitude." - Thomas Jefferson
Monday, October 6, 2008
Quick Lists - IPSec Information
A Quick List on general IPSec information brought to you by Packet Life.
http://packetlife.net/static/cheatsheets/ipsec.pdf
Packet Life Cheat Sheets
http://packetlife.net/cheatsheets/
Download all Packet Life Cheat Sheets
http://packetlife.net/static/cheatsheets/cheatsheets.zip
http://packetlife.net/static/cheatsheets/ipsec.pdf
Packet Life Cheat Sheets
http://packetlife.net/cheatsheets/
Download all Packet Life Cheat Sheets
http://packetlife.net/static/cheatsheets/cheatsheets.zip
Friday, October 3, 2008
Quote of the Week - 10/03/08
"Nothing will ever be attempted if all possible objections must first be overcome." - Samuel Johnson
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