June 2007
Intermediate to advanced
600 pages
18h 19m
English
Content preview from Network WarriorBecome an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.
Troubleshooting Frame Relay
Troubleshooting frame relay is quite simple once you understand how it works. Remember that most of the information regarding PVCs is delivered from the DCE device, which is usually the telecom switch on the far end of your physical link.
The key to any troubleshooting process is problem isolation. You need to determine where the problem lies so you can determine a corrective course of action. Follow these steps, and you'll quickly determine where the trouble is:
- Physical layer first!
Is the cable plugged in? Is the cable a known good cable? Is the cable on the other end plugged in? This may sound silly, but you'll feel pretty foolish if you call Cisco for help only to find that the cause of your woes was an unplugged cable.
- Is the serial link up?
Make sure your serial link is up via a
show interface. Leaving an interface in a shut-down state has a tendency to prevent traffic from being passed over it.- Are you receiving LMI?
Remember that LMI is sent from your locally connected telecom device. If you're not receiving LMI, you're not getting status messages regarding your VCs, so the router will not know that they exist. There are a couple of ways to see whether you're receiving LMI:
show interfaceThe output from a
show interfacecommand for a frame-relay-encapsulated interface will include LMI counters. LMI updates are received every 10 seconds, so executing the command and then waiting 10 seconds or more and executing the command again should show an increase ...
Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
and much more.
Read now
Unlock full access
More than 5,000 organizations count on O’Reilly
O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.Julian F.
I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.Amir M.
I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.