Members of the ISP-Routing list discuss the stability of routers. Servers certainly have their problems, but surely the humble router can be left to itself?

[June 12, 2002]

On the ISP-Routing list in May, JT inquired,

"Our manager is going to be implementing a process to reload all of our Cisco routers on a regular, timed basis. He's tired of dealing with issues that are resolvable just by reloading the routers. Has anyone ever heard of someone doing this? Any thoughts?"

TH contended that scheduling regular reboots is unnecessary for a router:

"I have never heard of regularly rebooting Cisco routers, or any commercial-grade routers. We have had Ciscos with uptimes of 500+ days, and they were only taken down for maintenance, upgrades, etc. I have heard of this done with Windows servers, but there's a lot more going on with a server, and I can better understand the need to reboot occasionally."

Others recommended looking more carefully for the source of the problem:

[AS observed] "It's most unusual to want to reboot a router regularly. Have the issues that require a reboot been firmly identified and is the decision to reboot regularly and automatically a logical conclusion of that investigation, or is the scheduled reboot being instituted because 'the router keeps messing up and needs to be rebooted?' If it's the latter, it's pretty unwise."

[CL agreed] "You should look into why your routers are not stable: you probably have too many different IOS versions to manage, and too little DRAM in some of your routers."

[TH asked] "What is happening that requires a reboot or reload? You might consider opening a TAC Case instead. It might pay for itself in lost productivity."

[SK recalled] "I had a client suggest this once, and I just looked at him like he was nuts. If you are having recurring problems, then solve them. In our case, we did a version audit and upgrade/standardization, and this solved the problems."

Still others offered some advice on how to schedule the reboots:

[CL advised] "Use the scheduled reload capability in IOS to boot the routers at predetermined times, and have a tech check back on the router after the scheduled boot."

[TH noted] "It should be pretty easy to write a script that logs in and runs the reload command, then confirms it. You could put it in cron (or the NT equivalent) to be done automatically at a certain time."

CL acknowledged that, under the right circumstances, scheduled reboots could be the best option:

"It's not a bad idea if you are running IOS with memory or resource leaks. Rather than boot the routers on a scheduled basis, of course, upgrading the IOS to a more rock solid version would be the technically elegant solution. Management is often not interested in the technically elegant solution, though, and will instead opt for a solution that has a little manageable but predictable pain. In other words, management generally likes to boot a router and have a guaranteed seven-minute downtime every 45 days much more than they like to have to boot a router every 365 days after four hours of downtime spent locating an engineer and troubleshooting a problem."

—End