Causes of router/switch hangs?

[Dan Jenkins]

Brian wrote:
> I've also seen
> and heard of various brands of low-end devices like that get goofy under
> very high sustained traffic, and excessive ARPs (filling up ARP table
> memory, etc).
> 
> Heat could also be a factor.
> 
> I've never seen things like this happen with "good" gear (Cisco catalyst
> switches, ProCurve, etc).  I think the best remedy is to take this homeowner
> stuff out of a business environment.

I've frequently had these cheap routers require a power 
cycle. It's not a regular event, but when they call with 
a network problem, that's my first item to check. For 
SOHO use, it's somewhat aggravating. For a production 
environment, it's crazy to use a $29 router on a server. 
People do it though. When they can grab the equipment at 
the Walmart or Compusa down the street, it's hard to 
explain why that's a bad idea until they experience a 
problem.

I had a new client whose "network stopped working." 
After chasing it down, I found a 4 port Netgear stuffed 
in the bottom of the rack enclosure. Apparently the 
(former) IT guy didn't have enough cable runs (from the 
1/3 empty 48 port Cisco) to the rack, but had added more 
servers. So... nine hours of downtime. (They didn't call 
us until they'd worked on it almost a day.)

My opinion is that the units overheat and/or simply 
can't handle high volumes. (Or high volumes make them 
overheat.) I replace them with something better wherever 
possible. It's not worth the time to debug a $29 router.

-- 
Dan Jenkins (dan at rastech.com)
Rastech Inc., Bedford, NH, USA --- 1-603-206-9951
*** Technical Support for over a Quarter Century