Ping times on Cisco 2900

[Rusty500]

I have two Cisco 2900XL routers.

On both of them, ping time to the local IP of the switch itself or between the switch and boxes connected to it are erratic.

Ping times (all 100Mbps, full duplex) range from <1ms - 80ms. This doesn't seem &quot;normal&quot; on a switched 100Mbps network.

I upgraded one of them to the latest software, which didn't fix much and actually &quot;broke&quot; the web-based management software, but that's another story.

In any case, even pinging the switch's IP from the switch gives me ping times that are somewhat erratic.

Any ideas?

Thanks,
Russell

 

[BuckWeet]

You might try replacing the uplink cables, it could be a bad cable itself. Also make sure they're forced to 100mb/full duplex on both ports of the uplink connection..

You also might check to make sure there aren't any broadcast storms or such going on..


BuckWeet

 

[Rusty500]

Thanks for the advice... I did attempt to force 100mb/full duplex. Still had the same problems.

The facility did testing of the uplink (crossover) and the cable between the box and the main machine.

I thought it was a cable problem at first too, but even when I telnet to the switch and ping it from itself, I get something like:

!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 1/2/5 ms

Is that normal? You'd think it'd be 1/1/1, wouldn't you? I'm not aware of any broadcast storms... I'd have to look into that.

Thanks,
Russell

 

[BuckWeet]

nah, 1/2/5 is fine.. The switches are there to switch frames, not to really be processing ICMP packets..

 

[Rusty500]

So when pinging the switch from another box, is it normal to see these erratic ping times? Sometimes the ping times are as bad as 140ms on the local network... normally ping time is about 1ms, but it erratically jumps up every so often.

Thanks for the input,
Russell

 

[vipergg]

This normal , the switches put icmp responses at the low end of the priority list thus they will be longer than you think they should be . to get true readings you need to ping thru the device such as a persons pc from one pc to another and see what the response times are . You should use switch or even router interfaces as a baseline only as a general idea as to how everything is working .

 

[baddos]

How is the CPU utilization? You shouldn't be getting a 80ms ping from one host to another on the same subnet ever. Pings that very by a few ms. is fine, but not by 80ms.