Suddenly - erratic ping times to reach 4500 Switch

[jdoebling]

I have a network switch that has started to generate alarm in iMC. the ping times to reach the switch range from 1ms up to 473ms. (The switch is connected with a 1 Gbps fiber link into an A7500 core.) I ran a ping plotter graph and the resp. times run around 1ms, but once every minute they jump to 100-473ms, then back down.

Utilization on the switch & the core is low. (both traffic and CPU).

When I telnet into the switch, I dont notice any lagging in responses. The switch shows no errors or other alarms.

The edge switch is a (3Com, now HP) 4500 26 port, running version V3.03.02s168p11 (the most current version that is available).

 

[VinceWhirlwind]

Did you definitely check the CPU utilisation *during* one of these ping events?

The switch gives fairly low priority to responding to pings - try a continuous ping between two other devices via this switch to see if there's anything happening to the actual traffic.

Check the log on the switch.

CHeck switchport utilisation for every switchport on the switch to see if there's a burst of something coming from somewhere.