Constant Ping issue on 3750

[SSlacks2a]

Hi,

When on our 3750 Core Stack we get the following when pinging a device on a vlan.

any ideas?

Sending 500, 100-byte ICMP Echos to 172.30.32.161, timeout is 2 seconds:

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!.!!

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!.!!!!

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!.!!!!!!

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!.!!!!!!!!

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!.!!!!!!!!!!

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!.!!!!!!!!!!!!

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!.!!!!!!!!!!!!!!

!!!!!!!!!!

Success rate is 98 percent (493/500), round-trip min/avg/max = 1/2/25 ms

[John Blakley]

Is the device a phone?

[SSlacks2a]

Yes it is

Sent from Cisco Technical Support iPhone App

[John Blakley]

The switch pings too fast. I have Avaya phones, and they're known to have a dos protection mechanism that rate limits icmp packets. I'd assume that a lot of manufacturers do this including Cisco.

HTH,

John

*** Please rate all useful posts ***

[SSlacks2a]

Ah gutted I'm trying to troubleshoot one way audio and I thought I was on to something. I pinged the phone from another phone and got this

PING 172.30.32.57 (84=20+8+56 bytes)
64 bytes from 172.30.32.57: icmp_seq=0. time=0. ms
64 bytes from 172.30.32.57: icmp_seq=0. time=1000. ms
64 bytes from 172.30.32.57: icmp_seq=0. time=2000. ms
64 bytes from 172.30.32.57: icmp_seq=0. time=3000. ms
64 bytes from 172.30.32.57: icmp_seq=0. time=4000. ms
64 bytes from 172.30.32.57: icmp_seq=0. time=5000. ms
64 bytes from 172.30.32.57: icmp_seq=0. time=6000. ms
64 bytes from 172.30.32.57: icmp_seq=0. time=7000. ms
64 bytes from 172.30.32.57: icmp_seq=0. time=8000. ms
64 bytes from 172.30.32.57: icmp_seq=1. time=8000. ms
64 bytes from 172.30.32.57: icmp_seq=1. time=9000. ms
64 bytes from 172.30.32.57: icmp_seq=1. time=10000. ms

Is that normal?

[John Blakley]

Actually, that doesn't look normal to me. What happens if you ping from a workstation instead of a phone? Here's what I get when pinging from a server:

PING 10.10.101.10 (10.10.101.10) 56(84) bytes of data.

64 bytes from 10.10.101.10: icmp_req=1 ttl=63 time=0.446 ms

64 bytes from 10.10.101.10: icmp_req=2 ttl=63 time=0.513 ms

64 bytes from 10.10.101.10: icmp_req=3 ttl=63 time=0.521 ms

64 bytes from 10.10.101.10: icmp_req=4 ttl=63 time=0.790 ms

64 bytes from 10.10.101.10: icmp_req=5 ttl=63 time=0.521 ms