[NBLUG/talk] OT - DUP packets on a ping.

[Ron Wickersham]

On Thu, 12 Oct 2006, Mark Street wrote:

> Hi,
>
> Could someone shed some light on why I might see this happening?  This seems
> like a networking link? layer problem somewhere?
>
>
> 64 bytes from 10.10.11.60: icmp_seq=0 ttl=127 time=32.2 ms
> 64 bytes from 10.10.11.60: icmp_seq=0 ttl=127 time=32.6 ms (DUP!)

---snip---

two remote interfaces both configured to 10.10.11.60?
to test, turn off a device configured with an interface at that address
and see if the other one is still on.   if so, check it's mac address
and look up the mfgr.   have seen this behavior with a home router/switch
used only as a 4-port switch with a forgotten router config at the
offending address, so the mfgr gave a clue about what the device was.

two paths, perhaps thru duplicate hub/switches and spanning tree turned
off?    radio links?

any other duplicate replies on the same subnet?   on all subnets?

-ron