DUP! in ping replies to or from server

Hi,
I have not seen this before and am hoping someone on the FreeBSD Forums has.

When ping out from a Server I see quite a few

Code:
64 bytes from 107.6.50.74: icmp_seq=0 ttl=56 time=5.707 ms
64 bytes from 107.6.50.74: icmp_seq=1 ttl=56 time=5.404 ms
64 bytes from 107.6.50.74: icmp_seq=1 ttl=56 time=5.529 ms (DUP!)
64 bytes from 107.6.50.74: icmp_seq=2 ttl=56 time=10.788 ms
64 bytes from 107.6.50.74: icmp_seq=3 ttl=56 time=12.424 ms
64 bytes from 107.6.50.74: icmp_seq=3 ttl=56 time=12.549 ms (DUP!)

Same when ping the Server:

Code:
64 bytes from 68.179.122.137: icmp_seq=0 ttl=56 time=5.067 ms
64 bytes from 68.179.122.137: icmp_seq=1 ttl=56 time=5.151 ms
64 bytes from 68.179.122.137: icmp_seq=2 ttl=56 time=5.048 ms
64 bytes from 68.179.122.137: icmp_seq=2 ttl=56 time=5.083 ms (DUP!)
64 bytes from 68.179.122.137: icmp_seq=3 ttl=56 time=5.950 ms
64 bytes from 68.179.122.137: icmp_seq=4 ttl=56 time=5.299 ms
64 bytes from 68.179.122.137: icmp_seq=5 ttl=56 time=4.983 ms
64 bytes from 68.179.122.137: icmp_seq=5 ttl=56 time=5.047 ms (DUP!)

The network configuration is pretty simple:
Server -> Switch -> wireless network (company has wireless connection to the internet).

Any help would greatly be appreciated.

Thanks.
 
Without knowing your network setup, hard to tell you exactly what it is, but this isn't a FreeBSD specific issue (i don't think anyway), FreeBSD is just reporting duplicate ping responses.

Haven't seen it myself, but this is FreeBSD reporting that it received a packet back for an echo request that already had a response.
 
My first guess would be a card issue, as I've seen this on some of the bad GE cards I used.
But like throAU said, hard to tell without more information.

Why don't you test with large payload, say 1400 bytes, see if you get dups again.
 
I don't get DUP's when I ping those IPs. :)

An odd loop in the network topography between point a and b could kick out a DUP.

A couple of years ago, the Netgear GS105 switches would pass packets fine, but DUP some ICMP packets... firmware upgrade fixed that.

When I see DUP's on a local network, I install arping
Code:
pkg_add -r arping
and 'arping' the IP. That returns all the MAC addresses that are responding to that IP.
 
Yes, the GS105E would reply to every ping. They're not bad other than the silly way of configuring them...the GS108E is probably a better device for not much more (both cheap for managed gig-e, but not really great devices).

Easiest test is to plug a cable between the server and a laptop (if possible, obviously constant production use may prevent this) and see if you get the DUPs then. If you don't it's a route issue, a vlan issue, or is a egotistical device that has to get a word in :)

Are you running spanning tree or any other redundant route stuff?
 
Rudy said:
When I see DUP's on a local network, I install arping
Code:
pkg_add -r arping
and 'arping' the IP. That returns all the MAC addresses that are responding to that IP.

arp-scan is pretty awesome too...I usually impress the MCSE types when I can find their IP before they can :)
 
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