mpls network dropping packets

borderblaster · ‎01-07-2009

We have some strange behaviour at the moment on our remote servers connected using mpls vpn. When I try and ssh to a centos servers it takes up to 1 minute to get a login prompt. If I ping the server there is no reply for sometimes 30 seconds to a minutes and then replies start happening. It looks like a kind of idle disconnect happening? Does anyone know if this could be anything to do with mpls? or could be just coincidence that this is happening on just our remotes sites using mpls.

mheick · ‎01-07-2009

Doesn't sound like an MPLS problem. What happens if you ping the default gateway while you are pinging the server?

borderblaster · ‎01-07-2009

The routing table looks like this

Destination Gateway Genmask Flags Metric Ref Use Iface

192.168.100.0 * 255.255.255.0 U 0 0 0 eth1

192.168.98.0 * 255.255.255.0 U 0 0 0 eth2

192.168.99.0 * 255.255.255.0 U 0 0 0 eth0

169.254.0.0 * 255.255.0.0 U 0 0 0 eth2

default 192.168.100.1 0.0.0.0 UG 0 0 0 eth1

pinging the default gateway at the same time it responds perfectly. Its the remote server that does not respond to ping and then suddenly starts to respond.

--- 192.168.100.1 ping statistics ---

24 packets transmitted, 24 received, 0% packet loss, time 23005ms

rtt min/avg/max/mdev = 0.160/0.238/0.843/0.131 ms, pipe 2

--- 192.168.99.42 ping statistics ---

25 packets transmitted, 6 received, 76% packet loss, time 24006ms

rtt min/avg/max/mdev = 6.419/13.766/50.476/16.417 ms, pipe 2

mheick · ‎01-07-2009

Is there another node in the 192.168.99.x network that you can ping and if so does it look clean like the gateway? If so then you can rule out the MPLS cloud as the issue.