two directors - one works the other doesn't

[Nigel Hamilton]

We have two clusters doing IPIP tunnelling.

This morning one failed. Ethereal shows incoming packets for the VIP 
interfaces on both directors.

The failing director, however gives no [ACK] response. Any ideas on why 
this would happen?

The network interface on the failing director is:


eth0      Link encap:Ethernet  HWaddr 00:0C:76:61:C1:7F
          inet addr:66.98.226.52  Bcast:66.98.227.255  Mask:255.255.254.0
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:2899044 errors:0 dropped:0 overruns:0 frame:0
          TX packets:1539095 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:243188001 (231.9 Mb)  TX bytes:151507144 (144.4 Mb)
          Interrupt:11 Base address:0xe000

lo        Link encap:Local Loopback
          inet addr:127.0.0.1  Mask:255.0.0.0
          UP LOOPBACK RUNNING  MTU:16436  Metric:1
          RX packets:8 errors:0 dropped:0 overruns:0 frame:0
          TX packets:8 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:928 (928.0 b)  TX bytes:928 (928.0 b)

lo:0      Link encap:Local Loopback
          inet addr:66.98.227.143  Mask:255.255.255.255
          UP LOOPBACK RUNNING  MTU:16436  Metric:1
          RX packets:2899044 errors:0 dropped:0 overruns:0 frame:0
          TX packets:1539095 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:243188001 (231.9 Mb)  TX bytes:151507144 (144.4 Mb)


We don't see any incoming packets on the VIP interface of the real 
server with the broken director ... why would the failing director not 
show [ACK] responses?


Nige