dst cache overflow

[Michael Merhej]

Hello,
Recently we have been experiencing some problems with the network dying
temporarily on a machine then magically coming back to life.  This appears
to happen more frequently when the machines are loaded down CPU wise and
usually sustain over 3Mbits/sec of network traffic.  This is happening on
several machines with similar configurations.  Each machine has about 2000
active tcp connections on them and CPU usage is typically over 75%.  They
have AMD 800-950 processors and 3Com 905C cards running Redhat 6.2 with
kernel build ranges from 2.2.17p3 to 2.2.18p10.

When this happens the below logs appear in the system logger:

Oct  3 12:14:38 onion kernel: dst cache overflow 
Oct  3 12:14:38 onion last message repeated 9 times
Oct  3 12:14:43 onion kernel: NET: 486 messages suppressed. 
Oct  3 12:14:43 onion kernel: dst cache overflow 
Oct  3 12:14:48 onion kernel: RPC: sendmsg returned error 105 
Oct  3 12:14:49 onion kernel: NET: 367 messages suppressed. 
Oct  3 12:14:49 onion kernel: dst cache overflow 
Oct  3 12:14:51 onion kernel: RPC: sendmsg returned error 105 
Oct  3 12:14:53 onion kernel: NET: 192 messages suppressed. 
Oct  3 12:14:53 onion kernel: dst cache overflow 
Oct  3 12:14:55 onion kernel: RPC: sendmsg returned error 105 
Oct  3 12:14:59 onion kernel: NET: 122 messages suppressed. 
Oct  3 12:14:59 onion kernel: dst cache overflow 
Oct  3 12:15:01 onion kernel: nfs: server toastem not responding, still
trying 
Oct  3 12:15:01 onion kernel: RPC: sendmsg returned error 105 
Oct  3 12:15:03 onion kernel: RPC: sendmsg returned error 105 
Oct  3 12:15:04 onion kernel: NET: 52 messages suppressed. 
Oct  3 12:15:05 onion kernel: dst cache overflow 
Oct  3 12:15:08 onion kernel: RPC: sendmsg returned error 105 
Oct  3 12:15:11 onion kernel: nfs: server toastem OK 

Oct  3 09:23:58 mint kernel: NET: 271 messages suppressed. 
Oct  3 09:23:58 mint kernel: dst cache overflow 
Oct  3 09:23:58 mint last message repeated 9 times
Oct  3 09:24:07 mint kernel: NET: 384 messages suppressed. 
Oct  3 09:24:07 mint kernel: dst cache overflow 
Oct  3 09:24:07 mint kernel: NET: 255 messages suppressed. 
Oct  3 09:24:07 mint kernel: dst cache overflow 
Oct  3 09:24:12 mint kernel: NET: 149 messages suppressed. 
Oct  3 09:24:12 mint kernel: dst cache overflow 
Oct  3 09:24:18 mint kernel: NET: 64 messages suppressed. 
Oct  3 09:24:18 mint kernel: dst cache overflow 
Oct  3 09:24:23 mint kernel: NET: 35 messages suppressed. 
Oct  3 09:24:23 mint kernel: dst cache overflow 
Oct  3 09:24:27 mint kernel: NET: 23 messages suppressed. 
.
.

Hope this helps

Thanks

--Michael