IP Forward Problems

[Gerard Hooton <g.hooton@ucc.ie>]

Hello,
Fist my system:

Linux uepc004 2.6.24-1-686 #1 SMP Thu May 8 02:16:39 UTC 2008 i686
GNU/Linux

Network:
eth0      Link encap:Ethernet  HWaddr 00:30:48:29:e9:40  
          inet addr:143.239.184.13  Bcast:143.239.255.255
Mask:255.255.0.0 
          inet6 addr: fe80::230:48ff:fe29:e940/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:1751152 errors:0 dropped:0 overruns:0 frame:0
          TX packets:33579 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:174917895 (166.8 MiB)  TX bytes:19228996 (18.3 MiB)
          Base address:0x3000 Memory:f8200000-f8220000 

eth0:0    Link encap:Ethernet  HWaddr 00:30:48:29:e9:40  
          inet addr:143.239.184.12  Bcast:143.239.255.255
Mask:255.255.0.0
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          Base address:0x3000 Memory:f8200000-f8220000 

eth1      Link encap:Ethernet  HWaddr 00:30:48:29:e9:41  
          inet addr:143.239.184.75  Bcast:143.239.255.255
Mask:255.255.0.0
          inet6 addr: fe80::230:48ff:fe29:e941/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:1738672 errors:0 dropped:0 overruns:0 frame:0
          TX packets:228 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:180938419 (172.5 MiB)  TX bytes:20519 (20.0 KiB)
          Base address:0x3040 Memory:f8220000-f8240000 

lo        Link encap:Local Loopback  
          inet addr:127.0.0.1  Mask:255.0.0.0
          inet6 addr: ::1/128 Scope:Host
          UP LOOPBACK RUNNING  MTU:16436  Metric:1
          RX packets:14810 errors:0 dropped:0 overruns:0 frame:0
          TX packets:14810 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 
          RX bytes:20030201 (19.1 MiB)  TX bytes:20030201 (19.1 MiB)


#################### The Problem ################################

I have discovered that with net.ipv4.ip_forward = 1
the  apr table starts to grow and grow and I think I get an arp table
overflow. Also I get No buffer space available errors. When I do
net.ipv4.ip_forward = 0 the arp table reduces to a normal size and the 
No buffer space available errors stop.

Any ideas?

Thanks.

-- 
Gerard Hooton.
Department of Microelectronic Engineering U.C.C.
Butler Building,
Enterprise Centre,
North Mall.
Cork.

Tel: +353 21 4904576
Fax: +353 21 4904573
http://www.ue.ucc.ie/