[LARTC] neighbor table overflow

[Marco C. Coelho]

I've got a linux router pushing 600-1000 pppoe connections through it.  
I'm getting a screen error "Neighbor Table Overflow" after this box has 
been up for between 1 week and 1 month.  When this is happening, routing 
slows to a crawl if at all.  Then dies.  I've added:

# Added to stop "neighbor table overflow" messages in the kernel
net.ipv4.neigh.default.gc_thresh1=512
net.ipv4.neigh.default.gc_thresh2=2048
net.ipv4.neigh.default.gc_thresh3=4096
# Added to increase IP contrack number (was getting to max)
net.ipv4.ip_conntrack_max=99999

to sysctl.conf to increase the size, but this only seems to delay the 
problem.

Any thoughts?

Marco