proxy_arp / pppoe-server / arp cache persistence problem

["Wojciech Ziniewicz" <wojciech.ziniewicz@gmail.com>]

Hello
I have pppoe server with about 200-500 clients online - all of them
have public IP adresses and I use a "proxyarp" option in my pppoe
server what means the same as proxy_arp in /proc/sys/net but only for
my pppX interfaces (not for eth0, eth1 etc )

A typical entry in arptable looks like this :

? (217.10.10.10) at * PERM PUP on eth0

Some of my clients have long uptime of their routers (i suppose this
is the cause)  and after some time they cannot contact with other
machines in my public subnet  217.10.10.x

When i tried to troubleshoot the problem i've found that machine's
that they can;t reach have an "<incomplete>" arp entry like :

? (217.10.10.10) at <incomplete> on eth1

then i've checked on the main router (pppoe-server)

arp -an | grep 217.10.10.10 ->  gives nothing


My question is - how to adjust the pppoe-server proxy_arp function to
hold the arp entry forever/until_next_change ?


kernel 2.6.15
newest rp.pppoe server

regards

-- 
Wojciech Ziniewicz
Unix SEX :{look;gawk;find;sed;talk;grep;touch;finger;find;fl
ex;unzip;head;tail; mount;workbone;fsck;yes;gasp;fsck;more;yes;yes;eje
ct;umount;makeclean; zip;split;done;exit:xargs!!;)}