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proxy_arp / pppoe-server / arp cache persistence problem

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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 "" arp entry like :

? (217.10.10.10) at 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!!;)}

--

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proxy_arp / pppoe-server / arp cache persistence problem

Submitted by Wojciech Ziniewicz on Tue, 2008-01-29 14:00.

2008/1/29, Wojciech Ziniewicz :
> 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 )

[...]

hey - i've found a nice arp setting : net.ipv4.neigh.eth0.base_reachable_time

from man 7 arp :

" Once a neighbor has been found, the entry is considered to
be valid for at least a random value (...) Defaults to 30 seconds."

My next questions :

- can I adjust it to be "0" - will it mean "infinite" ?

- why there's so short default time of re-sending the arp cache
refresh for and ip address ?

--
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!!;)}

--

»

proxy_arp / pppoe-server / arp cache persistence problem

Submitted by Rodolfo Barbosa on Tue, 2008-01-29 18:00.

Wojciech Ziniewicz escreveu:
> 2008/1/29, Wojciech Ziniewicz :
>> 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 )
>
>
> [...]
>
> hey - i've found a nice arp setting : net.ipv4.neigh.eth0.base_reachable_time
>
> from man 7 arp :
>
> " Once a neighbor has been found, the entry is considered to
> be valid for at least a random value (...) Defaults to 30 seconds."
>
> My next questions :
>
> - can I adjust it to be "0" - will it mean "infinite" ?
>
> - why there's so short default time of re-sending the arp cache
> refresh for and ip address ?
>
>
Ziniewicz,

This time is so short to avoid conflicts between the network hosts` arp
entries and a new host that joins to network.

If this time becomes longer, when we add an new host on the network
it`ll be unreachable.

Regards
--
Rodolfo Barbosa
Lunar Consultoria

--

»

proxy_arp / pppoe-server / arp cache persistence problem

Submitted by Wojciech Ziniewicz on Wed, 2008-01-30 07:00.

2008/1/29, Rodolfo Barbosa :
[...]
> This time is so short to avoid conflicts between the network hosts` arp
> entries and a new host that joins to network.
>
> If this time becomes longer, when we add an new host on the network
> it`ll be unreachable.

new host _with the same ip address_ I suppose ?

--
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!!;)}

--

»
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