SUMMARY: Proxyarp daemon for sun4c, Solaris 2.4

From: Allen Witt (
Date: Tue Dec 13 1994 - 23:49:08 CST

SUMMARY: Proxyarp daemon for sun4c, Solaris 2.4

Original question -
>Due to a hard disk failure on a sun3 which acted as our router I've
>pressed a Sparcstation 1+ running Solaris 2.4 into service as a
>router. Because of the partially subnetted network here I have to run
>a proxyarp server.
>Does anyone know of a proxyarp server that runs under Solaris 2,
>preferably public domain or shareware?

The responses
>From: (Gabriel Lawrence)
>could you please share any answers you find to this with me? We are in a
>similar situation (although we still have some non-solaris machines running

I'm not the only sysadmin with this problem then :-)

>From: (Ronald W. Henderson)
>If I understand you right, all suns can perform the functionality you want.
>Look at the man page for arp. You can use the -pub option for publizing any
>ary requests...

>From: (Kevin Sheehan {Consulting Poster Child})
>You shouldn't need one. Sun had a proxy arp special for early 4.x, but
>since then it knows about being on multiple sub-nets.


Yes, a Sun can publish a proxy ethernet number for a HOST on the SAME subnet
but not for a whole subnet on another ethernet interface. Given the network

        backbone subnet 1 subnet 2
        132.181.[!23&&!25].* ___________ 132.181.23.* __________ 132.181.25.*
        ---------------------| router1 |--------------| router |--------------
                         le1 ~~~~~~~~~~~ le0 ~~~~~~~~~~

router1 can made to proxyarp for a host 132.181.23.X but only on interface le0.
There is no way documented or undocumented (that I could find) of making router1
proxyarp for hosts on 132.181.23 and 132.181.25 subnets in response to arp
requests on the backbone because the published arp table entry is associated with
interface le0. This has the bad side effect of router1 responding to arp requests
on subnet 1 for hosts on subnet 1 with its own ethernet address.

So Sun can put proxyarp functionality into their OS but choose not to, preferring
to charge extra for it.

Nobody has yet ported any of the public domain proxyarp packages to Solaris 2.X.

In the interim I'll set a SPARCstation 1 running 4.1.3 up as dedicated router.


Allen Witt email:

This archive was generated by hypermail 2.1.2 : Fri Sep 28 2001 - 23:09:17 CDT