Re: [Bugme-new] [Bug 7535] New: ARP notifications to NETLINK_ROUTE

On Thu, 16 Nov 2006 01:11:20 -0800
bugme-daemon@bugzilla.kernel.org wrote:

http://bugzilla.kernel.org/show_bug.cgi?id=7535

           Summary: ARP notifications to NETLINK_ROUTE
    Kernel Version: 2.6.16, 2.6.17
            Status: NEW
          Severity: normal
             Owner: shemminger@osdl.org
         Submitter: lyricsfan@lycos.com


Most recent kernel where this bug did *NOT* occur:
2.6.8 (maybe also some later version, but < 2.6.16)

Distribution:
ubuntu 6.06 desktop/server (also with standard kernel 2.6.16), knoppix 5.0.1
(kernel 2.6.17)

Hardware Environment:
irrelevant

Software Environment:
irrelevant

Problem Description:
While listening to the multicast group RTMGRP_NEIGH on a NETLINK_ROUTE socket,
on kernel 2.6.8 a RTM_NEWNEIGH message is received whenever an entry is added or
deleted to the ARP table. On 2.6.16, no such message is received, except for
IPv6 events.
Setting "/proc/sys/net/ipv4/neigh/*/app_solicit" to a value > 0 doesn't solve
the problem.

Steps to reproduce:
Open a NETLINK_ROUTE socket and listen to RTMGRP_NEIGH. Try to add a new entry
to the ARP table, either manually or by pinging a neighbour on the same subnet.
Try also to manually delete an entry, or simply let it expire. No RTM_NEWNEIGH
message is triggered when any of these events occurs (it IS in kernel 2.6.8).