Red Hat Bugzilla – Bug 516589
Kernel netlink neighbor updates not sent to multicast group (RTMGRP_NEIGH)
Last modified: 2010-03-30 03:41:25 EDT
Created attachment 356911 [details]
Backport kernel patches to fix netlink neigh notifications
An application running in user space should be able to monitor updates to the kernel's neighbor table (also known as the ARP table for IPv4). This is done by opening a netlink socket for the address family NETLINK_ROUTE and subscribing to the multicast group RTMGRP_NEIGH.
In kernel 2.6.18, however, the kernel does not send neighbor updates to this multicast group as it should when a neighbor entry is added or administratively removed. This behavior is fixed in kernel 2.6.24 as the result of two upstream patches:
The patches above cannot be applied directly to the 2.6.18 kernel, but I created a working patch for the RHEL 5 kernel that provides the same relevant modifications, which is attached.
This request was evaluated by Red Hat Product Management for inclusion in a Red
Hat Enterprise Linux maintenance release. Product Management has requested
further review of this request by Red Hat Engineering, for potential
inclusion in a Red Hat Enterprise Linux Update release for currently deployed
products. This request is not yet committed for inclusion in an Update
You can download this test kernel from http://people.redhat.com/dzickus/el5
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An advisory has been issued which should help the problem
described in this bug report. This report is therefore being
closed with a resolution of ERRATA. For more information
on therefore solution and/or where to find the updated files,
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