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Bug 560870

Summary: Update Neighbor Cache when IPv6 RA is received on a router
Product: Red Hat Enterprise Linux 5 Reporter: David Ward <david.ward>
Component: kernelAssignee: Thomas Graf <tgraf>
Status: CLOSED ERRATA QA Contact: Hangbin Liu <haliu>
Severity: medium Docs Contact:
Priority: medium    
Version: 5.4CC: haliu, hjia, qcai, rkhan
Target Milestone: rc   
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2011-01-13 21:02:49 UTC Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:
Attachments:
Description Flags
Patch for RHEL 5 adapted from kernel 2.6.32
none
proposed patch none

Description David Ward 2010-02-02 04:01:07 UTC 
Created attachment 388189 [details]
Patch for RHEL 5 adapted from kernel 2.6.32

When processing a received IPv6 Router Advertisement, the kernel creates or updates an IPv6 Neighbor Cache entry for the sender -- but presently this does not occur if IPv6 forwarding is enabled (net.ipv6.conf.*.forwarding = 1), or if IPv6 Router Advertisements are not accepted (net.ipv6.conf.*.accept_ra = 0), because in these cases processing of the Router Advertisement has already halted.

Kernel 2.6.32 fixed this behavior, such that the Neighbor Cache is updated in these other cases, while still avoiding any modification to routes or link parameters, and remaining compliant with RFC 4861.  The relevant patch is:
http://git.kernel.org/?p=linux/kernel/git/stable/linux-2.6.32.y.git;a=commit;h=31ce8c71a3bdab12debb5899b1f6dac13e54c71d

I have adapted this patch slightly to match the RHEL 5 kernel.
Comment 1 David Ward 2010-02-02 04:08:19 UTC 
FYI I have been using this patch against the RHEL 5 kernel for six months, so it has been very well tested internally.
Comment 2 Thomas Graf 2010-08-26 06:39:10 UTC 
Patch looks good.
Comment 4 Thomas Graf 2010-08-26 09:01:11 UTC 
Created attachment 441146 [details]
proposed patch
Comment 5 RHEL Program Management 2010-09-07 23:19:24 UTC 
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
release.
Comment 7 Jarod Wilson 2010-09-15 14:00:04 UTC 
in kernel-2.6.18-221.el5
You can download this test kernel from http://people.redhat.com/jwilson/el5

Detailed testing feedback is always welcomed.
Comment 11 errata-xmlrpc 2011-01-13 21:02:49 UTC 
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,
please follow the link below. You may reopen this bug report
if the solution does not work for you.

http://rhn.redhat.com/errata/RHSA-2011-0017.html