kern/141843: [em] [vlan] Intel txcsum and assigned vlan invoke wrong dst MAC in TCP packets

[Pyun YongHyeon]

The following reply was made to PR kern/141843; it has been noted by GNATS.

From: Pyun YongHyeon <pyunyh at gmail.com>
To: Dennis Yusupoff <dyr at smartspb.net>
Cc: bug-followup at FreeBSD.org
Subject: Re: kern/141843: [em] [vlan] Intel txcsum and assigned vlan invoke wrong dst MAC in TCP packets
Date: Tue, 29 Dec 2009 10:51:19 -0800

 On Mon, Dec 21, 2009 at 11:53:22PM +0000, linimon at freebsd.org wrote:
 > Old Synopsis: Intel txcsum and assigned vlan invoke wrong dst MAC in TCP packets
 > New Synopsis: [em] [vlan] Intel txcsum and assigned vlan invoke wrong dst MAC in TCP packets
 > 
 > Responsible-Changed-From-To: freebsd-bugs->freebsd-net
 > Responsible-Changed-By: linimon
 > Responsible-Changed-When: Mon Dec 21 23:51:33 UTC 2009
 > Responsible-Changed-Why: 
 > Over to maintainer(s).
 > 
 > http://www.freebsd.org/cgi/query-pr.cgi?pr=141843
 
 I'm not sure whether you're seeing one of edge case of em(4)/igb(4)
 checksum offload issue. Personally I couldn't reproduce the issue
 but I guess the checksum offload/TSO handling might cause
 unexpected result. If you disable Tx checksum offload or TSO em(4)
 work as expected, right? If so, would you try the following patch
 and let me know whether it makes any difference?
 
 http://people.freebsd.org/~yongari/em.csum_tso.20091229.patch