Bug 79891 - Router causes TCP retransmits for windows hosts after "ip_forward: fix inverted local_df test"
Summary: Router causes TCP retransmits for windows hosts after "ip_forward: fix invert...
Status: NEW
Alias: None
Product: Networking
Classification: Unclassified
Component: IPV4 (show other bugs)
Hardware: All Linux
: P1 normal
Assignee: Stephen Hemminger
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2014-07-10 13:20 UTC by Theodor Milkov
Modified: 2016-02-15 20:18 UTC (History)
2 users (show)

See Also:
Kernel Version: 3.2.60
Subsystem:
Regression: No
Bisected commit-id:

Attachments
TCP retransmissions from a windows host (12.13 KB, application/vnd.tcpdump.pcap)
2014-07-10 13:20 UTC, Theodor Milkov 		Details
Add an attachment (proposed patch, testcase, etc.)

Description Theodor Milkov 2014-07-10 13:20:06 UTC 
Created attachment 142651 [details]
TCP retransmissions from a windows host

After upgrading a router to Linux 3.2.60 most windows machines behind it started experiencing connection stalls. Downgrade to 3.2.59 resolved the problem. Using git bisect I pinpointed it to "59d9f389df3cdf72833d5ee17c3fe959b6bdc792 is the first bad commit", which entered the kernel from here http://marc.info/?l=linux-netdev&m=139949081418806&w=2

No connection problems for Linux hosts at all – only windows. Please, find attached tcpdump packet capture demonstrating the bad behaviour.
Comment 1 Theodor Milkov 2014-07-11 05:44:45 UTC 
I wonder if this is the same bug discussed in the Debian bug tracker: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=754294
Comment 2 Florian Westphal 2014-07-11 21:57:28 UTC 
I guess it would be fixed by applying

commit 21d1196a35f5686c4323e42a62fdb4b23b0ab4a3
ipv4: set transport header earlier

to 3.4 series.
Comment 3 Theodor Milkov 2014-07-12 10:35:59 UTC 
Latest development: http://marc.info/?l=linux-netdev&m=140511646508963&w=2
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