Bug 748795

Summary: Bridge stops bridging with kernel 2.6.18-274.7.1
Product: Red Hat Enterprise Linux 5 Reporter: chris <chricki>
Component: kernelAssignee: Neil Horman <nhorman>
Status: CLOSED INSUFFICIENT_DATA QA Contact: Red Hat Kernel QE team <kernel-qe>
Severity: high Docs Contact:
Priority: unspecified    
Version: 5.7CC: jsh, kbsingh, nhorman, pasteur, twoerner
Target Milestone: rc   
Target Release: ---   
Hardware: i686   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of: Environment:
CentOS 5.7
Last Closed: 2012-05-02 13:46:36 UTC Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:

Description chris 2011-10-25 12:03:36 UTC
Description of problem:

After upgrading from 2.6.18-238.19.1 to 2.6.18-274.7.1), a bridge that I created does not forward packets. iptables and arptables don't have rules and their default policies are ACCEPT for all chains, ebtables is not installed.

Setup:

 ++++++++             +++++++++
 + eth1 +++++ br1 +++++ tapbs +
 ++++++++             +++++++++

Specifically, the tcpdump during `arping -I br1 192.168.1.1 -b` (Ethernet broadcasts) is:

[root@lyon ~]# tcpdump -nn -i eth1
13:13:52.633250 arp who-has 192.168.1.1 (ff:ff:ff:ff:ff:ff) tell 192.168.1.2
13:13:53.633700 arp who-has 192.168.1.1 (ff:ff:ff:ff:ff:ff) tell 192.168.1.2
13:13:54.634154 arp who-has 192.168.1.1 (ff:ff:ff:ff:ff:ff) tell 192.168.1.2

[root@lyon ~]# tcpdump -nn -i br1
13:16:07.636627 arp who-has 192.168.1.1 (ff:ff:ff:ff:ff:ff) tell 192.168.1.2
13:16:08.636920 arp who-has 192.168.1.1 (ff:ff:ff:ff:ff:ff) tell 192.168.1.2
13:16:09.637974 arp who-has 192.168.1.1 (ff:ff:ff:ff:ff:ff) tell 192.168.1.2

[root@lyon ~]# tcpdump -nn -i tapbs
(CTRL+C after 10 secs)
0 packets captured
0 packets received by filter
0 packets dropped by kernel

[root@lyon ~]# brctl show
bridge name     bridge id               STP enabled     interfaces
br1             8000.000bcd6d2eda       no              tapbs
                                                        eth1

Version-Release number of selected component (if applicable):

[root@lyon ~]# uname -a
Linux my.hostname.net 2.6.18-238.19.1.el5 #1 SMP Fri Jul 15 07:32:29 EDT 2011 i686 i686 i386 GNU/Linux


How reproducible:

Set up bridge environment as follows.

Steps to Reproduce:
1. brctl addbr br1
2. ifconfig br1 192.168.1.2
3. ifconfig br1 up
4. ifconfig eth1 up
5. brctl addif br1 eth1
6. tunctl -t tapbs -u <user>
7. ifconfig tapbs up
8. brctl addif br1 tapbs
9. arping -I eth1 -b 192.168.1.1

Actual results:

tcpdump shows packets on br1 and eth1, but not on tapbs

Expected results:

All broadcast packets on br1 should go to both eth1 and tapbs.

Additional info:

Occured after update to 2.6.18-274.7.1. Booting an older kernel solves the issue.

Comment 1 Thomas Woerner 2011-10-25 12:44:35 UTC
Reassigning to kernel.

Comment 2 Neil Horman 2012-01-23 13:19:22 UTC
what does the output of brctl showmacs br1 produce?

Comment 3 Neil Horman 2012-03-08 19:40:47 UTC
ping any response?

Comment 4 Neil Horman 2012-05-02 13:46:36 UTC
closing due to lack of response