Bug 733417

Summary: The network-bridge script does not set the MTU of the bridge to match the MTU of the physical interface
Product: Red Hat Enterprise Linux 5 Reporter: Paolo Bonzini <pbonzini>
Component: xenAssignee: Paolo Bonzini <pbonzini>
Status: CLOSED ERRATA QA Contact: Virtualization Bugs <virt-bugs>
Severity: high Docs Contact:
Priority: medium    
Version: 5.6CC: drjones, jzheng, leiwang, mrezanin, pbonzini, plyons, qguan, qwan, xen-maint, yuzhang
Target Milestone: rcKeywords: ZStream
Target Release: ---   
Hardware: x86_64   
OS: Linux   
Whiteboard:
Fixed In Version: xen-3.0.3-134.el5 Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of: 697310 Environment:
Last Closed: 2012-02-21 05:55:44 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:
Bug Depends On: 697310    
Bug Blocks: 699611, 738610    

Description Paolo Bonzini 2011-08-25 16:30:57 UTC 
After configuring two machines (e.g. connected with a crossover cable) to use jumbo frames like this:

# Intel Corporation 82574L Gigabit Network Connection
DEVICE=eth0
HWADDR=00:21:5E:6E:F0:29
ONBOOT=yes
HOTPLUG=no
IPADDR=169.254.100.200
NETMASK=255.255.0.0
NETWORK=169.254.0.0
MTU=9000

and similarly on the other machine, the Xen bridge will not be created with MTU set to 9000.  This is necessary for the bridge to work with large MTU:

ip link set mtu 9000 dev vif0.1
ip link set mtu 9000 dev peth0
ip link set mtu 9000 dev xenbr0

The network-bridge script (and friends) should be changed so that this happens automatically.
Comment 1 Paolo Bonzini 2011-08-26 10:04:51 UTC 
The patch depends on the one for bug 697310.
Comment 3 Miroslav Rezanina 2011-09-07 11:44:47 UTC 
Fix built into xen-3.0.3-134.el5
Comment 7 Qixiang Wan 2011-11-15 08:59:58 UTC 
Change to verified per bug 697021 comment 37 and bug 733416 comment 12.
Comment 8 errata-xmlrpc 2012-02-21 05:55:44 UTC 
Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

http://rhn.redhat.com/errata/RHBA-2012-0160.html