Bug 679188 - gpxe virtio-net driver incorrectly hardcodes frame length always as 1514
gpxe virtio-net driver incorrectly hardcodes frame length always as 1514
Status: CLOSED DUPLICATE of bug 672529
Product: Red Hat Enterprise Linux 6
Classification: Red Hat
Component: gpxe (Show other bugs)
All All
unspecified Severity medium
: rc
: ---
Assigned To: john cooper
Virtualization Bugs
: Triaged
Depends On: 678789
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Reported: 2011-02-21 15:29 EST by Matt Domsch
Modified: 2014-07-24 23:46 EDT (History)
8 users (show)

See Also:
Fixed In Version:
Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of: 678789
Last Closed: 2011-03-09 11:31:01 EST
Type: ---
Regression: ---
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Verified Versions:
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oVirt Team: ---
RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: ---

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Description Matt Domsch 2011-02-21 15:29:27 EST
+++ This bug was initially created as a clone of Bug #678789 +++

Created attachment 479710 [details]
virtio-net: set size of transmitted ethernet frame to header + data length

Description of problem:

All ethernet frames sent by gpxe's virtio-net driver have a length of 1514, regardless of the actual size needed to encapsulate the data.  This messes up at least DHCP on some networks, because the DHCP relay agent can't manipulate the "full" ethernet frame.  This was causing KVM PXE failures for me since the DHCP transaction wouldn't complete.

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

How reproducible:

Steps to Reproduce:
1. Use virt-manager to create a VM with network driver virtio
2. Try to PXE boot the VM
3. Monitor the traffic--all frames have an ethernet length of 1514
Actual results:
fail to boot via PXE

Expected results:
Should boot via PXE.  virtio-net should set the ethernet frame length to the actual size of the data to be sent + headers.

Additional info:
See attached patch for the fix.

--- Additional comment from cra@wpi.edu on 2011-02-19 12:29:03 EST ---

Same fix needs to be applied to F13, F14, F15, rawhide/F16, and EL5 branches.  Thanks.

--- Additional comment from lfarkas@lfarkas.org on 2011-02-20 15:05:37 EST ---

what's up with el6?

--- Additional comment from cra@wpi.edu on 2011-02-21 11:58:13 EST ---

Same bug exists in el6.  Could someone who has a RHEL subscription please open a ticket?  Thanks.

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