Red Hat Bugzilla – Bug 213015
broken xen networking
Last modified: 2007-11-30 17:11:47 EST
Description of problem:
When xend, starts my eth0 interface becomes inoperable. When booting with a
non-xen enabled kernel, or a xen-enabled kernel with xend disabled, my eth0
starts and DHCPs without incident. As soon as Xend is started, the bridges are
created, and my eth0 stops functioning.
Version-Release number of selected component (if applicable):
Steps to Reproduce:
1.Boot a xen-enabled kernel with xend running
2.try to use your network connection
Cannot connect anywhere
To be able to go somewhere
This is a Dell Poweredge 1950.
Tested on same phyical host under the i386 version and I find the same problem
I can provide anything you need to help debug this problem
Please give us some basic information about your network config. Without that
we cannot help at all; networking is working fine under -xen on multiple test
boxes for me. Thanks!
I honestly have no idea what to tell you or what you'd like to see. I'm
connected on eth0 to my network(Eth0 uses the bnx2 module) and if the Xen daemon
is off, I can DHCP and everything works fine. I get an IP. I can ping.
If I start the xen daemon, evertything stops working. I lose my IP address on
eth0. I see no traffic on eth0 via tcpdump. If I turn off the xend service and
down/up the interfaces, things do not return to normal. No other interfaces
I've even tried plugging in a USB NIC to see if it was a driver problem with the
built-in NICs and it doesn't work either. IPtables and selinux are both off.
Let me know specifically what would help and I'll get it to you. I can give you
access to the host if you'd like as well.
Some general info about your networking configuration. To start with the output
from the follows commands would be useful:
iptables -L -n -a
If you can get this info before and after strarting the xend service, that'd be
Created attachment 139874 [details]
requested information about problem
Created attachment 140102 [details]
Created attachment 140103 [details]
route -n (IPv4)
Created attachment 140104 [details]
route -A inet6 -n (IPv6)
Created attachment 140105 [details]
Networking problems under Xen are not only 64-bit related,
because on my Pentium 4 (i686) workstation I also have networking
My workstation is configured for DHCP, and IPv4 works as expected.
But IPv6 is broken. I get a Link local address, and a Global IPv6
address (of course, both of them work). But I cannot get anywhere
outside of my box with IPv6, even not to other IPv6 machines on the
same network. Tested with ping (ICMP) and ssh (TCP).
With the old-school non-Xen kernel (i686), everything is fine.
(sorry, I better should have archived the attachments into one file)
This problem is not fixed by the kernel-2.6.18-1.2849 xen kernel.
This is the same issue as #204534 which is on its way to being resolved.
Super! Except that noone can see that bug. Is it possible to get a short
description what the problem is? Kernel? Xen? Somewhere in between?
It's a core kernel bnx2 driver firmware bug that is triggered by Xen's bridging
FYI I have identical behaviour to the submitter on an Opteron system with Tigon
network interfaces (Tigon3 [partno BCM95721], Rev 401, PHY(5750), PCI Express
Created attachment 144248 [details]
[BNX2]: Fix Xen problem.
This patch will appear in 2.6.20.
[BNX2]: Fix Xen problem.
This fixes the problem of not receiving packets in the Xen bridging
environment. The Xen script sets the device's MAC address to
FE:FF:FF:FF:FF:FF and puts the device in promiscuous mode. The
firmware had problem receiving all packets in this configuration.
New firmware and setting the PROM_VLAN bit when in promiscuous mode
will fix this problem.
Signed-off-by: Michael Chan <firstname.lastname@example.org>
Signed-off-by: David S. Miller <email@example.com>
The rawhide kernel now has 2.6.20-rc1 which contains the fix.
*** Bug 220454 has been marked as a duplicate of this bug. ***