xen discuss - Jul 2010 - packets from DomU on VLAN disappear

Hi,

I have a problem similar to the previous poster (thread: Virtual network of
DomU''s), but apparently not with similar solutions...

Situation:
 - two physical links aggregated to "default0"
 - dladm create-vlan on default0 with several different vlans
 - xVM DomU running linux connected to the same vlans

when trying to ping the DomU from Dom0, I can see with snoop (in Dom0) and
tcpdump (in DomU) that ARP-packets reach the DomU and the DomU answers, but the
replies never reach Dom0.

I have tried approximately the same thing with zones, like this:
http://bugs.opensolaris.org/bugdatabase/view_bug.do?bug_id=6810953
and I am able to ping between all three zones (the global and the two non-global
zones)

My internet-connection is also through a VLAN and the connection to nearest
switch is VLAN-tagged.

It seems:
 - vlans work OK
 - vlans in zones work OK
 - if I configure the DomU-network without a vlan, it also works (which suprise
me, because I would have thought it couldn''t reach the DHCP without
being on the correct vlan).  Pinging the DomU (w/o vlan) from the Dom0
doesn''t work, because Dom0 doesn''t have any interface without
vlan-tagging
 - a DomU on a vlan recieves packets, but return-packets disappear.

How can I debug this?

If the problem is related to MTU, how do I change it?  (I haven''t been
able to change the MTU of the physical interfaces nor the aggregation, vnic-s
are created by xen/virsh-magic)

Output from Dom0:

admin@master:~# dladm show-link
LINK        CLASS    MTU    STATE    OVER
eth0        phys     1500   up       --
eth1        phys     1500   up       --
default0    aggr     1500   up       eth0 eth1
admin0      vlan     1500   up       default0
server0     vlan     1500   up       default0
client0     vlan     1500   up       default0
guest0      vlan     1500   up       default0
tv0         vlan     1500   up       default0
internet0   vlan     1500   up       default0
xvm19_0     vnic     1500   up       default0
xvm19_2     vnic     1500   up       default0
xvm19_1     vnic     1500   up       default0
xvm19_3     vnic     1500   up       default0
admin@master:~# dladm show-vnic
LINK         OVER         SPEED  MACADDRESS           MACADDRTYPE         VID
xvm19_0      default0     100    0:16:3e:0:1:2        fixed               2
xvm19_2      default0     100    0:16:3e:0:1:4        fixed               4
xvm19_1      default0     100    0:16:3e:0:1:3        fixed               3
xvm19_3      default0     100    0:16:3e:0:1:6        fixed               6
admin@master:~# dladm show-vlan
LINK            VID      OVER         FLAGS
admin0          1        default0     -----
server0         2        default0     -----
client0         3        default0     -----
guest0          4        default0     -----
tv0             5        default0     -----
internet0       6        default0     -----
admin@master:~# ifconfig -a
lo0: flags=2001000849<UP,LOOPBACK,RUNNING,MULTICAST,IPv4,VIRTUAL> mtu 8232
index 1
	inet 127.0.0.1 netmask ff000000 
admin0: flags=201000843<UP,BROADCAST,RUNNING,MULTICAST,IPv4,CoS> mtu 1500
index 24
	inet 192.168.16.2 netmask ffffff00 broadcast 192.168.16.255
	ether 0:1f:d0:27:3b:b0 
server0: flags=201000843<UP,BROADCAST,RUNNING,MULTICAST,IPv4,CoS> mtu 1500
index 25
	inet 192.168.32.2 netmask ffffff00 broadcast 192.168.32.255
	ether 0:1f:d0:27:3b:b0 
client0: flags=201000843<UP,BROADCAST,RUNNING,MULTICAST,IPv4,CoS> mtu 1500
index 26
	inet 192.168.48.2 netmask ffffff00 broadcast 192.168.48.255
	ether 0:1f:d0:27:3b:b0 
guest0: flags=201000843<UP,BROADCAST,RUNNING,MULTICAST,IPv4,CoS> mtu 1500
index 27
	inet 192.168.64.2 netmask ffffff00 broadcast 192.168.64.255
	ether 0:1f:d0:27:3b:b0 
internet0: flags=201000843<UP,BROADCAST,RUNNING,MULTICAST,IPv4,CoS> mtu
1500 index 28
	inet 192.168.10.11 netmask ffffff00 broadcast 192.168.10.255
	ether 0:1f:d0:27:3b:b0 
lo0: flags=2002000849<UP,LOOPBACK,RUNNING,MULTICAST,IPv6,VIRTUAL> mtu 8252
index 1
	inet6 ::1/128

btw, I also see ARP-messages from Dom0 asking for it''s own address, for
example:

VLAN#3: 192.168.48.2 -> (broadcast)  ARP C Who is 192.168.48.2, 192.168.48.2
?
VLAN#3: 192.168.48.2 -> (broadcast)  ARP C Who is 192.168.48.2, 192.168.48.2
?
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Seems like a known bug...

http://bugs.opensolaris.org/bugdatabase/view_bug.do?bug_id=6890548
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Am 15.07.2010 07:05, schrieb Rolf rander Næss:
> Seems like a known bug...
> 
> http://bugs.opensolaris.org/bugdatabase/view_bug.do?bug_id=6890548
Just hvm qemu nics were effected here.
PV nics are working fine, by just setting, vlanid=42 f.e., even for
windows hvm guests with gplpv drivers (b134 needed)

Florian

Ok, interresting.  Any hints to how I can set up paravirtualized network in a
linux-vm that is currently without network connectivity?

(I generally find pv confusing to set up, because the kernel is accessed from
Dom0 while the modules it needs to load must be accessible from DomU, and my foo
or bar linux distro will typically not include pv-support...)

why is b134 needed?  (I haven''t been able to upgrade from 111b, but
that is a different story for another thread in another forum...)


rolf rander
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This message posted from opensolaris.org

Am 15.07.2010 13:55, schrieb Rolf rander Næss:
> Ok, interresting.  Any hints to how I can set up paravirtualized network in
a linux-vm that is currently without network connectivity?
> 
> (I generally find pv confusing to set up, because the kernel is accessed
from Dom0 while the modules it needs to load must be accessible from DomU, and
my foo or bar linux distro will typically not include pv-support...)
> 
Pygrub normally could help here.
But I prefer using a monolithic kernel anyway for my guests.
A recent vanilla kernel would do.
> why is b134 needed?  (I haven''t been able to upgrade from 111b,
but that is a different story for another thread in another forum...)
> 
Needed or recomended for use of GPLPV Drivers for windows


Florian

I still can''t figure this out.

What I am trying to accomplish, is to run a linux-based firewall (currently
looking at smoothwall) connected to a set of VLAN-s.  My smoothwall-host
currently has no network connectivity and no gcc, trying to compile anything on
this seems like a difficult venture.  Smoothwall runs on 2.6.16.

The options I am looking at for getting further:
1. booting my smoothwall-image with a pv-kernel
2. adding a pv-over-hvm network driver to the smoothwall image

To be able to compile either a new pv-kernel or pv network drivers, I have tried
installing another linux with some more tools available.

I have tried installing debian lenny according to this description:
http://wiki.debian.org/Xen#DomU.28guest.29

as far as I know, this i linux kernel 2.6.26 with pvops-support.  Xen is unable
to load the kernel:
xc_dom_find_loader: trying ELF-generic loader ... failed
xc_dom_find_loader: trying multiboot-binary loader ... failed
xc_dom_core.c:495: panic: xc_dom_find_loader: no loader found

according til ''file'', the kernel-image is of type:
Linux kernel x86 boot executable RO-rootFS, root_dev 0x6803, swap_dev 0x1,
Normal VGA


Some questions I haven''t been able to find answers to through google:
 - do I need a special version of xen to support pvops?
 - does the one in solaris xVM support pvops?
 - what should be the file-type of the kernel-image for xen to be able to load
it?  (I thought i would have to be ELF, but the netboot/xen-image from debian is
"x86 boot executable" for all available debian-releases)
 - how can I get files in to my smoothwall image without network?  (My guess
would be to create a file-based block-device with some file-system supported
both by solaris and smoothwall, and loopback-mount it in Dom0 to fill it with
data, iso and vfat seems to be my only options)
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