Hello everybody,

I’m new to Xen so forgive me if this is already well known issue.

I’m using Ubuntu server 7.04 (feisty) with Xen 3.0.3

Everything works perfectly, apart from networking in NAT mode.

With bridging it works, with NAT it works, well, quite strange.

Namely, pings go through and name resolution works.

But when I try to use anything substantial, then the following happens: TCP connection opens but no further traffic goes through, then the connection just hangs.

It looks like this e.g. by wget:

root@ishtar01-vm01:~# wget http://www.theserverside.com

--12:11:51-- http://www.theserverside.com/

=> `index.html'

Resolving www.theserverside.com... 65.214.43.44

Connecting to www.theserverside.com|65.214.43.44|:80... connected.

HTTP request sent, awaiting response...

Netstat shows one connection in stat FIN_WAIT1

tcp 0 110 10.0.0.51:57142 65.214.43.44:80 FIN_WAIT1

Kernel version:
2.6.19-4-generic #2 SMP Thu Apr 5 06:06:18 UTC 2007 i686 GNU/Linux

Iptables output on Dom0:

root@ishtar01:~# iptables -L -n

Chain INPUT (policy ACCEPT)

target prot opt source destination

Chain FORWARD (policy ACCEPT)

target prot opt source destination

ACCEPT 0 -- 10.0.0.51 0.0.0.0/0 PHYSDEV match --physdev-in vif8.0

ACCEPT udp -- 0.0.0.0/0 0.0.0.0/0 PHYSDEV match --physdev-in vif8.0 udp spt:68 dpt:67

Chain OUTPUT (policy ACCEPT)

target prot opt source destination

Ifconfig Dom0:

root@ishtar01:~# ifconfig

eth0 Link encap:Ethernet HWaddr 00:15:17:21:79:62

inet addr:xx.xx.82.231 Bcast:xx.xx.82.255 Mask:255.255.255.0

UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1

RX packets:1490930 errors:0 dropped:0 overruns:0 frame:0

TX packets:10157 errors:0 dropped:0 overruns:0 carrier:0

collisions:0 txqueuelen:100

RX bytes:98378868 (93.8 MiB) TX bytes:1292258 (1.2 MiB)

Base address:0x2000 Memory:e8180000-e81a0000

eth0:1 Link encap:Ethernet HWaddr 00:15:17:21:79:62

inet addr:10.0.0.1 Bcast:10.0.0.255 Mask:255.255.255.0

UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1

Base address:0x2000 Memory:e8180000-e81a0000

lo Link encap:Local Loopback

inet addr:127.0.0.1 Mask:255.0.0.0

UP LOOPBACK RUNNING MTU:16436 Metric:1

RX packets:52 errors:0 dropped:0 overruns:0 frame:0

TX packets:52 errors:0 dropped:0 overruns:0 carrier:0

collisions:0 txqueuelen:0

RX bytes:6174 (6.0 KiB) TX bytes:6174 (6.0 KiB)

vif8.0 Link encap:Ethernet HWaddr FE:FF:FF:FF:FF:FF

inet addr:10.0.0.178 Bcast:0.0.0.0 Mask:255.255.255.255

UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1

RX packets:103 errors:0 dropped:0 overruns:0 frame:0

TX packets:45 errors:0 dropped:0 overruns:0 carrier:0

collisions:0 txqueuelen:0

RX bytes:10547 (10.2 KiB) TX bytes:5403 (5.2 KiB)

DomU config:

root@ishtar01:~# cat /etc/xen/vm01.cfg

kernel = "/boot/vmlinuz-2.6.19-4-generic"

ramdisk = "/boot/initrd.img-2.6.19-4-generic"

builder='linux'

memory = 256

name = "vm01"

vcpus = 1

vif = [ 'ip=10.0.0.51' ]

disk = ['phy:vg01/vm01,sda1,w','phy:vg01/vm01-swap,sda2,w']

root = "/dev/sda1 ro"

in /etc/xen/xend-config.sxp, the following is enabled:

(network-script network-nat)

(vif-script vif-nat)

Any ideas where to look further?

Kind regards,

Timur