Subject: Networking problems
To: None <port-xen@NetBSD.org>
From: Matteo Beccati <php@beccati.com>
List: port-xen
Date: 04/04/2006 20:24:38
Hi,

I've recently switched kernel on my NetBSD 3.0 development server to be 
able to evaluate XEN. I've been able to get it running having dom0 on a 
raidframe mirrored root fs, thanks to the great how-tos. I've managed to 
install another NetBSD 3.0 as domU booting with the INSTALL_XENU kernel 
and installed installing from cdrom.

The domU seems perfectly working, but I'm unable to have a working 
network configuration. If I try to ping any machine in the bridged 
network I receive DUP! answers, but the same doesn't happen when trying 
to reach an external IP (outside of my wireless router, which also acts 
as a dhcp server). I'm also able to resolve IPs, but the whole thing 
stops when trying to make TCP connections anywhere.

 From what I was able to see connections remain in SYN_SENT state. Here 
are some ifconfig/brconfig output:

dom0
----
# ifconfig -a
ste0: 
flags=8b43<UP,BROADCAST,RUNNING,PROMISC,ALLMULTI,SIMPLEX,MULTICAST> mtu 1500
         address: 00:05:5d:e9:f4:50
         media: Ethernet autoselect (100baseTX full-duplex)
         status: active
         inet 192.168.1.100 netmask 0xffffff00 broadcast 192.168.1.255
         inet6 fe80::205:5dff:fee9:f450%ste0 prefixlen 64 scopeid 0x1
lo0: flags=8009<UP,LOOPBACK,MULTICAST> mtu 33192
         inet 127.0.0.1 netmask 0xff000000
         inet6 ::1 prefixlen 128
         inet6 fe80::1%lo0 prefixlen 64 scopeid 0x2
bridge0: flags=41<UP,RUNNING> mtu 1500
xvif1.0: 
flags=8963<UP,BROADCAST,NOTRAILERS,RUNNING,PROMISC,SIMPLEX,MULTICAST> 
mtu 1500
         address: ab:00:00:51:02:f1
         inet6 fe80::205:5dff:fee9:f450%xvif1.0 prefixlen 64 scopeid 0x4

# brconfig -a
bridge0: flags=41<UP,RUNNING>
         Configuration:
                 priority 32768 hellotime 2 fwddelay 15 maxage 20
                 ipfilter disabled flags 0x0
         Interfaces:
                 xvif1.0 flags=3<LEARNING,DISCOVER>
                         port 4 priority 128
                 ste0 flags=3<LEARNING,DISCOVER>
                         port 1 priority 128
         Address cache (max cache: 100, timeout: 1200):
                 00:0f:3d:09:72:91 ste0 780 flags=0<>
                 00:13:d4:88:8e:50 ste0 181 flags=0<>
                 ab:00:00:50:02:f1 xvif1.0 166 flags=0<>


domU
----
# ifconfig -a
lo0: flags=8009<UP,LOOPBACK,MULTICAST> mtu 33192
         inet 127.0.0.1 netmask 0xff000000
         inet6 ::1 prefixlen 128
         inet6 fe80::1%lo0 prefixlen 64 scopeid 0x1
xennet0: flags=8863<UP,BROADCAST,NOTRAILERS,RUNNING,SIMPLEX,MULTICAST> 
mtu 1500
         address: ab:00:00:50:02:f1
         inet 192.168.1.121 netmask 0xffffff00 broadcast 192.168.1.255
         inet6 fe80::d41d:8cd9:8f00:b204%xennet0 prefixlen 64 scopeid 0x2


Netstat and tcpdump of a smtp connection from domU to dom0:

Active Internet connections
Proto Recv-Q Send-Q  Local Address          Foreign Address        State
tcp        0      0  192.168.1.121.65519    192.168.1.100.smtp     SYN_SENT

# tcpdump port smtp &
[1] 623
# tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on xennet0, link-type EN10MB (Ethernet), capture size 96 bytes
# telnet 192.168.1.100 25
Trying 192.168.1.100...
20:20:03.930140 IP 192.168.1.121.65517 > 192.168.1.100.smtp: S 
1411259275:1411259275(0) win 32768 <mss 1460,nop,wscale 
0,sackOK,nop,nop,nop,nop,timestamp 0 0>
20:20:03.932114 IP 192.168.1.100.smtp > 192.168.1.121.65517: S 
760749685:760749685(0) ack 1411259276 win 32768 <mss 1460,nop,wscale 
0,nop,nop,timestamp 0 0,sackOK,nop,nop>
20:20:03.932136 IP 192.168.1.100.smtp > 192.168.1.121.65517: S 
760749685:760749685(0) ack 1411259276 win 32768 <mss 1460,nop,wscale 
0,nop,nop,timestamp 0 0,sackOK,nop,nop>
20:20:06.920894 IP 192.168.1.100.smtp > 192.168.1.121.65517: S 
760749685:760749685(0) ack 1411259276 win 32768 <mss 1460,nop,wscale 
0,nop,nop,timestamp 6 0,sackOK,nop,nop>
20:20:06.921531 IP 192.168.1.100.smtp > 192.168.1.121.65517: S 
760749685:760749685(0) ack 1411259276 win 32768 <mss 1460,nop,wscale 
0,nop,nop,timestamp 6 0,sackOK,nop,nop>


Could you please advise?


Best regards
--
Matteo Beccati
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