Is anyone using FC5 Xen with an FC5 guest, where the Dom0 has two ethernet devices (succesfully)? My system has eth0 as a 192.168.2.x network, eth1 as my static Internet address, and iptables NAT between them. All real machines on my home network can get out just fine. My guest VM, also a 192.168.2.x address, is able to reach other machines on my internal network without problem, but trying to access the internet doesn't work. At first I thought it was an iptables configuration issue on the Dom0 machine, but I don't think so anymore. As a test, I inserted at the top of every table a rule to emit a log message when any machine on my net tried to access a specific remote host; performing a wget command in the guest VM shows my outbound SYN, shows an incoming SYN+ACK from the remote host (so outbound masquarading must be working?) and an outbound ACK (so incoming demasquarading must be working?)... I never receive another packet from the remote host (until quite a while later, when I receive FIN). If I try the same exercise with a real host on my network, I get a normal data stream in/out. Also, traceroute from the guest VM doesn't work exactly as I would expect. I would expect the results of one to be quite similar to those from my Dom0 machine, but consistantly I am missing responses along the path. For example: >From dom0: [root@heilpern ~]# traceroute www.yahoo.com traceroute to www.yahoo.com (216.109.117.106), 30 hops max, 40 byte packets 1 [my cable modem] 2 10.106.32.1 (10.106.32.1) 8.279 ms 11.786 ms * 3 * * * 4 * * * 5 * * * 6 * * * 7 ae-0-0.bbr2.Washington1.Level3.net (4.68.128.210) 45.855 ms * * 8 ae-21-54.car1.Washington1.Level3.net (4.68.121.114) 35.593 ms ae-21-56.car1.Washington1.Level3.net (4.68.121.178) 35.382 ms 41.539 ms 9 4.79.228.2 (4.79.228.2) 40.073 ms 39.931 ms * 10 * * * 11 * * * 12 * p21.www.dcn.yahoo.com (216.109.117.106) 35.227 ms * >From the guest VM: [root@testvm ~]# traceroute www.yahoo.com traceroute to www.yahoo.com (216.109.117.106), 30 hops max, 40 byte packets 1 192.168.2.1 (192.168.2.1) 0.000 ms 0.000 ms 0.000 ms 2 [my cable modem] 3 10.106.32.1 (10.106.32.1) 9.910 ms 13.919 ms * 4 * * * 5 * * * 6 * * * 7 * * * 8 ae-0-0.bbr2.Washington1.Level3.net (4.68.128.210) 48.307 ms * * 9 ae-11-51.car1.Washington1.Level3.net (4.68.121.18) 37.938 ms 42.377 ms ae-21-54.car1.Washington1.Level3.net (4.68.121.114) 43.048 ms 10 4.79.228.2 (4.79.228.2) 45.568 ms 43.918 ms * 11 * * * 12 * * * 13 * * * 14 * * * 15 * * * 16 * * * 17 * * * 18 * * * 19 * * * 20 * * * 21 * * * 22 * * * 23 * * * 24 * * * 25 * * * 26 * * * 27 * * * 28 * * * 29 * * * 30 * * * [root@testvm ~]# This is pretty repeatable. Any thoughts? Here are my Dom0 configurations: [root@heilpern ~]# brctl show bridge name bridge id STP enabled interfaces xenbr0 8000.feffffffffff no peth0 vif0.0 vif2.0 [root@heilpern ~]# ifconfig eth0 eth0 Link encap:Ethernet HWaddr 00:10:DC:F2:70:17 inet addr:192.168.2.1 Bcast:192.168.2.255 Mask:255.255.255.0 inet6 addr: fe80::210:dcff:fef2:7017/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:733780 errors:0 dropped:0 overruns:0 frame:0 TX packets:822036 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:87799449 (83.7 MiB) TX bytes:207088442 (197.4 MiB) [root@heilpern ~]# ifconfig eth1 eth1 Link encap:Ethernet HWaddr 00:90:47:03:B8:63 inet addr:[my IP] Bcast:[my BCAST IP] Mask:255.255.255.252 inet6 addr: fe80::290:47ff:fe03:b863/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:829216 errors:0 dropped:0 overruns:0 frame:0 TX packets:556902 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:169446616 (161.5 MiB) TX bytes:85050877 (81.1 MiB) Interrupt:18 [root@heilpern ~]# iptables -t nat -L Chain PREROUTING (policy ACCEPT) target prot opt source destination Chain POSTROUTING (policy ACCEPT) target prot opt source destination MASQUERADE all -- anywhere anywhere Chain OUTPUT (policy ACCEPT) target prot opt source destination (temporary wide-open rules): [root@heilpern ~]# iptables -L Chain INPUT (policy ACCEPT) target prot opt source destination Chain FORWARD (policy ACCEPT) target prot opt source destination Chain OUTPUT (policy ACCEPT) target prot opt source destination Chain INBOUND (0 references) target prot opt source destination Chain LOG_FILTER (0 references) target prot opt source destination Chain LSI (0 references) target prot opt source destination Chain LSO (0 references) target prot opt source destination Chain OUTBOUND (0 references) target prot opt source destination Thanks in advance... Mark