Sun, 06 Feb 2011 11:54:34 +0100 OoO En cette matinée ensoleillée du dimanche 06 février 2011, vers 09:15, je disais: > I will try to reproduce the problem on a small virtual machine. I have reproduced my problem in a virtual machine. I can provide the virtual machine image if needed (Virtual Box). I have installed a stock Lenny. Update : after upgrading to squeeze (2.6.32 with vserver 2.3.0.36.29), the problem has disappeared. I keep the remaining of my post intact just for information. debian:~# uname -a Linux debian 2.6.26-2-vserver-amd64 #1 SMP Tue Jan 25 06:09:17 UTC 2011 x86 64 GNU/Linux This 2.3.0.35 vserver with bindmount-dev patch and a very small patch replacing use of FUNC by func . debian:~# ip a l 1: lo: <LOOPBACK,UP,LOWER UP> mtu 16436 qdisc noqueue state UNKNOWN link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo inet6 ::1/128 scope host valid lft forever preferred lft forever 2: eth0: <BROADCAST,MULTICAST,UP,LOWER UP> mtu 1500 qdisc pfifo fast state UP qlen 1000 link/ether 08:00:27:db:ad:16 brd ff:ff:ff:ff:ff:ff inet 192.168.116.18/24 brd 192.168.116.255 scope global eth0 inet6 2001:db8:2::3/64 scope global valid lft forever preferred lft forever inet6 2001:db8:2::2/64 scope global valid lft forever preferred lft forever inet6 2001:db8:2::1/64 scope global valid lft forever preferred lft forever inet6 fe80::a00:27ff:fedb:ad16/64 scope link valid lft forever preferred lft forever 3: dummy0: <BROADCAST,NOARP,UP,LOWER UP> mtu 1500 qdisc noqueue state UNKNOWN link/ether 1a:52:bf:9f:6a:02 brd ff:ff:ff:ff:ff:ff inet 192.168.1.1/24 brd 192.168.1.255 scope global dummy0 inet 192.168.1.2/24 brd 192.168.1.255 scope global secondary dummy0 inet 192.168.1.3/24 brd 192.168.1.255 scope global secondary dummy0 inet6 fe80::1852:bfff:fe9f:6a02/64 scope link valid lft forever preferred lft forever debian:~# ip -6 route show 2001:db8:1::1 dev eth0 metric 1024 mtu 1500 advmss 1440 hoplimit 4294967295 2001:db8:2::/64 dev eth0 metric 256 mtu 1500 advmss 1440 hoplimit 4294967295 fe80::/64 dev eth0 metric 256 mtu 1500 advmss 1440 hoplimit 4294967295 fe80::/64 dev dummy0 metric 256 mtu 1500 advmss 1440 hoplimit 4294967295 default via 2001:db8:1::1 dev eth0 metric 1024 mtu 1500 advmss 1440 hoplimit 4294967295 My /etc/network/interfaces : # The loopback network interface auto lo iface lo inet loopback # The primary network interface auto eth0 iface eth0 inet dhcp iface eth0 inet6 static address 2001:db8:2::1 netmask 64 up ip -6 route add 2001:db8:1::1 dev eth0 up ip route add default via 2001:db8:1::1 auto dummy0 iface dummy0 inet static address 192.168.1.1 netmask 255.255.255.0 up iptables -t nat -A POSTROUTING -s 192.168.1.0/16 -o eth0 -j MASQUERADE I have another host with 2001:db8:1::1/59 address. From host, I can ping this IP. I have setup two vserver : /etc/vservers/vserver1/interfaces/0/dev : dummy0 /etc/vservers/vserver1/interfaces/0/ip : 192.168.1.2 /etc/vservers/vserver1/interfaces/0/prefix : 24 /etc/vservers/vserver1/interfaces/1/dev : eth0 /etc/vservers/vserver1/interfaces/1/ip : 2001:db8:2::2 /etc/vservers/vserver1/interfaces/1/prefix : 64 /etc/vservers/vserver2/interfaces/0/dev : dummy0 /etc/vservers/vserver2/interfaces/0/ip : 192.168.1.3 /etc/vservers/vserver2/interfaces/0/prefix : 24 /etc/vservers/vserver2/interfaces/1/dev : eth0 /etc/vservers/vserver2/interfaces/1/ip : 2001:db8:2::3 /etc/vservers/vserver2/interfaces/1/prefix : 64 On vserver1, if I do : vserver1:/# nc6 2a00:1450:8002::67 80 I get on tcpdump : 11:18:31.985791 IP6 2001:db8:2::3.38081 > 2a00:1450:8002::67.80: Flags [S], seq 3421204451, win 5760, options [mss 1440,sackOK,TS val 221191 ecr 0,nop,wscale 5], length 0 But: vserver1:/# ip -6 a l 2: eth0: <BROADCAST,MULTICAST,UP,LOWER UP> mtu 1500 qlen 1000 inet6 2001:db8:2::2/64 scope global valid lft forever preferred lft forever -- BOFH excuse #19: floating point processor overflow