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icon5.gif  IPv6 with venet : is it possible ? [message #31324] Tue, 24 June 2008 19:32 Go to next message
Romain Riviere is currently offline  Romain Riviere
Messages: 5
Registered: February 2006
Junior Member
Hello crowd,

The title pretty much sums it up.
I've read multiple posts all over the place. Some of them suggest that IPv6 and venet don't mix, others seem to indicate that it works well.

So far, my own experience has been rather miserable : my VE can ping the host but not the outside world (the host itself is fine).

If you have IPv6 running along with venet, I would love to hear about it. If you know for a fact that it is completely and utterly impossible, I'd be glad if you could share it too Smile

Many thanks and best regards,

Romain
Re: IPv6 with venet : is it possible ? [message #31365 is a reply to message #31324] Wed, 25 June 2008 19:34 Go to previous messageGo to next message
swindmill is currently offline  swindmill
Messages: 57
Registered: April 2007
Member
It would seem as though there is just enough information on the forums and elsewhere to suggest that this should work, but there are also many people experiencing the same issue as the post above.

Can we confirm whether ipv6 should work inside of a CT using venet? If so, is there something we're missing in regards to getting ipv6 to properly route from a CT to the outside?
Re: IPv6 with venet : is it possible ? [message #32037 is a reply to message #31324] Thu, 17 July 2008 17:26 Go to previous messageGo to next message
swindmill is currently offline  swindmill
Messages: 57
Registered: April 2007
Member
On my CentOS 5.2 host nodes I do not see that ipv6 forwarding is enabled by default.

According to this page:

http://pages.citebite.com/y6x6c2h3misp

Linux does not allow you to turn on ipv6 forwarding for a single interface. It must be enabled or disabled globally.

Can you check `cat /proc/sys/net/ipv6/conf/all/forwarding` on your host node and report back?
Re: IPv6 with venet : is it possible ? [message #32039 is a reply to message #32037] Thu, 17 July 2008 17:48 Go to previous messageGo to next message
Romain Riviere is currently offline  Romain Riviere
Messages: 5
Registered: February 2006
Junior Member
I have tested virtually everything, including echo 1 > /proc/sys/net/ipv6/conf/all/forwarding

So far my conclusion is that it is impossible to run IPv6 with venet, or that those who managed to do it won't let others hear about it ...
Re: IPv6 with venet : is it possible ? [message #32126 is a reply to message #31324] Tue, 22 July 2008 09:34 Go to previous messageGo to next message
qermit is currently offline  qermit
Messages: 2
Registered: July 2008
Junior Member
i have similar problem.

IPv6 works good on Hardware Node when i add address to my eth0 device

vpsbox ~ # ping6 ipv6.google.com
PING ipv6.google.com(2001:4860:0:1001::68) 56 data bytes
64 bytes from 2001:4860:0:1001::68: icmp_seq=1 ttl=53 time=85.7 ms
64 bytes from 2001:4860:0:1001::68: icmp_seq=2 ttl=53 time=21.0 ms
64 bytes from 2001:4860:0:1001::68: icmp_seq=3 ttl=53 time=21.0 ms


when i move ip address to dummy0 it works for some time
vpsbox ~ # ip a d  2001:41d0:1:f11c::1/64 dev eth0
vpsbox ~ # ip a a  2001:41d0:1:f11c::1/64 dev dummy0
vpsbox ~ # ping6 ipv6.google.com
PING ipv6.google.com(2001:4860:0:1001::68) 56 data bytes
64 bytes from 2001:4860:0:1001::68: icmp_seq=1 ttl=53 time=21.0 ms
64 bytes from 2001:4860:0:1001::68: icmp_seq=2 ttl=53 time=21.4 ms
64 bytes from 2001:4860:0:1001::68: icmp_seq=3 ttl=53 time=21.4 ms
....
....
....
64 bytes from 2001:4860:0:1001::68: icmp_seq=21 ttl=53 time=21.1 ms
64 bytes from 2001:4860:0:1001::68: icmp_seq=22 ttl=53 time=21.1 ms
64 bytes from 2001:4860:0:1001::68: icmp_seq=23 ttl=53 time=21.0 ms

--- ipv6.google.com ping statistics ---
42 packets transmitted, 23 received, 45% packet loss, time 40996ms
rtt min/avg/max/mdev = 20.925/21.220/21.938/0.239 ms


but, after some time it fails. I did the same thing with ipv6 address assigned to VE

vpsbox ~ # ip a a  2001:41d0:1:f11c::1:1/64 dev eth0
vpsbox ~ # ping6 ipv6.google.com
PING ipv6.google.com(2001:4860:0:1001::68) 56 data bytes
64 bytes from 2001:4860:0:1001::68: icmp_seq=1 ttl=53 time=23.1 ms
64 bytes from 2001:4860:0:1001::68: icmp_seq=2 ttl=53 time=21.6 ms

--- ipv6.google.com ping statistics ---
2 packets transmitted, 2 received, 0% packet loss, time 1000ms
rtt min/avg/max/mdev = 21.627/22.368/23.110/0.756 ms
vpsbox ~ # ip a d 2001:41d0:1:f11c::1:1/64 dev eth0


vpsbox ~ # vzctl enter 777
entered into VE 777
vpsbox:/# ping6 ipv6.google.com
PING ipv6.google.com(2001:4860:0:1001::68) 56 data bytes
64 bytes from 2001:4860:0:1001::68: icmp_seq=1 ttl=52 time=21.1 ms
64 bytes from 2001:4860:0:1001::68: icmp_seq=2 ttl=52 time=21.5 ms
64 bytes from 2001:4860:0:1001::68: icmp_seq=3 ttl=52 time=21.7 ms
64 bytes from 2001:4860:0:1001::68: icmp_seq=4 ttl=52 time=21.1 ms
64 bytes from 2001:4860:0:1001::68: icmp_seq=5 ttl=52 time=21.0 ms
64 bytes from 2001:4860:0:1001::68: icmp_seq=6 ttl=52 time=21.4 ms
64 bytes from 2001:4860:0:1001::68: icmp_seq=7 ttl=52 time=20.8 ms
64 bytes from 2001:4860:0:1001::68: icmp_seq=8 ttl=52 time=21.4 ms
64 bytes from 2001:4860:0:1001::68: icmp_seq=9 ttl=52 time=21.0 ms
64 bytes from 2001:4860:0:1001::68: icmp_seq=10 ttl=52 time=21.9 ms
64 bytes from 2001:4860:0:1001::68: icmp_seq=11 ttl=52 time=21.1 ms
64 bytes from 2001:4860:0:1001::68: icmp_seq=12 ttl=52 time=21.5 ms
64 bytes from 2001:4860:0:1001::68: icmp_seq=13 ttl=52 time=20.9 ms
64 bytes from 2001:4860:0:1001::68: icmp_seq=14 ttl=52 time=21.7 ms
64 bytes from 2001:4860:0:1001::68: icmp_seq=15 ttl=52 time=21.1 ms
64 bytes from 2001:4860:0:1001::68: icmp_seq=16 ttl=52 time=21.1 ms
64 bytes from 2001:4860:0:1001::68: icmp_seq=17 ttl=52 time=21.0 ms
64 bytes from 2001:4860:0:1001::68: icmp_seq=18 ttl=52 time=21.2 ms
64 bytes from 2001:4860:0:1001::68: icmp_seq=19 ttl=52 time=21.3 ms
64 bytes from 2001:4860:0:1001::68: icmp_seq=20 ttl=52 time=21.0 ms
64 bytes from 2001:4860:0:1001::68: icmp_seq=21 ttl=52 time=21.1 ms
64 bytes from 2001:4860:0:1001::68: icmp_seq=22 ttl=52 time=21.4 ms

--- ipv6.google.com ping statistics ---
30 packets transmitted, 22 received, 26% packet loss, time 29000ms
rtt min/avg/max/mdev = 20.852/21.289/21.986/0.323 ms
vpsbox:/#
Re: IPv6 with venet : is it possible ? [message #32190 is a reply to message #31324] Thu, 24 July 2008 18:21 Go to previous messageGo to next message
broquea is currently offline  broquea
Messages: 20
Registered: December 2007
Junior Member
I've got OpenVZ working with native IPv4/IPv6 dual-stack connectivity. I'm certain it can work with a tunnel, but for my experience with this I have native available.

HN runs CentOS 5.1 32bit

ISP provides me with a single /64 allocation and provide gateway on their router. So for this example, I have A:B:C:D::/64, and A:B:C:D::1 is configured on their router, and A:B:C:D::2 is assigned to eth0 on the HN, and A:B:C:D::3+ I can assign to my VEs.

Inside the /etc/sysconfig/network-scripts/ifcfg-eth0:
IPV6INIT=yes
IPV6ADDR=A:B:C:D::2/64
IPV6FORWARDING=yes
IPV6_AUTOCONF=no


Inside /etc/sysconfig/networking:
NETWORKING_IPV6=yes
IPV6_DEFAULTGW=A:B:C:D::1
IPV6_DEFAULTDEV=eth0


Inside /etc/sysctl.conf:
net.ipv6.conf.all.forwarding = 1


Now I've got 2 machines running OpenVZ, one running CentOS 5.0 and the other 5.1. The 5.1 requires after a reboot, to run:
ifconfig venet0 0

Otherwise the VEs with IPv6 configured in them do not start up on that machine. There is probably some fix for this already that I haven't paid attention to, but for now I have modified my system to run that before starting OpenVZ.

I've also seen in the past that under CentOS as the HN, you had to run the following to set the default IPv6 route:
route -A inet6 2000::/3 dev eth0


I found that using the "vzctl set VEID --ipadd" command supports IPv6, and that is how I assign IPv6 addresses to my VEs.

A trick for those who find that their IPv6 times out after, well.... no use, is to configure NTP on the system to use an IPv6 time server. NTP uses very little bandwidth, and checks frequently enough to act as a keepalive.

If this helps, awesome! If you still need help, let me know, and I'll see what I can cook up.
Re: IPv6 with venet : is it possible ? [message #32194 is a reply to message #32190] Fri, 25 July 2008 06:07 Go to previous messageGo to next message
qermit is currently offline  qermit
Messages: 2
Registered: July 2008
Junior Member
i was writing some article on wiki but my browser hangs :/

fist thing is to find default router. I used tcpdump icmp6 and waited for router advertisement packets. (i set ipv6 forwarding first)

Next thing was adding routing entry ip r a ::/0 via <router address> dev <interface>

broquea wrote on Thu, 24 July 2008 14:21

A trick for those who find that their IPv6 times out after, well.... no use, is to configure NTP on the system to use an IPv6 time server. NTP uses very little bandwidth, and checks frequently enough to act as a keepalive.

If this helps, awesome! If you still need help, let me know, and I'll see what I can cook up.


my trick is to send ICMP6 answers for "who has" requests. I use modified parasite6 (thc-ipv6).
vpsbox thc-ipv6-0.7 # ./parasite6 eth0 00:1c:c0:5b:8d:e3
Remember to enable routing (ip_forwarding), you will denial service otherwise!
Started ICMP6 Neighbor Solitication Interceptor (Press Control-C to end) ...
Spoofed packet to fe80:0000:0000:0000:021c:c0ff:fe5b:8de3 as 2001:41d0:0001:f11c:0000:0000:0000:0003
Spoofed packet to fe80:0000:0000:0000:021c:c0ff:fe5b:8de3 as 2001:41d0:0001:f11c:0000:0000:0000:0003
Spoofed packet to fe80:0000:0000:0000:021c:c0ff:fe5b:8de3 as 2001:41d0:0001:f11c:0000:0000:0000:0003
Spoofed packet to fe80:0000:0000:0000:021c:c0ff:fe5b:8de3 as 2001:41d0:0001:f11c:0000:0000:0000:0003


last thing was adding ip address to dummy0 interface or assign to container via --ipadd command.

[Updated on: Fri, 25 July 2008 06:10]

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Re: IPv6 with venet : is it possible ? [message #32229 is a reply to message #32194] Sun, 27 July 2008 16:54 Go to previous messageGo to next message
Romain Riviere is currently offline  Romain Riviere
Messages: 5
Registered: February 2006
Junior Member
Thanks to those who posted.
It seems that IPv6 support is not exactly stable nor well-documented, from what I read here. I'll steer well clear for the time being.

Cheers !
Re: IPv6 with venet : is it possible ? [message #32257 is a reply to message #31324] Tue, 29 July 2008 00:06 Go to previous messageGo to next message
broquea is currently offline  broquea
Messages: 20
Registered: December 2007
Junior Member
FYI, I checked and using a tunnelbroker.net tunnel (and perhaps another brokers might work) I terminate the tunnel on the HN, and then allocate and assign one of the IPv6 addresses out of the routed allocation to the VE.

The VE can ping6/etc out and can be reached. The HN shows up as a hop in the traceroute6 as expected.

So the steps are (and I'll use my tunnels' information)

1) create tunnel interface with commands on the HN:
ifconfig sit0 up
ifconfig sit0 inet6 tunnel ::66.220.18.42
ifconfig sit1 up
ifconfig sit1 inet6 add 2001:470:c:29::2/64
route -A inet6 add ::/0 dev sit1


2) add ipv6 packet forwarding (edit /etc/sysctl.conf for permanent setting):
echo 1 > /proc/sys/net/ipv6/conf/all/forwarding


3) using vzctl, add an IPv6 address out of your routed allocation (lets just say the /64) to the running configuration of a VE:
vzctl set 1001 --ipadd 2001:470:d:29::2 --save


4) test connectivity from inside the VE:
[root@vps0010 ~]# vzctl enter 1001
root@testve:/# traceroute6 -n ipv6.google.com
traceroute to ipv6.google.com (2001:4860:0:2001::68), 30 hops max, 40 byte packets
 1  2001:470:c:29::2  0.091 ms  0.032 ms  0.019 ms
 2  2001:470:0:9d::1  10.832 ms  10.909 ms  10.986 ms
 3  2001:470:0:3a::2  42.412 ms  42.374 ms  42.418 ms
 4  2001:470:0:3b::2  77.478 ms  77.435 ms  77.520 ms
 5  2001:504:0:2:0:1:5169:1  78.224 ms !X  78.172 ms !X  78.382 ms !X


You'll see that the HN will appear as the first hop in the trace, since the /64 is routed behind it. The above commands are issued one after the other, no other magic needed that I can tell. And the reason the trace didn't reach the destination: "!X (communication administratively prohibited)"

[Updated on: Tue, 29 July 2008 07:48]

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Re: IPv6 with venet : is it possible ? [message #32372 is a reply to message #31324] Mon, 04 August 2008 07:56 Go to previous messageGo to next message
broquea is currently offline  broquea
Messages: 20
Registered: December 2007
Junior Member
Working with another OpenVZ user, we noted that he had to use 2000::/3 as their default gateway due to the kernel version.
Re: IPv6 with venet : is it possible ? [message #32373 is a reply to message #32372] Mon, 04 August 2008 08:40 Go to previous message
Romain Riviere is currently offline  Romain Riviere
Messages: 5
Registered: February 2006
Junior Member
I have switched to Linux-VServer in the meantime.

I will try that "ifconfig venet0 0" for completeness's sake, but apart from that, my attempts at using IPv6 were conducted exactly as described elsewhere (IPv6 forwarding, default route via HN etc).

Thanks for your feedback.
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