Results 1 to 3 of 3

Thread: Ubuntu server as an IPv6 gateway

  1. #1
    Join Date
    Oct 2008
    Beans
    3

    Unhappy Ubuntu server as an IPv6 gateway

    Hi!
    I'm having a bit of a troublesome situation with Ubuntu
    servers and IPv6.
    The situation is this:

    My ISP is providing us with a block of IPv6 addresses.
    All traffic coming to this IPv6 network block is routed to me via a GRE tunnel.
    The GRE tunnel between me and my ISP is set up with these commands:
    ip tunnel add ipv6tunnel mode gre remote <isp tunnel endpoint IPv4> local <my local tunnel endpoint IPv4> ttl 255
    ip link set ipv6tunnel up
    ip addr add 2001:a:b::2/64 dev ipv6tunnel #ipv6 address from the address block ISP has provided us
    ip -6 route add 2001::/3 dev ipv6tunnel

    So this machine has a public IPv4 address (the tunnel endpoint IPv4) and an IPv6 network address from the
    ISPs address space (2001:a:b::2). I can use both of these addresses to connecting to and from this machine and everything works fine.


    However this machine is acting as a bridge. The line from my ISP comes to eth0 of this machine and it's bridged with interface eth1
    that's connected to a switch.
    In this switch I have other Ubuntu machines that I need to configure so that they too would have
    IPv6-addresses from that address block my ISP has provided. Their IPv6-traffic would then
    go to this machine which is running the GRE tunnel and get routed through this tunnel.

    I'm really not an experienced network or linux guru and I don't really know what
    steps would I need to take on this gateway machine that already has working IPv6, and on those
    other machines, in order to get this to work.

    I've tried to set up some kind of routing on one of these machines like this:
    in /etc/network/interfaces:

    iface eth0 inet6 static
    address 2001:a:b::3 #another IPv6 address from nyt ISPs block
    netmask 64
    pre-up modprobe ipv6
    up route -A inet6 add default gw ::1.2.3.4 #here the gw address is the IPv4 address of my GRE machines public IPv4 address

    Now if I try to ping my GRE machines IPv6 address I get only this:

    ping6 2001:a:b::2
    PING 2001:a:b::2(2001:a:b::2) 56 data bytes
    From 2001:a:b::3 icmp_seq=1 Destination unreachable: Address unreachable
    From 2001:a:b::3 icmp_seq=2 Destination unreachable: Address unreachable

    If I take tcpdump -n -i br0 icmp6 on my GRE tunneling machine, I can see queries that the pinging machine is sending but my gateway machine obviously doesn't respond?
    tcpdump -n -i br0 icmp6
    tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
    listening on br0, link-type EN10MB (Ethernet), capture size 96 bytes
    15:43:18.807910 IP6 2001:a:b::3 > ff02::1:ff00:7: ICMP6, neighbor solicitation, who has 2001:a:b::2, length 32
    15:43:19.807875 IP6 2001:a:b::3 > ff02::1:ff00:7: ICMP6, neighbor solicitation, who has 2001:a:b::2, length 32

    Could someone point me out to the right direction here? What am I doing wrong (I'm afraid there might be plenty of things...)?

  2. #2
    Join Date
    Oct 2006
    Beans
    457

    Re: Ubuntu server as an IPv6 gateway

    I know nothing about GRE tunnelling, and am new to ipv6 but just covered ipv6 in ICND2 today. Searching on "GRE tunnel +ipv6", this comes up first.
    http://lartc.org/howto/lartc.tunnel.gre.html
    which says up top:
    In Linux, you'll need the ip_gre.o module.

    I hope this gives you some direction and/or help.
    Google is your friend...Ubuntu 9.10 Karmic Koala 64 bit Foxconn WinFast 761GXK8MC-S AMD 64 3200+ 1 GB DDR2, nVidia 8500GT
    Production platform - Intrepid 64 bit 8.10 ASRock ALiveNF6P Phenom 9600 2GB DDR2 GeForce6x and Beryl/Compiz/Desktop Effects

  3. #3
    Join Date
    Oct 2008
    Beans
    3

    Re: Ubuntu server as an IPv6 gateway

    Quote Originally Posted by jhenager View Post
    I know nothing about GRE tunnelling, and am new to ipv6 but just covered ipv6 in ICND2 today. Searching on "GRE tunnel +ipv6", this comes up first.
    http://lartc.org/howto/lartc.tunnel.gre.html
    which says up top:
    In Linux, you'll need the ip_gre.o module.

    I hope this gives you some direction and/or help.
    Thanks, I already studied that site when I was going through with GRE tunneling with my ISP.

    I believe that's not the problem anymore as the IPv6 traffic reaches my tunneling machine. Now it's just the question of how to get this tunneling server distribute IPv6 addresses to other machines in my switch and route traffic to them. I'm trying to install the dhcpv6-project server and clients now to see if they can offer a solution. Let's see how it goes.

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •