Hurricane Electric's IPv6 Tunnel Broker Forums

Advanced search  


Welcome to Hurricane Electric's forums!

Author Topic: Routing and prefixes  (Read 5050 times)


  • readonly_member
  • Newbie
  • *
  • Posts: 1
Routing and prefixes
« on: March 31, 2009, 08:49:13 AM »

I know this has probably been asked many times before -- and I'm getting there honest!

I've got my tunnel up and I can successfully ping6 the far end. I'm using a /64 routed space.
I've also got local machines pinging the router on their on /80 space.  (Right?)  It seemed to me that if I was offered a /64 of
a:b:c:d::/64, I could just use a:b:c:d:1::/80 for internal nodes.  I also gave this number to Radvd.

Everything works except when I try to leave the subnet.  In IPv4, it's a default route and IP forwarding problem.  Here, I get address out of scope on a ping6.  My thoughts, such as they are :-) were that:

If the local nodes were ::/80, and they had a default route ::/0 to the router it woudl pass things on to the tunnel.
On the way back, given everything is global, traffic should flow back to the ::/80.

It doesnt.  What have I missed?



  • Newbie
  • *
  • Posts: 31
Re: Routing and prefixes
« Reply #1 on: March 31, 2009, 09:41:09 AM »

"Normal" setups use /64s as subnets. Especially autoconfiguration requires a /64.

If you only got one routed /64 and want to use autoconfiguration, you can only use one subnet.

FYI, RFC 1972 was obsoleted by RFC 2464. (Therefore 64 bit host addresses are required for autoconfiguration on ethernet.)
« Last Edit: March 31, 2009, 09:45:04 AM by kristiankrohn »


  • Sr. Member
  • ****
  • Posts: 272
    • aRDy Music
Re: Routing and prefixes
« Reply #2 on: March 31, 2009, 01:01:14 PM »

Is ipv6 forwarding enabled on the gateway machine?
Since radvd requires /64, are the LAN machines actually GETTING an IP in your /80?