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Request: make tunnel routable (or explain why for this newbie)
![[us]](/s/countries/us.gif) Shadow Hawkins on Thursday, 30 June 2011 06:08:03
Maybe I'm missing something, being new to IP6, but although the tunnel was granted and came up quickly, I apparently get only 1 IP6 address. Our gateway server can reach the IP6verse, but it doesn't have much beyond ping6 to play with. To get more, I apparently have to request a subnet to get routed through the tunnel. But I'm not allowed to do that for a week (provided the tunnel doesn't go down). I suppose I could try another TB, like Hurricane Electric, but they only promise "you can route a subnet after your tunnel is up", which I suppose could involve a similar time delay before you can actually *use* the tunnel.
a) Why waste an entire /64 on a single tunnel? I'm just trying to understand the philosophy. I know 2^128 is really really big, but I kind of expected each Pop to get a /64 (which is what I read that ISP customers will get), and the Pop would use at least a /96 to provide for up to 2^32 tunnels.
b) Ok, so a /64 is assigned to each tunnel. Why not reserve a small part of that, say a /120 for the actual tunnel, and automatically route the rest through the tunnel?
Request: make tunnel routable (or explain why for this newbie)
But I'm not allowed to do that for a week (provided the tunnel doesn't go down).
See the credits FAQ for various options of getting enough credits to directly request a subnet.
a) Why waste an entire /64 on a single tunnel?
It is not 'wasted'. A tunnel is a link, and a link in IPv6 is a /64. As this is a point to point link only 2 IP addresses are on that link though, and we chose for ease of configuration that these are ::1 (PoP) and ::2 (user). In theory though we could have that link run over a native ethernet connection and thus upgrade the user to native IPv6 without them renumbering.
Each PoP gets at least a /40 btw, see PoP prefixes for the full list.
And don't you think 2^32 tunnels would be a bit much!? Having one /48 dedicated to tunnels and runing
b) Ok, so a /64 is assigned to each tunnel. Why not reserve a small part of that say a /120 for the actual tunnel, and automatically route the rest through the tunnel?
How would you set up the routes for that? It would become quite messy, thus that won't work.
We are currently testing the new sixxsd though which will actually use the top-part of the tunnel /48 as subnets that will be routed to the endpoint. Hopefully, after some more testing we will be upgrading PoPs as early as next week. And then folks won't need a subnet anymore in most cases as they will have a /64 for their tunnel and a /64 routed behind that for at least one ethernet interface.
Request: make tunnel routable (or explain why for this newbie)
Shadow Hawkins on Sunday, 03 July 2011 01:20:12
ifconfig Tnnnnn inet6 add 2001:xxxx:xxxx:xxxx::1/120
route -A inet6 2001:xxxx:xxxx:xxxx::/64 gw 2001:xxxx:xxxx:xxxx::2
The most specific route is preferred, so the /120 gets the packets to
the tunnel endpoint.
I've noticed other setups that assign a unique local (fdxx:xxxx... ) address
to the tunnel and endpoints, and then route a global /64 over it.
Request: make tunnel routable (or explain why for this newbie)
A /120 is not a proper link. And we are not going to use ULA as that will make debugging impossible, traceroutes will then become unreadable.
Request: make tunnel routable (or explain why for this newbie)
Shadow Hawkins on Wednesday, 13 July 2011 15:43:24
Ok, I understand the problem with ULA and debugging - thanks for the lesson. Could you also explain further about the /120 and why it is not a "proper link"?
Next attempt (to trisect the angle perhaps? :-) ):
ifconfig T1234 inet6 add 2001:abcd:1234::1 # tunnel
# a /64 subnet
route -A inet6 add 2001:abcd:1234:8888::/64 gw 2001:abcd:1234::2 dev T1234
# a /52 subnet
route -A inet6 add 2001:abcd:1234:1000::/52 gw 2001:abcd:1234::2 dev T1234
Request: make tunnel routable (or explain why for this newbie)
A /64 is the default as defined by the IETF that belongs on a single link.
And are not going to subnet a /64, there is more than enough space. You might want to peek at the news page for a different angle which solves the problem that you probably have.
Request: make tunnel routable (or explain why for this newbie)
Shadow Hawkins on Thursday, 30 June 2011 19:40:36
Ok, so I enabled 6to4, and that gives me a routable subnet on the LAN. That may be a better solution while waiting for our ISP to offer native IP6. I think I'll change my sixxs tunnel to my home network, which is on a dynamic public IP (cable). 6to4 seems to be a no brainer for a static IPv4 IP, but a tunnel is required to deal with dynamic IPs.
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on Thursday, 30 June 2011 10:46:33
Posting is only allowed when you are