SixXS::Sunset 2017-06-06

Can tunnel rDNS be done even with sixxsd v3?
[dk] Shadow Hawkins on Monday, 31 October 2011 18:30:53
According to the news item about sixxsd v4, one of the new features is the ability to change rDNS for the tunnel /64, just like for an assigned /48. This is great, as it removes another reason for wasting a /48 when only one or a few computers are really connected to a tunnel. So as the subject says: Is this feature (which isn't really part of sixxsd I guess) also available for PoPs that still run sixxsd v3?
Can tunnel rDNS be done even with sixxsd v3?
[ch] Jeroen Massar SixXS Staff on Monday, 31 October 2011 19:01:41
one of the new features is the ability to change rDNS for the tunnel /64,
Nope, you misunderstood (or I wrote it wrong ;) In v4 one gets a /64 tunnel (<prefix>::1 == PoP, <prefix>::2 == user) and towards <prefix>::2 is routed automatically also a separate /64. That 'default routed /64' is a normal subnet from the view of the system and thus can also get reverse DNS servers assigned. It is thus not the tunnel IPs, it is a separate /64.
This is great, as it removes another reason for wasting a /48 when only one or a few computers
are really connected to a tunnel.
The whole idea of /48s is 'one size fits all'. The prime reason for adding the default-routed /64 is that people who have CPEs (eg AVM Fritz!Box, Motorola's, etc) only terminate the tunnel and then would need alternate ways of earning credits to actually get a subnet routed to them. The default-routed /64 solves this, as it only gives connectivity, if one needs more one still has to earn those credits.
So as the subject says: Is this feature (which isn't really part of sixxsd I guess) also available for PoPs that still run sixxsd v3?
No, as the separate thing is something that the v4 code does.
Can tunnel rDNS be done even with sixxsd v3?
[dk] Shadow Hawkins on Tuesday, 01 November 2011 16:10:18
Ah sorry, I read it as the tunnel /64 being expanded to route all but <prefix>::1 == <PoP> to the user, so the user can include additional IPs besides <prefix>::2, such as <prefix>::3, <prefix>::4 etc. and/or use routing tools to put a whole network segment at his end. The rDNS part of that feature (ability to change rDNS for the tunnel itself) would probably not have been a part of the sixxsd code itself, hence my question. I have a general feeling that the way IPv6 blocks are currently handed out looks too much like the way IPv4 blocks were handed out in the 1980s, hence my excitement for announcements that show more prudence.
Can tunnel rDNS be done even with sixxsd v3?
[ch] Jeroen Massar SixXS Staff on Tuesday, 01 November 2011 16:17:02
Your feeling is unfounded, there are millions of /48s, even if giving every human being and their pets's flees each a /48 we won't have run out of them. Quite a difference with IPv4. 2^48 = 2.81474977 10^14 Heck, you can probably give every cell their own /48 that way. Either way, routing table slots will be full far before one ever will run out of address space. And, currently only 2000::/3 is being used, if that ever runs out, there are 7 other /3s to do allocation from, and thus a total of 8 tries to get it right, thus not ever in our lifetimes (unless immortality sneaks around the corner)

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