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How many Tunnels [Re: Re: pTLA request]
Yiorgos Adamopoulos <[email protected]> writes:
> I think they should be assigned the pTLA. But, just like in our
> case (GRNET, 3FFE:2D00::), they should open more tunnels the just
> with SWITCH and SURFNET.
Yiorgos raised an interesting point here: How many tunnels should
pTLA/transit sites have to other sites.
There seems to be a tendency to build a full mesh between backbone
sites. I think this is very undesirable, because it makes the 6bone
less realistic as a prototype for routing on a global IPv6 network:
* The diameter of the network is kept artificially small.
* Abundance of tunnels introduces an unrealistic level of redundancy,
which reduces the pressure on sites to fix routing problems to a
* Some "single hops" over the 6bone represent many many hops over the
IPv4 Internet, sometimes including congested subpaths. Those
"shortcuts" attract transit traffic that could use a different path
consisting of several hops between 6bone neighbors that are actually
close to each other in the IPv4 Internet topology. This has a bad
impact on global 6bone connectivity.
Personally I would prefer the 6bone topology to resemble the IPv4
topology closer than is the case today. SWITCH's policy as a pTLA has
been to set up tunnels to other networks that we either peer with or
that we have good connectivity with. In particular, we try to avoid
the "shortcuts" I mentioned above, as well as links that regularly
Is there any opinion on mentioning these problems in the "6bone
Routing Practice" I-D, not as a recommendation but as a problem
Personally, I find BME-FSZ's connectivity quite sufficient - SURFNET
and SWITCH are both connected to Hungary over few hops the TEN-34
Simon Leinen [email protected]