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Re: /128 IPv6 prefixs in the wild?


From: Owen DeLong <owen () delong com>
Date: Thu, 15 Dec 2011 02:42:32 -0800

You'll still probably carry the /128 loopbacks in your IGP to deal with your iBGP mesh.

Owen

On Dec 14, 2011, at 9:54 PM, Glen Kent wrote:

Hi,

In the service provider networks, would we usually see a large number
of /128 prefixs in the v6 FIB tables?

In an IP/MPLS world, core routers in the service provider network
learn the /32 loopback IPv4 addresses so that they can establish
BGP/Targetted LDP sessions with those. They then establish LSPs and
VPN tunnels. Since we dont have RSVP for IPv6 and LDP for IPv6 (not
yet RFC) we cannot form MPLS tunnels in a pure IPv6 only network.
GIven this, would v6 routers have large number of /128 prefixes?

What are the scenarios when IPv6 routers would learn a large number of
/128 prefixes?

I would presume that most IPv6 prefixes that the routers have to
install are less than /64, since the latter 64 is the host part. Is
this correct?

Glen



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