Cogent IPv6 [IPv6 newbie alert!]

Daniel Espejel daniel.unam.ipv6 at gmail.com
Thu Jun 9 11:29:17 CDT 2011


As a matter of fact, an IPv6 address has a maximum (but not restricted)
fixed lenght of 64 bits for the network and subnetwork definition, and 64bit
for the interface identifier.

The most left 64 bit in that address contains information about type of
address, scope, network and subnetwork and another "useful" information.

But the fixed restricted lenght is not mandatory, and if locally managed
IPv6 addresses anre created, you can design routes via routing protocols to
follow the same rules as in CIDR.

Best regards xD.

------------------------------
>
> Message: 2
> Date: Wed, 8 Jun 2011 20:58:18 -0500
> From: Kelly Setzer <Kelly.Setzer at wnco.com>
> Subject: RE: Cogent IPv6
> To: "nanog at nanog.org" <nanog at nanog.org>
> Message-ID:
>        <
> FC8ABE0E5D384A489CDB16C4A8EB77839B3E9C6995 at MSMAIL01.LUV.AD.SWACORP.COM>
>
> Content-Type: text/plain;       charset="utf-8"
>
>
> > -----Original Message-----
> > From: ryan at u13.net [mailto:ryan at u13.net]
> > Sent: Wednesday, June 08, 2011 9:19 AM
> > To: nanog at nanog.org
> > Subject: Re: Cogent IPv6
> >
> > On Wed, 8 Jun 2011 09:51:21 -0400, Nick Olsen wrote:
> >
> > > I'm sure someone here is doing IPv6 peering with cogent. We've got a
> > > Gig
> [SNIP]
> > We have separate v4 and v6 sessions with them on the same dual-stack
> > interface (a v4 /29 and v6 /112 on the interface).  One session is
> > between our v4 address and theirs, and carries v4 prefixes only.  Then
> > another session between v6 addresses that carries v6 prefixes only.
>
> IPv6 newbie alert!
>
> I thought the maximum prefix length for IPv6 was 64 bits, so the comment
> about a v6 /112 for peering vexed me.  I have Googled so much that Larry
> Page called me and asked me to stop.
>
> Can someone please point me to a resource that explains how IPv6 subnets
> larger than 64 bits function and how they would typically be used?
>
> thanks,
> Kelly
>
>
-- 
*Daniel Espejel Perez
*



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