Ipv6 addressing for Core network

Wed Feb 9 06:41:47 UTC 2011

> I am looking for the recommendation for core interfaces IP addressing
> schema
> for Ipv6. Some different views are (PE- P - PE, point to point link)
as
> below -
> 
> 1-  Use Public Ipv6 with /122 and do not advertise to Internet
> 2-  Use Public Ipv6 with /127 and do not advertise to Internet
> 3-  Use Unique local ipv6 address
> 4- Use Public Ipv6 with /64
> 
> Also I am interested to understand the impact on TCAM ...
> 
> Regards,
> Vikas

I would use a /64 with ND turned off and static neighbors configured.
TCAM impact will depend on vendor.  Some vendors give you the option of
storing the first 64 bits of a V6 IP or the entire address.  Using a /64
means your CAM usage might be less depending on your vendor.

If the addresses on the point-to-point links never accept or source
direct traffic to/from outside your net, you can use whatever you want
on them.  ULA might be ok there.  I am using public IPs but I filter
traffic destined for them at the edge but to each their own choice.  But
if you use ULA you aren't going to be able to ping anything outside your
net if you source the pings from the ULA interface.  Just something to
keep in mind.

What you are asking is a matter of individual preference.