MTU handling in 6RD deployments

Anfinsen, Ragnar Ragnar.Anfinsen at
Tue Jan 7 20:00:45 CET 2014

On 07.01.14 17:10, "Jean-Francois.TremblayING at"
<Jean-Francois.TremblayING at> wrote:

>> How many users use your 6rd BR (pr. BR if many)?
>50k on a pair of ASR1002-5G, but the second is mostly idle.

We have about 2K for the time being as we do opt-in.

>> How does the rate-limiting (drops) numbers look at your side?
>Actually, it's quite high (over 50%). I gave up on reaching zero here.
>The nature of the traffic seems to be bursty enough that getting to zero
>will be nearly impossible.

As of right now, we have a IPv6 ICMP packet drop of 0,09%. If you want to
hit the 0% mark, you must disable rate-limiting. However, seen from an
operational point of view turning off ICMP rate-limiting makes your 6rd BR
vulnerable for ICMP ping attacks.


More information about the ipv6-ops mailing list