Comcast's 6to4 Relays

Bhoomi Jain bhoomij at
Wed Apr 20 02:26:44 UTC 2011

Mr. John,

I thank you for asking the advice of the community.

As our colleagues suggest, having 6to4 relays inside the network helps to reduce the latency.  Opening up your generous services to a larger Internet community by advertising the BGP prefix outside the network could have extreme and unintended consequences.

To give you an idea, a lot of the Internet in India depends on the service of the Tata companies, with international routing coming from Tata Communications AS 6453.  Announcing to 6453 as a customer, I would worry about its treatment as BGP best-path, in place of closer 6to4 relays.  As you understand, these circuits are very far away, and also very full.  This is not something I would recommend.

Bhoomi Jain

At 19 Apr 2011 22:51:24 +0200 (CEST) from "Brzozowski, John" <John_Brzozowski at>:

>Since deploying our 6to4 relays, Comcast has observed a substantial
>reduction in the latency associated with the use of 6to4. As such we are
>contemplating further opening our relays for use by others. The
>availability of our 6to4 relays should improve the experience of others
>using 6to4 as a means to access content and services over IPv6.
>We have been open about our IPv6 activities and wanted to follow suit by
>reaching out to the community and soliciting feedback before moving
>forward. As always we wish to continue to advocate and support the
>universal deployment of IPv6.
>Please send any comments or questions to the list or if you wish to me
>John Jason Brzozowski
>Comcast Cable
>e) mailto:[email protected][]
>o) 609-377-6594
>m) 484-962-0060
>w) []

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