Datacenter

Ease out your IPv6 gateway!

One of very cool features of IPv6 is link-local address which stays local to a given link. For this fe80::/10 is reserved. A /10 is a huge amount of address space in IPv6 (and in IPv4 too :) ). This means from fe80:0000:0000:0000:0000:0000:0000:0000 to febf:ffff:ffff:ffff:ffff:ffff:ffff:ffff.

Since by design link-local address stays local, the address configured on the upstream/gateway router can be kept same for ease of use and comfort. This wasn’t the case of IPv4 where each VLAN/layer 2 domain had it’s own gateway.   So e.g if you have two VLANs or interfaces say: Gi1/0 and Gi2/0. You decide to use 10.100.100.0/30 on Gi1/0 and 10.100.100.4/30 on Gi2/0.

Welcome Amazon AWS AS16509 to India!

Today I spotted some routes from Amazon AWS Cloud services -  AS16509 in Indian tables. AS16509 was originating prefixes while sitting in downstream of Tata-VSNL AS4755 and Reliance AS18101. I almost missed Amazon AWS's announcement on their blog about Indian PoPs for their DNS service - Route53 and CDN service - Cloudfront.

New PoP’s of Amazon in India are at Mumbai and Chennai and I see pretty much consistent BGP announcements to Tata and Reliance from these locations. Prefixes I have seen so far: