Drop those stupid addresses smaller than /48

Two years ago, when I looked at IPv6 address announcements, I saw that our fellow Singapore major “traffic light” (red for Singtel, yellow for Mobile One, green for Starhub) Internet Service Providers (ISPs) announced lots of /64 subnets. This is against the RFC3177 which states that the smallest announcement should be /48. It is very easy for people to flood and bloat the IPv6 table if they announce a shit ton of /64 addresses. And I hate that memory eating table; you should too.

Today, I took a look again. The situation has slightly improved.

It seems like Singtel has stopped announcing /64 on their major AS networks, kudos to them for finally doing some things properly. Whilst the other two has not changed, they were still announcing tons of /64s.

Since the situation isn’t improving much, I would like to make an open plea to all AS peers of these ISPs to implement ACLs and drop all IPv6 announcements that are smaller than /48. Even if you’re not one of the peers, you should implement such an ACL too.

Let’s make the Internet a better place for everyone.

Author: Woo Huiren

Currently a student at National University of Singapore. I contribute to opensource projects - primarily PHP and Angular related. I write about PCF and PWS related stuff too.

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