TCP MSS clamping – what is it and why do we need it?

This (not so very) short video explains what TCP MSS clamping is and why we’re almost forced to use it on xDSL (PPPoE) and tunnel interfaces...

DHCPv6-based address allocation on PPPoE links

Cassidy Larson from InfoWest sent me an interesting challenge: using the sample configurations I provided in the Building Large IPv6 Servi...

More real-life DHCPv6 Prefix Delegation gotchas

The murky details of IPv6 implementations never crop up till you start deploying it (or, as Randy Bush recently wrote : “ it is cheering to ...

IPv6 RADIUS Accounting

Somehow I got involved in an IPv6 RADIUS accounting discussion. This is what I found to work in Cisco IOS release 15.2(4)S: Read more ...

IPv6 over PPPoE works great with IOS XE 3.7

Beatrice Ghorra ( @beebux ) was kind enough to share the results of her IPv6-over-PPPoE tests with me. Short summary: everything works as ...

DHCPv6 Prefix Delegation with Radius works in IOS release 15.1

A while ago I described the pre-standard way Cisco IOS used to get delegated IPv6 prefixes from a RADIUS server . Cisco’s documentation alwa...