[c-nsp] BNG IPv6 Prefix Delegation Accounting

[Sebastian Graf]

Hi,

we are currently working on providing IPv6 to residential customers. The BNG used is a Cisco ASR1k running 15.2(2)S1. While most part seem to work out nicely, there is an issue with Adress Accounting and DHCPv6 Prefix Delegation.

It seems that the Accounting Start messages generally do not include the IPv6 Prefix assigned via Prefix Delegation. Only the link local and SLAAC addresses are provided. I guess this is because the PPP session establishment is decoupled from the address assignment with IPv6.

This is no big deal if I provide the prefix from the radius (as I can log it there), however if I tell the ASR to assign an address from a local pool (using Cisco-AVpair = "ipv6:delegated-ipv6-pool=<POOL-NAME>"), there seems to be no way to track which prefix was assigned to which subscriber (which is needed for legal purposes).

Did anybody came across a similar situation or knows if there is a way to log these assignments? Or is the only option in this case to move the pool management to an external server and log it there?

kind regards
Sebastian