Colleagues, I'd like to hear how you others deal with those peers, whose AS-sets expands to way too large prefix-lists and/or as-paths. There are some networks that only ever add members to their AS-sets, but never remove. I have some deep frustration at (automatically) configuring our routers with prefix-lists or as-path filters that are magnitude or two as big as the specific peer's real advertised route count. Modern router platforms can quite easily handle large configs, but gigantic as-path filters seem to cause unnecessary increase in commit times at least in our JunOS platforms. The penalty feels higher than the reward.
After all, if the peer's AS-set expands to cover big portion of the entire ASN space, I'm begin to ponder whether it would make more sense to drop IRR based as-path filtering altogether for those peers and use e.g. some sort of generalized peerlock filter? Are there any others as frustrated as I am and how have you solved this issue? I will appreciate constructive feedback. -Antti
