AW: /27 the new /24

Jürgen Jaritsch jj at
Fri Oct 2 14:45:29 UTC 2015


this would at least help to get rid of many old routing engines around the world :) ... or people would keep their "learn nothing smaller than /24" filters in place. Also an option - but not for companies who act as an IP transit provider.

best regards

Jürgen Jaritsch
Head of Network & Infrastructure

ANEXIA Internetdienstleistungs GmbH

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-----Ursprüngliche Nachricht-----
Von: NANOG [mailto:nanog-bounces at] Im Auftrag von Justin Wilson - MTIN
Gesendet: Freitag, 02. Oktober 2015 16:32
Betreff: /27 the new /24

I was in a discussion the other day and several Tier2 providers were talking about the idea of adjusting their BGP filters to accept prefixes smaller than a /24.  A few were saying they thought about going down to as small as a /27.  This was mainly due to more networks coming online and not having even a /24 of IPv4 space.  The first argument is against this is the potential bloat the global routing table could have.  Many folks have worked hard for years to summarize and such. others were saying they would do a /26 or bigger.  

However, what do we do about the new networks which want to do BGP but only can get small allocations from someone (either a RIR or one of their upstreams)?

Just throwing that out there. Seems like an interesting discussion.

Justin Wilson
j2sw at

--- Owner/CEO
xISP Solutions- Consulting – Data Centers - Bandwidth  COO/Chairman
Internet Exchange - Peering - Distributed Fabric

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