nanog mailing list archives
Re: aggregate6 - a fast versatile prefix list compressor
From: Julien Goodwin <nanog () studio442 com au>
Date: Fri, 1 Dec 2017 21:09:38 +1100
On 01/12/17 07:27, Job Snijders wrote:
Someone suggested I should clarify what 'aggregate6' actually does :-) aggregate6 takes a list of IPv4 and/or IPv6 prefixes in conventional format, and performs two optimisations to attempt to reduce the length of the prefix list. The first optimisation is to remove any supplied prefixes which are superfluous because they are already included in another supplied prefix. For example, 2001:67c:208c:10::/64 would be removed if 2001:67c:208c::/48 was also supplied. The second optimisation identifies adjacent prefixes that can be combined under a single, shorter-length prefix. For example, 2001:67c:208c::/48 and 2001:67c:208d::/48 can be combined into the single prefix 2001:67c:208c::/47. As an IPv4 exampl: 10.0.0.0/24 and 10.0.1.0/24 can be joined into 10.0.0.0/23.
Will it catch cases like: 10.0.0.0/24 10.0.1.0/24 10.0.2.0/23 -> 10.0.0.0/22
The above two optimalisations are useful in context of firewall rule generation or generation of BGP prefix-list filters.
Or being a nice citizen and rationalising your announcements.
Current thread:
- aggregate6 - a fast versatile prefix list compressor Job Snijders (Dec 01)
- Re: aggregate6 - a fast versatile prefix list compressor Job Snijders (Dec 01)
- Re: aggregate6 - a fast versatile prefix list compressor Julien Goodwin (Dec 01)
- Re: aggregate6 - a fast versatile prefix list compressor Job Snijders (Dec 01)
- Re: aggregate6 - a fast versatile prefix list compressor Elmar K. Bins (Dec 01)
- Re: aggregate6 - a fast versatile prefix list compressor Steve Atkins (Dec 01)
- Re: aggregate6 - a fast versatile prefix list compressor Julien Goodwin (Dec 01)
- Re: aggregate6 - a fast versatile prefix list compressor Job Snijders (Dec 01)
- Re: aggregate6 - a fast versatile prefix list compressor Aliaksei Sheshka (Dec 01)
- Re: aggregate6 - a fast versatile prefix list compressor Job Snijders (Dec 01)