Should be able to specify exact subnet prefixes to ignore

[Morten Brekkevold]

The ipdevpoll subnet prefix plugin takes an option from `ipdevpoll.conf`, a series of prefixes to ignore during collection of port addresses and prefixes.

The prefixes are inclusive, meaning that they will match any address that is equal to, or contained within, the listed prefix. It is used to ignore things like loopback addresses by adding 127.0.0.0/8 to the list.

However, Juniper routers configured in a virtual chassis setup seem to use weirdly huge prefixes for administrative purposes on their interlinks: 128.0.0.0/2. Collecting this prefix will cause NAV to think lots of Juniper routers are L3 neighbors, even though they are not - they only share this absurd prefix.

The prefix cannot be added to the ignore list, since any contained prefix will also be ignored, which means about 25% of the address space available on the IPv4 internet, in this case.

The syntax of this option should be expanded to allow equals matches in addition to the existing "contained within or equals" matches.

[Morten Brekkevold (mbrekkevold)]

fix here: https://nav.uninett.no/hg/stable/rev/767b945aa9c3