Stupid Question maybe?

Wed Dec 19 20:46:43 UTC 2018

> On Dec 19, 2018, at 12:11 , Thomas Bellman <bellman at nsc.liu.se> wrote:
> 
> On 2018-12-19 20:47 MET, valdis.kletnieks at vt.edu wrote:
> 
>> There was indeed a fairly long stretch of time (until the CIDR RFC came out and
>> specifically said it wasn't at all canon) where we didn't have an RFC that
>> specifically said that netmask bits had to be contiguous.
> 
> How did routers select the best (most specific) route for an address?
> If the routing table held both (e.g.) 10.20.30.0/255.255.255.64 and
> 10.20.30.0/255.255.255.32, then 10.20.30.97 would match both, and have
> the same number of matching bits.
> 
> 	/Bellman
> 

The institution of the longest match rule came with the prohibition (deprecation) of
discontiguous net masks.

Owen