nanog mailing list archives
Re: Stupid Question maybe?
From: valdis.kletnieks () vt edu
Date: Wed, 19 Dec 2018 15:50:35 -0500
On Wed, 19 Dec 2018 21:11:39 +0100, Thomas Bellman said:
On 2018-12-19 20:47 MET, valdis.kletnieks () 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.
That didn't stop sites getting creative with it on their internal networks, and I wouldn't be surprised if at least one router (Bay, Proteon, whatever) happened to have an implementation that Just Worked. Remember - there were enough ambiguities and odd implementations that RFC 1122/1123 had to be issued. *Lots* of "How the <expletive> did that ever work?" back in those days - and often the answer was "By accident".
Current thread:
- Re: Stupid Question maybe?, (continued)
- Re: Stupid Question maybe? Adam Atkinson (Dec 20)
- Re: Stupid Question maybe? Smoot Carl-Mitchell (Dec 20)
- Re: Stupid Question maybe? valdis . kletnieks (Dec 19)
- Re: Stupid Question maybe? Thomas Bellman (Dec 19)
- Re: Stupid Question maybe? William Herrin (Dec 19)
- Re: Stupid Question maybe? Thomas Bellman (Dec 19)
- Re: Stupid Question maybe? Owen DeLong (Dec 19)
- RE: Stupid Question maybe? David Edelman (Dec 19)
- Re: Stupid Question maybe? Baldur Norddahl (Dec 19)
- Re: Stupid Question maybe? Joe (Dec 19)
- Re: Stupid Question maybe? valdis . kletnieks (Dec 19)
- Re: Stupid Question maybe? William Allen Simpson (Dec 20)
- Re: Stupid Question maybe? Saku Ytti (Dec 20)
- Re: Stupid Question maybe? Joel Halpern (Dec 20)
- Re: Stupid Question maybe? Tony Finch (Dec 24)
- Re: Stupid Question maybe? Chuck Church (Dec 26)
- Re: Stupid Question maybe? Baldur Norddahl (Dec 18)
- RE: Stupid Question maybe? Naslund, Steve (Dec 18)
- Re: Stupid Question maybe? William Herrin (Dec 18)
- RE: Stupid Question maybe? Naslund, Steve (Dec 18)
- Re: Stupid Question maybe? Florian Weimer (Dec 21)