nanog mailing list archives
Re: Best practice for ptp/loopback numbering for "small" enterprise multihome setup
From: William Herrin <bill () herrin us>
Date: Fri, 26 Mar 2021 12:01:36 -0700
On Fri, Mar 26, 2021 at 11:07 AM vom513 <vom513 () gmail com> wrote:
As I said in the tl;dr - my main point of contention here is breaking up my /24 I.e. use the very top /30s / /31s for ptp/loop. I would then have at most the bottom /25 to use contig. on my “lan” - and I would need to use the next /26, /27 and so on in some manner for the space to be useable...
If you feel like getting fancy... Use /32 routes to reclaim the unused base and broadcast address in any /30s Pick the next largest size block that has your /24 neither at the start or end and assign that to your lan. Use proxy arp and more specific routes to grab traffic that doesn't fall in the /24 or is part of the loopback and point to point numbering and move it off the lan and towards its destination (including upstream). This way, every address in the /24 that you don't specifically use elsewhere is usable as a unicast address on your LAN segment, including the .0 and .255 addresses. e.g. You have 10.0.1.0/24 Put 10.0.0.0/22 on your LAN Add proxy arp and route 10.0.0.0/24 upstream Add proxy arp and route 10.0.2.0/23 upstream Add proxy arp and route 10.0.1.254/32 to your first router loopback etc. If you're really clever you can convince the stations that 10.0.0.1 is the default gateway but convince the router that 10.0.0.1 is upstream so that the router doesn't even need a dedicated IP address facing the LAN. Regards, Bill Herrin -- William Herrin bill () herrin us https://bill.herrin.us/
Current thread:
- Best practice for ptp/loopback numbering for "small" enterprise multihome setup vom513 (Mar 26)
- Re: Best practice for ptp/loopback numbering for "small" enterprise multihome setup Randy Bush (Mar 26)
- Re: Best practice for ptp/loopback numbering for "small" enterprise multihome setup Tom Beecher (Mar 26)
- Re: Best practice for ptp/loopback numbering for "small" enterprise multihome setup Blake Hudson (Mar 26)
- Re: Best practice for ptp/loopback numbering for "small" enterprise multihome setup William Herrin (Mar 26)
- Re: Best practice for ptp/loopback numbering for "small" enterprise multihome setup Blake Hudson (Mar 26)
- Re: Best practice for ptp/loopback numbering for "small" enterprise multihome setup William Herrin (Mar 26)
- Re: Best practice for ptp/loopback numbering for "small" enterprise multihome setup Lukas Tribus (Mar 26)
- Re: Best practice for ptp/loopback numbering for "small" enterprise multihome setup Blake Hudson (Mar 26)
- Re: Best practice for ptp/loopback numbering for "small" enterprise multihome setup Blake Hudson (Mar 26)
- Re: Best practice for ptp/loopback numbering for "small" enterprise multihome setup Randy Bush (Mar 26)
- Re: Best practice for ptp/loopback numbering for "small" enterprise multihome setup Lukas Tribus (Mar 26)
- Re: Best practice for ptp/loopback numbering for "small" enterprise multihome setup William Herrin (Mar 26)
- Re: Best practice for ptp/loopback numbering for "small" enterprise multihome setup Lukas Tribus (Mar 26)