Using /31 for router links

Sat Jan 23 17:24:49 UTC 2010

That's a vendor specific issue.  Maybe you could take it up with them and 
ask what year they think this is?

tv
----- Original Message ----- 
From: "Florian Weimer" <fw at deneb.enyo.de>
To: "Seth Mattinen" <sethm at rollernet.us>
Cc: "nanOG list" <nanog at nanog.org>
Sent: Saturday, January 23, 2010 4:06 AM
Subject: Re: Using /31 for router links

>* Seth Mattinen:
>
>> In the past I've always used /30's for PTP connection subnets out of
>> old habit (i.e. Ethernet that won't take unnumbered) but now I'm
>> considering switching to /31's in order to stretch my IPv4 space
>> further. Has anyone else does this? Good? Bad?
>
> Bad.  For some systems, such tricks work to some degree only due to
> lack of input validation, and you get failures down the road (ARP
> ceases to work, packet filters are not applied properly and other
> fun).
>
> And now is not the time to conserve address space.  You really should
> do everything you can to justify additional allocations from your RIR.
> 