Subnet Size for BGP peers.

Thu Jul 30 21:01:36 UTC 2009

Doug McIntyre wrote:
> On Thu, Jul 30, 2009 at 12:22:27AM -0400, Barton F Bruce wrote:
>   
>> So what is wrong with a /31? We use /30s but if you are short on IP space, 
>> look at using /31 rather than /30 links. Cuts your space usage in half.
>>     
>
> /31's are only defined for point-to-point links. 
>
> Ethernet isn't considered PtP in general..
>
> Many devices won't accept a /31 on anything but a PtP WAN media type link.
> (or not at all). 
>
>   
Since it isn't PtP, one also has to allow the customer to connect 
multiple devices.