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/31 handoff

Posted: Tue Feb 11, 2025 2:09 pm
by nepeannetworks
Hi all.

I work for an Instant-Failover/Bonding company called Nepean Networks.
One of the things we do, is hand off our Public IPs to clients Mikrotik routers.

The big question I have is if Mikrotik's can accept /31 public IP blocks on it's WAN interface?

We prefer to use /31 blocks as it saves on public IP wastage.

Thanks everyone.

Re: /31 handoff

Posted: Tue Feb 11, 2025 2:15 pm
by holvoetn
Since 7.18beta they do.
See changelog.

So best to wait a bit until it reaches stable version before you start deploying.

Re: /31 handoff

Posted: Tue Feb 11, 2025 5:24 pm
by rextended
I work for an Instant-Failover/Bonding company called Nepean Networks.
One of the things we do, is hand off our Public IPs to clients Mikrotik routers.
Who cares what the company name is, and all the other bells and whistles, with the question?
It sounds more like an advertisement than a help request.

We prefer to use /31 blocks as it saves on public IP wastage.
You can do the same thing perfectly without /31.
Apart from .0 and .255 that I don't provide, but not for obvious reasons, but for others,
I don't waste even one IP and I use MikroTik from year 2007...

Re: /31 handoff

Posted: Wed Feb 12, 2025 1:38 am
by ConradPino
IMO OP introduced themselves as one professional meeting another in a professional setting and effectively presenting their business card.

Re: /31 handoff

Posted: Wed Feb 12, 2025 7:16 am
by LdB
They always have you just need to write them as a /32 with a /32 gateway route as rextended notes above.

Using /32 routes you can even have multiple customers to the same gateway and you reduce your IP loss by half over /31 :-)

I smell stupidity at play.

Re: /31 handoff

Posted: Wed Feb 12, 2025 11:34 am
by Datanav
Yes, mikrotik will accept the subnet.

Re: /31 handoff

Posted: Wed Feb 12, 2025 5:16 pm
by nepeannetworks
Yes, mikrotik will accept the subnet.
Thanks to all who answered sensibly. It's great to confirm the Mikrotik range do support /31 blocks. We've dealt with a few routers in the past which cannot handle /31 blocks.
Even Windows can't yet support /31 which is a surprise.

To the person who was talking about /32's, sure we do have a 'CPE NAT' system, in which we basically hand off one single IP in a 1:1 NAT sort of scenario, but the problem there is that on some routers when running IPSec tunnels, will advertise their end IP as a private IP instead of the Public IP. These problematic routers don't allow you to specify the IP manually so a /31 is the way around it. (I'm not at all suggesting that Mikrotik routers have that restriction).

Thanks again for the responses. I can add Mikrotik to our /31 supported list. Cheers all.

Re: /31 handoff

Posted: Wed Feb 12, 2025 5:20 pm
by rextended
sure we do have a 'CPE NAT' system,

I meant everything except that........