Hello, I am having issues using /31 on my Mikrotik device. I have IPsec tunnel through GRE that I’ve been using with a /30 with no issue. I’ve decided to change my IP scheme and was going to use /31 for both sides.
I can ping each router through the tunnel but traffic will not pass through and it times out.
Routes are alive and gateway is set up correctly.
Any idea how this could work?
/31 is not supported, use /32
Thank you for the fast response.
I’ve now tried to use /32 for the tunnel IPs, but the tunnel will not come up.
Neighbor is UP with those IPs, but pings are not going through
There is a small hack to use /31 addresses - one address to be the local address and the remote one to be specified as the network. For example, site 1 - address=192.168.1.0 & network=192.168.1.1, site 2 - address=192.168.1.1 & network=192.168.1.0
this is considered PtP addressing and works fine
Not everybody knows the name for it ... and certainly not everybody knows how to use it properly ... hence post by @TheCat12 (which is, unlike yours, useful)
Here are some related info:
http://forum.mikrotik.com/t/point-to-point-31-addresses/29492/1
particularly:
http://forum.mikrotik.com/t/point-to-point-31-addresses/29492/1
And this post is the one that (for me) is easier to remember, the concept of a mirror of a /32:
http://forum.mikrotik.com/t/point-to-point-31-addresses/29492/1
now some more know though