Routing

Can anybody help me with configuration of BGP with /31 IP address

Its just a query , I would to know when and how we use this setup

/31 is basically when you're on point to point & /31 mean you want to save IP address space.

Can you use the configuration shared above, it for iBGP & for eBGP, change type internal to external.

/31 prefix gives you only two addresses (network and broadcast address) for the subnet. You can use these IPs for point to point connectivity. It helps you conserve IP space.

Using a /31 subnet mask helps conserve your IP address space for point to point links.

It doubles the number of links that you can number from a given block of IP addresses.

If you think of large organisations that have hundreds of WAN links but are rapidly running out of address space.

This is especially useful if you have paid for a block of public addresses from your ISP and so you want to utilize as many of them as possible.

Not only can a /31 subnet be used on serial interfaces but it can also be assigned to ethernet interfaces.

test@re0# show protocols bgp
group CPE {
    type internal;
    local-address 60.60.60.2;
    family inet {
        unicast;
    }
    peer-as 44;
    neighbor 60.60.60.1;

test@re0# show interfaces xe-5/3/0
unit 0 {
    family inet {
        address 60.60.60.2/31;
    }
    family mpls;
}

@karand, 60.60.60.1 would be on a different subnet from 60.60.60.2. Your neighbor has to be 60.60.60.3 if your IP is 60.60.60.2/31.