You would have one spare subnet for growth and you would only be advertising out one summary address for the whole site.ДЎ92.168.0.0 -> 192.168.3.0/24 and summarise as 192.168.0.0/22 or 255.255.252. So lets says a site needs 2 subnets for users/servers etc. What i meant though is for each site you allocate IP addressing. The loopback address is used to route outgoing IP packets to the TCP/IP protocol. You can use a subnet that is not part of the site subnet(s) if you want and yes it will be fine routing, you will just be advertising another subnet. In TCP/IP networking, Loopback Address is the special IP address 127.0.0.1. To test whether TCP/IP is installed correctly on a machine running Microsoft Windows, type ping 127.0.0.1 at the command prompt. If I use separate subnet from the remote site subnet, then I can't summerize and need an another route learned. The loopback address is used to route outgoing IP packets to the TCP/IP protocol stack bound to the network interface card (NIC) and back to the source application without actually placing the packets on the network.

Care should be taken when choosing your address that it is also not in the same address range as your work or home network settings.

This was you don't really have to waste address space adn could make a interface appear as a decent subnet. Mike is using one block like /24 for every site's loopback. On the Internet Protocol Version 4 (TCP/IPv4) Properties page enter IP information for an IP address in one of the private address space (10.x.x.x, 172.16.x.x or .x). Say for example you wanted to use a loopback and had an interface in the box, you could assign a 30 bit mask to the loopback and use 'ip unnumbered loopback x on the interface's'.

Loopback ip address