This is related to this bug report: Debian bug #316099

The system hostname should always be resolvable even when the network is down. Basically, some applications still try to resolve a host via 127.0.1.1 so in order to accommodate, it is kept by default on current debian-type distributions.

The general rule of thumb is: If you don’t have a permanent IP address for your host, use 127.0.1.1.

# No Permanent IP
172.0.0.1 localhost localhost.localdomain
127.0.1.1 blogs

# Permanent IP
172.0.0.1 localhost localhost.localdomain
102.12.153.253 blogs

Another approach is discussed here.