Configuration /etc/hosts IPv6 on Debian Lenny AMD64 PC on the LAN (private LAN)

By default IPv6 on Debian 5 (Lenny) has been active. To ensure the connection to the LAN network to run well, the parameters that must be filled are as follows:
127.0.0.1 localhost
:: 1 localhost-localhost IP6-loopback
fe00 :: 0-localnet
ff00 :: 0 IP6-mcastprefix
ff02 :: 1-allnodes
ff02 :: 2-allrouters
ff02 :: 3-allhosts
If this configuration is accidentally deleted (i did), the network connection will lost and often become very slow.