Setting up your own ip address for the interface card

You can use set any ip-address for your IP-address
ifconfig  interface IP-address netmask 255.255.255.0 broadcast 192.168.10.255

ifconfig eth2 192.168.10.12 netmask 255.255.255.0 broadcast 192.168.10.255


For bringing up interface use
ifconfig eth2 up

For bringing down the interface use
ifconfig eth2 down

striicthostkeychecking in ssh

Stricthostkey option in ssh

this can be configured in /etc/ssh/ssh_config  or it can be given in the command mode by specifying
ssh -o StrictHostKeyChecking=no 123.33.44.45
        

no option:  in this case when stricthostkey option is set to no:
1)when host key for the connecting server is not in the $HOME/.ssh/known_hosts file,it is added to the file after asking the confirmation from the server.
2)when there is a host key mismatch,it simply connects after showing a warning.
3)not advisable as security is very low.

ask option is the default option:
1)In this case also,when host key for the connecting server is not in the $HOME/.ssh/known_hosts file,it is added to the file after asking the confirmation from the server
2)But when there is a host key mismatch,it denies the connection showing the place where the mismatch has happened.

on option:
1)it is the strictest mode and unfriendliest mode..
2)In this case,when host key for the connecting server is not in the $HOME/.ssh/known_hosts file it simply denies the connection.
2) when there is a host key mismatch,it denies the connection.