Firewall in Ubuntu Server

root@myserver:/#ufw enable

Firewall is active and enabled on system startup

root@myserver:/#ufw allow 80

Rule added

root@myserver:/#

Source:

https://help.ubuntu.com/8.04/serverguide/C/firewall.html

Manual install in Ubuntu

1) download deb packages *deb
2) dpkg -i *.deb

How to change Ubuntu server 9.10 root password

By default there is no root password. By issuing the below command:
derya@ubuntu:~$ sudo passwd root
Enter new UNIX password:
Retype new UNIX password:
passwd: password updated succesfully
derya@ubuntu:~$