I´m having a problem on setting up the local area network using Mandrake Linux 10.0 with 2 PCs, a 4 port ADSL router and another 2 PCs under window 98. When I open samba, I only can see 1 host which run mandrake and 2 hosts run window, always lack of one host. Why?

The problem you describe can usually be tracked down to one of the following:

1) All SMB hosts are not registering with the same workgroup/domain name
2) One of the smb hosts (linux/samba or windows) on your lan has not yet won the master browser election. Sometimes this process can take 10 minutes or more if there is no PDC/ADS/WIN server on your network. i.e. all your systems netbios node-types are set to broadcast instead of hybrid.

A few things to check:

1) All smb hosts are configured to register with the same workgroup name. With Samba hosts, this is set in smb.conf or using SWAT.
2) To speed up the master browser election process on your LAN, insure that one of the Samba hosts wins the master broswer election process by increasing the "OS level" and set "local master = yes" in smb.conf.
3) Optional - Enable the WINS server function on "one" of your Samba hosts. Note: if you do enable the WINS server function, make sure you change "all" your SMB hosts to register with the WINS server, otherwise you will have some hosts broadcasting for the master browser while other hosts are quering the WINS server for the master browser.

FWIW: I enable WINS on my network.

Good luck!