From what I gathered via trial-n-error, all I have to do for setting up
multiple external interfaces is by doing the following steps:
Start->Firewall->Firewall Configuration. Click on 'External I/F Tab'.
Then input El90x1,El90x2,El90x3 then press 'OK'. (for 3 external interface
Is this correct? (Since there are no real ways in the Admin manual for
setting this way up).