Firewall Architecture in System

[faiza athar]

Can anyone help me regarding different firewall arrangments with the legacy system?
I am looking for a source or questions which can test me regarding this topic.
Any input will be appreciated.
Another question
7. Which middle ware solution is BEST fit when anonymously accessing the server under the firewalls of Internet.
a) RMI
b) Servelets
c) CORBA
d) EJBs
Any more questions like these???
thanx
F

[Suresh Gnanasekaran]

fazia,
7. Which middle ware solution is BEST fit when anonymously accessing the server under the firewalls of Internet.
a) RMI
b) Servelets
c) CORBA
d) EJBs
Answer is : b)
For a) c) and d. If you have Firwall then most cases they wouldn't allow other Protocols like RMI-IIOP or RMI-JRMP. Mostly the firewall is configured to pass through HTTP. So Servlets uses HTTP so any one can acess servlets. Another restriction is port. Servlets can be acessed in normal port 80. To use RMI or CORBA the Port has to be diffrent. Mostly when configuring firewall then wouldn't open port other than 80 for security reasons.
Thanks

[faiza athar]

Thanx for the elaborate answer.
But how do we choose the firewall between WebServer, AppServer and the Database. One between each of these so that its the following scenario
Firewall 1
------------
WebServer
------------Firewall 2
AppServer
------------Firewall 3
Database
What is http-tunneling here? How much do we need to know abt it?
What port do we use with RMI-IIOP , or JRMP etc?
Can someone plz throw some light on the above picture. how the process works?
Thanx much!
F