We have RHEL AS 3.0 with Oracle 9i database.
We have 5 branches(100 users) connecting to our oracle database which is inside the linux server.
We have to restrict the SSH connection by ipaddress.
We have not enabled the browsing(internet) option in our server.
I just want to disable everyone to access our server except from 3 ip's.
So please go through the following and correct me if im wrong....

Step 1:
sshd: ALL

Step 2:

Step 3:

Port 110101010 (if i change the port number will it affects the users who are all connecting to oracle database?)

PasswordAuthentication no
PermitEmptyPassword no
StrictModes yes
Protocol 2

if i have to do any other changes in the step 3 please point out the changes.

Step 4:
i checked in /etc/sysconfig but there is no file called iptables.
there are 2 other files ip6tables-config and iptables-config.
So i thing the iptables are not installed. if its must then advice me the steps.
Also, after doing step1,2,3 the step 4 is not necessary....Am i right?

Finally my question is.....if i do the above changes in my linux box will it affect the oracle database which is inside our linux box?
And also, the users who are all connected to oracle database will be affected....

Please treat this as urgent.....

thanks & Regards