difference between NetFilter and IPFilter

hi all,
>From what ever docs i have quickly gone through , i feel IPFilter is
similar kind of thing as compared to Nefilter framework on Linux.
Please correct me if i am wrong .
So i just wan to validate this assumption and know differences between
them.

Q 1: Is IPFilter also framework like it which allows me to write new
kernel module which allows me to insert my hooks for inbound and
outbound TCP packets.
Or
is it a application that allows me to define some firewall rules and
doesn't allow insertion of any of such hooks
through a kernel module.

Q:2 How is it available on Linux ?? as part of standard Linux Kernel
or kernel module which can be inserted into a standard linux kernel ??

if module on linux , does IPFilter uses Netfilter framework
underneath to implement
those PRE_ROUTING and POST_ROUTING hooks ??

Q:3 Can i get a list of linux distribution with which it has been
tested to work successfully.

Q: 4 If i want to write a kernel module to intercept TCP packets , and
i have options of using IPFilter and Netfilter , which should i choose
?? .Once linux task is complete i would like to go ahead with Solaris
and AIX.


Thanks ,
Rohit

I guess IpFilter is not framework kinda thing like NetFilter but it is
something which sits on top of NetFilter or other such things(e.g. pfil
on Solaris and *BSD* ).
But from this i think i should use same strategy as that of IPFilter
and use same hooks which it uses for portability.


Thanks
Rohit