Difference between SPI and NAT based firewalls?

[megatexel]

Hey guys, I am trying to figure out which router I want to pickup here in the next couple days.

The requirements are basically just 802.11 B and G. My roommates don't know crap about computers and most people want to be able to use the direct connect feature in AIM to share pictures with thier friends. I was curious if an SPI based router would solve this issue, since none of us have ever been able to swap pics with both parties being behind NAT based routers.


SO, unless you advise me to get a SPI based router, I have been looking at the Linksys WRT54G. I really think those things are damn ugly, but it seems to fit the bill. Is there anything out there relatively in the same price range that would be equal or better?

 

[Need4Speed]

nat does only "network address translation". basically lets you use many pc behind one public address. this is generally not considered firewalling since no packet inspection in performed. Some memebers here <**cough cough JackMDS**cough > will say that nat is the most basic form of firewalling. its a matter of terminolgy.

SPI firewalls inspect all the packets to make sure that they belong to the current session and that they are what they claim to be.

Here are some google links that may help

 

[Need4Speed]

as far as direct connect, thats the fault of the program not the router...there are some soho routers that do SPI and port triggering, which will allow you to do what you want. linksys has a hard wired one (BEFSX41) that will do SPI and port triggering. not sure if they have a wireless one with those same options.

I'm not to worried about port triggering, so I run iptables on debian and then have a WAP behind that.

port trigger

alternatively you can open a crap load of ports and do it that way, but its a hassle constanly opening and closing those ports...hence the convience of triggering. the ports are only opened when the app calls for it . port triggering in theory is more secure since the ports are only open when you need them to be.