Port Forwarding or Port Triggering

roaf85

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Assume I know a basic bit about networking. My question is why would someone want to use Port Forwarding instead of Port Triggering.

For example on my network at home I have 3 computers that all connect wirelessly to a Linksys WRT54GS router which is connected to a wired computer and modem.

Now lets say 2 of those wireless computers want to download something from Blizzard Downloader. The result? Slow as hell. So I find the ports to open and go to the port forwarding page. The port forwarding setup page on the router asks me to input the "Application name", "Port Range", and "IP Address" of the request.

So this is where I get confused. I assume I enter in the IP Address of the wireless computer that is making the request.

For example if an IP Address assigned from my modem to my router (usually 69.186.blah blah whatever time warner decides), the the Linksys router assigns each computer in the chain an IP address usually starting with 192.168.1.101, and 102 so on.

Here is my problem lets say I forward ports to Wireless computer 103, well after 1 day (or one week since I changed the defaults) The device requests a new IP since the client lease time expires.

So wireless computer .103 could be .104 the next week and therefore it would negate the port forward.

Please chime in this is my understanding and I assume Port Triggering gets around this by being dynamic.
 
With Port Triggering the router will dynamically open a port when it senses a machine on the LAN establish a specific outgoing port. That would be one way to open ports even if a different machine, or same machine with a different IP requests it.

Another option (if your router supports it) is to statically set your DHCP leases, so that each particular machine will keep a particular IP and stay with traditionally forwarded ports.
 
static IPs are a must then disable dhcp

enable port security on your wifi

problem solved
 
With Port Triggering the router will dynamically open a port when it senses a machine on the LAN establish a specific outgoing port. That would be one way to open ports even if a different machine, or same machine with a different IP requests it.

Another option (if your router supports it) is to statically set your DHCP leases, so that each particular machine will keep a particular IP and stay with traditionally forwarded ports.

How would I do this?
 
static IPs are a must then disable dhcp

enable port security on your wifi

problem solved

There is no reason to disable the DHCP service itself. Matter of fact.....it's much better to leave DHCP enabled. Amongst the several reasons to leave DHCP enabled...some people are not network savvy, and say they are messing around..they disable DHCP service...and they screw up static IP assignments. Not knowing what to do, they flip the TCP back to obtain auto..and can't get to the routers web admin anymore.

You either...
*Create reservations within the DHCP service itself..binding a MAC address to a specific IP address, best option.
*or manually assign IP addresses outside the normal DHCP pool. Often home routers hand out addresses from 192.168.1.100 to .200 or whatever, they take 192.168.1.1 for themselves on the LAN side..leaving you with 192.168.1.2 to 192.168.1.99 for addresses you can manually assign without conflicts.
 
How would I do this?

Depends on the make/model router you have...but somewhere in the section that deals with DHCP, you may find an option that's called "Reservations" or "Static IPs". You enter the MAC of the PC you wish to become static, and you enter the last octet of the IP address you wish it to be. Once you save that setting..go over to that PC..run an IPrenew, and it will pickup the address you assigned it, all the time.
 
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