Router that assigns external NAT ports in Sequential manner?
I'm looking for a router that assigns external NAT ports in Round-Robin manner i.e. first connection gets port X, 2nd one gets X+1, then X+2 and so on.
Anyone know which cheapest model has this feature? Most of the home routers either have one-to-one mapping or random port allocation.
Re: Router that assigns external NAT ports in Sequential manner?
Probabily no such beast - because common IP stacks as well as IP tables are not implemented that way. What should happen when the port 65k is reached? What should happen if a port is occupied? That's why random is standard...
Re: Router that assigns external NAT ports in Sequential manner?
@schumaku wrote: Probabily no such beast - because common IP stacks as well as IP tables are not implemented that way. What should happen when the port 65k is reached? What should happen if a port is occupied? That's why random is standard...
Actually, its common in enterprise firewalls. They either go with Random port assignment or Sequential. When 65535 is reached, then the counter resets, and when the port is already in use it skips to next available port number.
I have come across consumer ADSL models from other brands that do port assignment in sequential manner, but trying to find an ethernet router that does the same.
Example: Local IP/Port -> Natted Public IP/Port 192.168.1.20:42346 -> 45.86.59.96:54219
Re: Router that assigns external NAT ports in Sequential manner?
What for should this predictable behavior be good for? The world does everything to avoid any kind of predictable behavior of IP stacks allowing to identify insights if the security infrastructure in use.
In this network business longer than enterprise TCP/IP firewalls exist, early adopter of CP FW-1, and never cared about what the firewall host IP stacks does handle port assignments, being in direct routing, NATing, ....
Re: Router that assigns external NAT ports in Sequential manner?
Working on a NAT Hole Punching software, so need to test port prediction behavior and success rate.
I'm not debating the merit of random vs sequential port assignment. Fact is there are consumer to enterprise leverl routers/firewalls that do sequential external port assignment and I need to test my software against this behavior. Just seeing if Netgear has any product that could be of help to me.
