2600 Port Redirection/Forwording 1

[plexter]

Hello,

I am trying to figure out how to redirect a range of ports to one of my internal servers (on a private address) from the internet. In my situation I want to open up quite a lot of ports which will be used for FTP PASV connections.

[internal FTP PASV server] <--> [Cisco 2600 NAT] <--> [INTERNET]

I understand how to use NAT to redirect a single port but this just wont work for a range as well it would be quite time consuming to install for each of the PASV ports!

NAT way: IP NAT inside source static tcp IP PORT INTERFACE/IP PORT

So please if anyone knows how I can achieve this please let me know.

Thanks

 

[KiscoKid]

You will probably be better of just assigning a spare public IP address to the server in question and then building a standard static NAT translation as follows:

ip nat inside source static a.b.c.d w.x.y.z

where a.b.c.d is your server's internal IP and w.x.y.z. is a spare public IP

 

[plexter]

Thats assuming I have one

I suppose its possible to work that into my current configuration. Than again assigning a public IP to everything kind of defeats the whole point of NAT. But I mean surely its possible to forward a range of ports. This "feature" is available on any home "router" I just cant see Cisco not including this almost manditory feature!

Do you know how to do this regardless?

Please let me know,
Thanks for the reply

 

[KiscoKid]

I'm not convinced you can do this and I don't have a Cisco box in front of me at the moment to give it a whirl. I did however have an idea that may work - *may* being the operative work here. This idea is meant to be used for another function of Cisco networking but it may work for you. Try the following:

ip nat pool ft a.b.c.d a.b.c.d netmask 255.255.255.0 type rotary
ip nat inside destination list 100 pool ftp
access-list 100 permit tcp any any range 1023 9999

where a.b.c.d is your internal server's real address.

Let me know how you get on.

 

[plexter]

Wow I had a feeling it would have to do with combining a list with nat, just never could quite put my finger on how!

Anyway seems to be working wonderfully. Thank you very much for your help.