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New Member

Port range forward with a dhcp address?

I surprisingly didn't find much documentation about port range forwarding.

I would need to forward a few ports on my 877w, and I might have seen a solution between two static addresses. However, although my provider gives me a fixed ip address, I get it via dhcp, so I would like to build a static nat where the outside address is given via dhcp. This would mean using the interface as outside, but in that case I can't find a solution to forward a range of ports.

Anyone has an idea?

Thank you


New Member

Re: Port range forward with a dhcp address?


I think that you are asking to have a static translation on the outside interface to an internal private address based upon tcp/udp port. If so, here is how it would be done.

int fa1

"ip nat inside"

int fa4

"ip nat outside"

"ip nat inside source static tcp 22 interface fastethernet 4 22"

This short config would utilize fa1 as the inside interface for nat, and fa4 as the outside. This would then translate an inside address port tcp/22 to port tcp/22 on interface fa 4.

Assuming that your acl's/firewall allow it, someone could create a connection to the address on fa4 port 22, and it would connect to

Is this what you were looking for?

New Member

Re: Port range forward with a dhcp address?

Yes, kind of. This is what I did to configure my ssh, exactly on the same port.

In this case, however, I would like to go a bit further: I would like to do the same for, for example, all the ports between 7001 and 7050. What I can do is to write the same line 50 times, every time with a different port (which is at the end what I did), or maybe there is a better solution. If I make an access list I can specify the port range, and I was hoping that there was a similar solution for static nats.


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