Cisco 1801 Router - Port Forwarding?

Unanswered Question
Aug 22nd, 2008

Hi all.

I need to create a rule in my Cisco 1801 router, so that ports such as SMTP, HTTPS, VPN etc, are forwarded to the IP of the Server connected to the Router.

How do I create such a rule?

I have all the software installed and can access the Firewall feature on the Cisco SDM to edit rules and so on.

Cheers.

Chris.

I have this problem too.
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sachinraja Fri, 08/22/2008 - 03:03

Chris

Can you explain this a little more ? Ports such as smtp, https etc works on layer 4, and IP forwarding on layer 3 ! Now, the servers are normally accessed either by IP address or DNS name (which resolves to IP).. thus an end to end communication happens in a real world scenario !! what rule are you talking about here ?

Raj

ChrisWhite85 Fri, 08/22/2008 - 03:09

Hi there,

Sorry for not being too clear.

Our previous ADSL router had a firewall feature whereby you can say "if packets arrive from the Internet at port 25 (SMTP), forward this data to IP 10.0.0.1" for instance).

I want to be able to direct port traffic towards the correct server attached to the switch.

At the moment I imagine data is arriving at the switch but it doesn't know where to send SMTP, HTTPS, VPN packets and so on.

But the previous Router (a basic Netgear ADSL Router) had the facility to simply forward any data arriving on a specific port, straight to a specific IP address.

How is this done on the 1801?

Cheers.

Chris.

paaljakobsen Fri, 08/22/2008 - 03:21

If you don't use firewall feature, but only NAT, you can do the following to redirect port80(HTTP) from WAN to LAN :

int fa0

description WAN

ip nat outside

!

int fa1

description LAN

ip address 192.168.2.1 255.255.255.0

ip nat inside

!

ip nat inside source static tcp 192.168.2.2 80 80 extendable

ChrisWhite85 Fri, 08/22/2008 - 03:35

Port 80 we dont need forwarding to an internal server.

The following ports are forwarded to the main server on our current Netgear router.

SMTP TCP25

HTTPS TCP443

VPN-PPTP UDP1723

VPN-IPSEC UDP500

VPN-L2TP UDP1701

ASAPI-SSL TCP444

REMOTE DESKTOP TCP3389

IPSEC TCP500

I need these open on the new Cisco 1801 and forwarded to a Server IP, directly attached to the Router.

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