i have no idea on how to configure the nat on the ciscoo 871 series router does anyone know how to do this

Have you checked out Cisco's website?

How are you configuring the router??

GUI or comand line.

!
int <lan>
ip nat inside
!
int <wan>
ip nat outside
!
ip nat inside source interface <wan> overload
!

Job done

i have the same question about nat... also i have the same router

Lucky I just showed you how to do it then eh?

With the 871, consider using SDM to get the initial configuration set. Why? The 871 has 1 - layer 3 port (F4/connected to DSL/Cable modem), 4 - layer 2 switchports (F0-F3/desktop PC's), and 2 - wireless radios (A and G). SDM does a good job at creating a bridge-group (BVI1) that includes the layer 2 swichports and both wireless radios (which can share the same DHCP scope). Plus it creates the necessary virtual radio interfaces required for the bridge-group assignment and configuring a local radius server for authenticating wireless clients.

Also, SDM did a good (not great) job at configuring the IOS firewall feature set. i.e. ACL's

hi, what you mean with the "!"
that command is not recognized in my cisco command line interfase

thanks

its just a separater in cisco configs to make em readable. The router will ignore them and carry on to the next line.

thanks i will try it

Thanks but before run the code you provided me i would know how to setup lets say the common configuration for RealVNC connections: and this will be a typical NON-CISCO scenario:

Outgoing:
PC(RealVNC Viewer) -> Netgear Router -> INTERNET

Incomming
INTERNET -> Netgear Router (forwards the requested 5100 port to the assigned Lan IP -> PC(RealVNC Server) It listen from the forwared port: 5100

It made sense?

How can do it under cisco kindom?