Port forward

[tech128]

Hello

I have a problem with port forwarding.

I use simple 6 yrs old 4/1 port Cisco router (I don't remember model @this moment.

i've added rule:

ip nat inside source static tcp local-ip port global-ip port extendable

and it works from outside (WAN)

but when I'm tryin to

telnet global-ip port

from INSIDE of the network it doesn't work.

When I use simple routers for home users (like D-Link, TPLink etc) and set them to forward port to local machine

it is reachable from INSIDE and OUTSIDE of the network (using OUTSIDE ip address)

What do I have to do to make it working on Cisco router too ?

Best regards

[Mark Malone]

Hi

why would you want to telnet to your outside ip address from inside your network and not telnet to a private ip on your network from your LAN is there a reason  ?

I would disable telnet and use ssh  either way, its unsecure and your password can be seeing in a packet capture

[tech128]

Hi

I use telent only for tests / examples.

In the fact there is other service working @this port.

Why to call local machine from inside of the network by external address ?

In this case service working on local machine does self test by callin itself on external adress :(

and I have no option to change it....

best reagrds

[tech128]

Any idea ?

[Bruno]

Hi there tech128,

I had the same problem and got it to work with the help from a friend.

I have to say that I have no deep knowledge of Cisco routers. I have no formal education in networks and maybe my answer won't work for you.

My port-forwarding config when I had the same problem as you:

On interface vlan1: ip nat inside

On interface GigabitEthernet8 (wan port): ip nat outside

ip nat inside source static tcp lan-ip port interface GigabitEthernet8 port

New configuration that works for me just like you want it to:

On interface vlan1: ip nat enable

On interface GigabitEthernet8: ip nat enable

ip nat source static tcp lan-ip port interface GigabitEthernet8 port

I would also like to answer the question from Mark Malone as to why doing this and why do I need it:

I have a NAS running several services and some of them have Android apps to access content and services. On the app I always prefer to configure my domain as host for the service. Otherwise I would have to configure the connection again when I am home and once more when I am on the road. Considering I use really long and complex passwords it was impossible to have access everywhere this way.

Now I configured all apps with my domain as host and I can access both from home and on the road without entering any login information every time.