Filtered port with virtual server setup on a NAT

I have a Symphony SY602 ADSL router and I want configure a dynamic DNS to access my system remotely. I made a NAT virtual server in routers configuration and this is what I configured:

Server Name     External Port Start     External Port End   Protocol    Internal Port     Start     Internal Port End   Server IP Address
SSH             2222                    2222                TCP/UDP     2222                        2222                192.168.1.2

While I can connect to ssh using my internal IP address 192.168.1.2, over WAN this operation will stock in connecting to the port.

Here is an nmap -sS result on my ip:

Not shown: 996 closed ports
PORT     STATE    SERVICE
23/tcp   open     telnet
80/tcp   open     http
2222/tcp filtered EtherNet/IP-1
5431/tcp open     park-agent

As it is obvious the port is filtered. I checked iptables and it's disabled, but I can't find why this port is filtered!

Shahinism

Posted 2014-11-02T19:39:49.130

Reputation: 203

From where did you try to use nmap and your SSH client? Inside your own network? – Daniel B – 2014-11-02T19:42:42.363

Yes! Actually using the 192.168.1.2 system. – Shahinism – 2014-11-02T19:46:30.393

Unless your router does NAT reflection (aka NAT loopback, NAT hairpinning, ...), you can’t test it that way. What you see on nmap are your router’s internal services. Your connection has to come from the WAN side. – Daniel B – 2014-11-02T19:53:47.497

Using this service I ran another nmap session and as you suggested the port is open but, I can't still get ssh working! How can I figure out what the problem is?

– Shahinism – 2014-11-02T20:45:50.397

@DanielB Thank you, It's working from other computers. It's awesome ;-) – Shahinism – 2014-11-02T20:53:15.800

Filtered port with virtual server setup on a NAT

Answers