I'm trying to setup a raspberry pi (OS: Ubuntu server 20.04 LTS) in order to connect through ssh on default port 22.
I'm using a 4G sim with a TpLink Archer MR 600; my ISP is assigning me a private dynamic IP address so I managed to configure a ddns using the free no-ip services.
- Created an hostmane called "robman.ddns.net", I'm able to resolve it using nslookup.
- Installed noip2 package for dynamic IPs management
- Assigned a fixed IP to my raspberry, reserving it on the router
- Opened ports on my router via Virtual servers and port triggering
- Started the ssh session on the pi 4
When I try to connect to it using ssh -vvv ubuntu@robman.ddns.net I received Connection-timeout but if I try to connect using the private local IP address I'm able too establish an SSH session.
nmap scan
Starting Nmap 7.80 ( https://nmap.org ) at 2021-07-27 17:52 CEST
Nmap scan report for robman.ddns.net (***.**.***.***)
Host is up.
PORT STATE SERVICE
22/tcp filtered ssh
Nmap done: 1 IP address (1 host up) scanned in 2.22 seconds
As another note: when I try to execute ping robman.ddns.net the address seems to be solved but the ping it seems to be stuck!
cat /etc/resolv.conf
nameserver 127.0.0.53
options edns0 trust-ad
Any hints? Thanks
