I can ping a server, but I can not ssh to it

Question

I can ping my server:

» ping -c 1 42.24.53.224
PING 42.24.53.224 (42.24.53.224) 56(84) bytes of data.
64 bytes from 42.24.53.224: icmp_seq=1 ttl=62 time=1.10 ms

--- 42.24.53.224 ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 1.103/1.103/1.103/0.000 ms

I can trace the route:

» traceroute 42.24.53.224
traceroute to 42.24.53.224 (42.24.53.224), 30 hops max, 60 byte packets
 1  42.243.198.253 (42.243.198.253)  0.702 ms  0.751 ms  0.856 ms
 2  42.16.36.44 (42.16.36.44)  0.757 ms  1.123 ms  1.500 ms
 3  42.24.53.224 (42.24.53.224)  8.775 ms  8.725 ms  8.725 ms

I run a ssh in my server in a different port (to exclude firewall issues):

sudo /usr/sbin/sshd -ddd -p 33333

And I try to connect to it, but this hangs forever:

» ssh  -p 33333 42.24.53.224

What other debugging could I perform?

EDIT

» nmap 42.24.53.224 -p 33333

Starting Nmap 7.01 ( https://nmap.org ) at 2018-03-23 10:36 CET
Nmap scan report for 42.24.53.224
Host is up (0.0026s latency).
PORT      STATE    SERVICE
33333/tcp filtered unknown

Nmap done: 1 IP address (1 host up) scanned in 5.76 seconds

Solution

The fact you can ping means that the ICMP protocol is open and you can send and receive ICMP requests.

But the nmap command on port 33333 reports that this port is filtered, which means that there's something in the middle of the connection blocking it (most probably a firewall, either your provider's or your local machine's)

Comments

[nKn]

What's the output of nmap 42.24.53.224 -p 33333?

[Kamil Maciorowski]

What do you mean by "to exclude firewall issues"? Usually firewalls block incoming connections by default, admins allow some ports only (you may think of it as of exceptions from the default rule). Technically there's no difference (other than numbers) between TCP ports 33333 and 22 as far as firewall is concerned. You just tell your firewall to accept connections to one port or the other. So did you do this? Note it's the same if you connect to unused port, e.g. 33334. My first guess is: the firewall silently drops packets; it may be its default behavior.

[DanMetro]

@KamilMaciorowski I meant, in case the firewall is selectively dropping connections to 22. But maybe you are right and it is dropping connections to all ports (except 80, which seems to work)

[DanMetro]

@nKn added to my question

[nKn]

Well, there you go, ICMP is open and that's why you can ping the server, but port 33333 is filtered, which means that there's something in the middle of the connection blocking it (most probably a firewall, either your provider's or your local machine's)

[DanMetro]

@nKn right, could accept that as answer