port state issue

Applications IP Networking
1

Hello,

I have following issue:
traceroute connection works to given address(ip + port) but telnet(and other network tools) do not. How it is possible?

telnet 10.150.184.225 443
Connection refused

tracert -T -p 443 10.150.184.225
traceroute to 10.150.184.225 (10.150.184.225), 30 hops max, 40 byte packets
1 10.150.184.225 (10.150.184.225) 2994.735 ms 2994.715 ms 2994.691 ms

Thank You in advance
Kuba

2

check the traceroute man page. telnet and traceroute are completely different utilities.

     -p port
             Protocol specific. For UDP and TCP, sets the base port number used
             in probes (default is 33434).  Traceroute hopes that nothing is lis-
             tening on UDP ports base to base+nhops-1 at the destination host (so
             an ICMP PORT_UNREACHABLE message will be returned to terminate the
             route tracing).  If something is listening on a port in the default
             range, this option can be used to pick an unused port range.
3

I would like to check on which router/server/firewall the connection to given port is blocked.
How can I do it?

I tried to use traceroute, with wrong assumptions I guess.

4

there is no silver bullet way to do this. nmap might be able to help with determine if it is firewalled but you will not know the IP of the deviice blocking it.