Tcp port 554 open

nmap

I was running a routine security check of the machines I manage today and found in my nmap scans that TCP/554 is open, although when I run 'netstat -an' on the machine itself it doesn't show up, same result if I nmap the host locally.

I then tried connecting to www.google.com on tcp/554 and it is open and it seems all hosts 'have the port open'.

Obviously my ISP is doing something here but then I tried the same on my iphone via a 3G connection and it returns the same results. My ISP is a satellite ISP and my phone/3G connection is with a totally separate provider. Any ideas ?

Best Answer

I had a similar issue. For me, it turned out Apple Time Capsule was making it appear that ports 21, 554, and 7070 were open (it would proxy requests and not check if connections were accepted until later in the exchange.) So, if you're using an Apple networking device, I'd check there.

Related Solutions

NMAP: Check if port 80 and 8080 is open

Your NMAP command is fine. It's the service you're trying to connect to that is the "problem".

You can find that a "server" has an open port on 80 or 8080 but still not be able to connect it. For instance, I have about three dozen polycom phones that are accessible at port 8080 but they have bum config files. When someone tries to access them at that port they aren't able to connect.

And it may depend on how you're trying to connect. Even though its port 8080 maybe you aren't supposed to use a browser to connect to it.(I know - crazy idea).

Find out what type of device you're trying to connect to using this (you'll need sudo or root):

nmap -sS -O -p80,8080 192.168.1.0/24

Cisco – ACL Rule to Open UDP Ports

Because you are NATing from G0/0 to G0/1 you cannot use an access-list to allow traffic. NAT acts as a firewall so you need to use a Port-Address Translation rule. For the single port, that would look like this:

ip nat inside source static udp x.x.x.x 5060 interface g0/0 5060

The port range is a bit more tricky, as IOS doesn't usually deal with port ranges. However, it does have functionality built in for voice udp traffic ranges - however this is limited to port ranges which are multiples of 64. To catch your required ports:

ip nat portmap VOICE
 appl udp-rtp startport 9984 size 10240

This defines a port range of 10240 ports starting at 9984. Finally you need to apply this port map to NAT:

ip nat inside source list # interface g0/0 overload portmap VOICE

Where list # is the access list which encompasses the internal addresses you are translating to. An NMAP scan should confirm that the ports are open.

Hope this helps!

Best Answer

Related Solutions

NMAP: Check if port 80 and 8080 is open

Cisco – ACL Rule to Open UDP Ports

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