A way to monitor TCP port for a certain node

Yes or no, depending. http://tinyurl.com./e6m6

there is some key information missing here -- like the port numbers, do you mean 'listening for a connection' or 'a connection is established'

let me point you at this to give you some ideas: How to Detect and Clear Hung TCP Connections using SNMP - Cisco

shows the mib variables available and what you might be able to do using a UnDP

Thanks for the reply!

Maybe I'll be more detailed...

I need to verify whether a node (IP address) with certain port is connected to other node or not.

Usually, running NETSTAT regularly, on the listener node, will do the job. But I want to monitor it, frequently (lets say, once a minute) by Solarwinds.

Not depending on a switch in the way...

I would get the TCPConState table

do a gettable on  tcpConnState.<localIP>.<localport>.<remote-host-ip> and then check for an established connection

e.g. on the switch with IP address a.b.c.d  there is an established connection to ssh (port 22) from the host w.x.y.z from a random high port (38643)  

TCP-MIB::tcpConnState.a.b.c.d.22.w.x.y.z.38643 = INTEGER: established(5)

so, if I get the table TCP-MIB::tcpConnState.a.b.c.d.22.w.x.y.z

I would then look (possibly using some SQL) for a row that is established.

Note: Would not really recommend this other than for very specific connections, and it's not that easy (otherwise Solarwinds would not sell SAM for this purpose)