Migrated notes from mdnotes

Port information on Linux.md

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+# Why is that port open?
+
+> I don't know why are you concerned about processes listening on localhost (meaning there is no access to that port from outside). But if you really want, you can see which package is involved.  
+  
+First of all find out what process is using it: (run as root)
+
+```shell
+netstat -tunlp | grep PORT
+ps ax | grep PROCNUM
+dpkg --search EXECUTABLE
+```
+
+| Variable       |  Description                                               |
+|:-------------  |:---------------------------------------------------------- |
+| **PROCNUM**    | process number seen on the previous command output.        |
+| **EXECUTABLE** | the executable with full path of the above process number. |
+
+Then examine that package with aptitude show or whatever.
+
+## Reference
+* [[SOLVED] What happened if I disable "rpcbind"?](https://www.linuxquestions.org/questions/linux-networking-3/what-happened-if-i-disable-rpcbind-4175594881/#post5638538)