port for mountd

[Susan Eck]

What is the standard port that the mountd daemon should be running on? I have three N-class servers all running HP-UX 11.0 and the mountd daemon is running on different ports on each.

Should the port used for mountd be a reserved port?

Thanks,
Susan

[Santosh Nair_1]

You can find out which port(s) mountd is using by the command:

rpcinfo -p |grep mountd

mountd registers itself with the RPC daemon and this command shows the port that the RPC daemon assigned to the mountd daemon.

-Santosh

[Anthony deRito]

Susan, the reason you see a different port each time is because vendors like HP and Sun do this kind of thing but don't document the ports. Follow this thread for more information...

http://forums.itrc.hp.com/cm/QuestionAnswer/1,1150,0x7496abe92dabd5118ff10090279cd0f9,00.html

Tony

[Enno Baars · Accepted solution]

Hi Susan!

Just the other day I was asking the same question. :-)

Some facts in short:

* In former days RPC used to be on port 635.

* Mountd is an RPC-Service. The idea behind RPC is to have a so called portmapper which you can inquire the ports at. Try the command "rpcinfo -p ". You don't need static ports then.

* The standard behaviour for an RPC service is to select any unused port at startup and register that port with the portmapper.

* RPC services and especially the portmapper pose a serious security threat to a server system! Therefore most OS are switching back to static ports for all services. (This allows firewalling.)

* The standard way for telling mountd to bind to a predefined port is to use the option "-P" when staring mountd. E.g. "rpc.mountd -P 635"

* HP-UX 10.20 does not recognize such an option. (I don't know about 11.x - just try it)

* Mountd runs on privileged (sometimes called "reserved") ports today, i.e. Ports greater 1023. This is due to security reasons - only root can access privileged ports on the local machine.

* By using the option "-p" (on HP-UX 10.20) you can allow mountd to use unprivileged ports as well.

I hope this answers all your questions. :-)

Cheers,

Enno.

[Enno Baars]

*** CORRECTION ***

Sorry, I goofed up....

The first fact should read of course:

* In former days mountd used to be on port 635.

Cheers,
Enno.