Ronald van Gogh
4750 is the official port no. for RSCD agent.
Also you can use 4752 port no. but you have to put entry of 4752 port in app server secure file for particular server.
The misconception seems to be widespread. All my services files say ssad/4750 and rscd/5750 also. That's why I always specify the port number rather than the name.
But it has me wondering... What is SSAD? I've spent half an hour looking and can't find anything except that supposedly it uses port 4750.
SSAD = Simple Service Auto Discovery
According to IANA, Port 4750 is registered by a contact at dorrigomedical.com
As far as I can tell, that domain no longer exists
RSCD = Bladelogic Agent Service
According to IANA, Port 5750 is registered by a contact at bmc.com (In fact he is a VP of R&D)
To correct Vipin, 4750 is the default port number used during installation, but the RSCD Agent can be configured to use any available port.
As SSAD appear to be defunct, using the default 4750 seems to rarely cause a problem
this is really a non-issue. look at other ports in the /etc/services file.
1521 - 'ncube license manger'. gee, that's also the default oracle tns listener port
8080 - pretty much the default port for tomcat, but it's 'www caching service', also used frequently for proxies.
i'm sure there are many others like this. most services can listen on any port you want and there are more than 65536 products that listen on a port.
I can't quite agree that it is a non-issue. I would say that it is a very small issue. I wouldn't be stressed at all if we didn't have a different port registered. That leads to confusion.
May I suggest 2 things?
1) Can BMC unregister port 5750? That will reduce confusion. *I* know enough to use the port number, not the port name, but when Linux admins try to install the agent sometimes they try to use the port name. If there weren't an rscd named port then they would have to look for the number. But there is a named port, and it is wrong.
2) Improve the documentation.
2a) When port 4750 is first introduced in the documentation, put a footnote in that someone else registered the port, but we are unaware of conflicts with SSAD in practice.
2b) Documentation about opening the port in iptables under Linux and possibly other host base firewalls needs to have an short but clear paragraph using the port number rather than the name. The SSAD conflict may be mentioned in documentation I have not seen, but it isn't in the docs I learned from.
What do you do for oracle? clearly that port is in conflict. As are so many others. relying on the name of the service is a bad idea imo – you should know what actual service is listening on the port and not just assume it’s what /etc/services says.
I agree with you that using a portnumber instead of the name of the services is much smarter. However, the services file is there for a purpose and there are people who rather like to use the names instead of the numbers.
I then agree with Kai to have at least port 5750 unregistered to avoid confusion.
Kind regards, Ronald