Nmap Hackers: Re: SNMP to nmap?

From: Evan Brewer <dmessiah_at_silcon.com>
Date: Thu, 17 Dec 1998 12:14:07 -0800

On Thu, Dec 17, 1998 at 01:18:19PM -0700, ubik wrote:

> This isn't really true. NFS is a special case since it typically runs
> on a well known port. Most (all?) of the other RPC services allocate
> ephemeral ports so you can't determine which RPC service is running on a
> certain port in a reliable way by simply portscanning.

Well as port scanning goes, I've never had a situation where I was looking for
an rpc service that didnt sit on a static port.

> The point of RPC scanning that in situations where packet filters
> prohibit connections to the portmapper (often advocated on CSU to
> "enhance security") you can still easily find out what port a particular
> service exists on by sending requests to invoke to NULL procedure for
> the service to every open UDP port. If you find the service, you will get
> a response.

My sentiments exactly.

dmess0r
Received on Dec 17 1998