Anyone can open a connection to any port of the TCP/IP stack, as long as there is a server listening on that port, unless you have set up TCP/IP to block certain IP addresses or are using a firewall. On the other hand, you have to authorize userids to listen on p orts below 1024 -- at least with ASSORTEDPARMS RESTRICTLOWPORTS, with is the default in current versi on of VM TCP/IP.
I TELNET to port 25 (on VM or on other servers) from my PC all the time. I can also do it from CMS on the same or any other VM system that is inside our firewall. You do ha ve to know what the SMTP commands are. They are documented in the VM TCP/IP manuals, among ot her places. This is very useful for debugging. It is also what makes spoofing email so eas y. We have VM SMTP set up so it will not act as a relay (with FORWARDMAIL N O). Otherwise listening on port 25 would violate corporate standards. With relaying set off, all anyone can do is send in email, which they can do anyway without using TELNET. Many Internet protocols work via TELNET to the appropriate port. (HTTP is another example. TELNET to port 80.) I assume this was to make it easier to develop and de bug Internet protocols. On Mon, 23 Oct 2006 09:54:21 -0700, Schuh, Richard <[EMAIL PROTECTED]> wrot e: > -----Original Message----- > >Glen Herrmannsfeldt Wrote: > >Anyone can open a connection to port 25 and type SMTP >commands into that connection. That is TCP/IP as designed. > >Are you saying that any VM user can open a connection to port 25 of the VM IP Stack, or do you mean external (to VM) users? > >Regards, >Richard Schuh >======================== ========================= ========== =============
