On 3/3/20 12:24 PM, Farley, Peter x23353 wrote:
From the other responses it would seem that getting a "host name" for the remote IP address may in fact require a "reverse DNS" lookup to get that name.
(Reverse) DNS is the contemporary way to get IP to host name mapping. There are others, but they have fallen out of favor years (decades?) ago. I also don't know if the mainframe supports them; hosts file, NIS, etc.
I wonder, does "reverse DNS" get you to the actual connected system (presumably a PC of some sort)
Most services only look at the remote IP of the established connection.
even if the PC is behind a router and uses DHCP for a local network address (so only the router has a "public" IP address)?
(Reverse) DNS may get you the hostname of the IP behind the router /if/ that IP is known. Most SOHO routers like you are describing NAT to a single external IP, which is seen by the mainframe. As such, the mainframe won't see the IP that is behind the SOHO routers like you are talking about.
What if the PC also uses a VPN to connect to the remote system?
Same thing applies. It's all about the remote IP address of the established connection.
What about "thin client" setups? What does a system that gives you a 3270 screen in a browser window (i.e., no actual tn3270 software on the PC) look like on the VTAM side? What IP address does it see connecting?
Same thing applies. The mainframe will see the remote IP address of thee established TCP connection. This IP will most likely be the server that is providing the web-to-3270 gateway function, which is decidedly NOT the thin client.
Interesting questions.
Indeed. -- Grant. . . . unix || die ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
