I have installed talk on centos, turned it on by editing xinetd.d/talk and setting disable=no.

I have restarted xinetd (service xinetd restart) and verified that talk is configured to start (chkconfig --status-all).

output from netstat -l | grep -i talk:
udp 0 0 *:talk *:*

telnet to ports 517 and 518 both indicate CONNECTION REFUSED when attempted from localhost, and CONNECT FAILED from a remote windoze box.

"talk user" displays "[ Error on read from talk daemon: Connection refused. Press any key... ]──", then "[Checking for invitation on caller's machine]". nothing appears to happen after that.

output from iptables -L:
Chain INPUT (policy ACCEPT)
target prot opt source destination

Chain FORWARD (policy ACCEPT)
target prot opt source destination

Chain OUTPUT (policy ACCEPT)
target prot opt source destination

what am i missing? shouldn't either port 517 or 518 respond to telnet? what else can i do to get talk running?

solved my own problem: had to edit xinet/ntalk and set disable=no, not xinet/talk (both files exist).

once i got talk working, i edited xinet/talk and set disable=yes, restarted xinetd, and talk still worked.

so... my question is now more academic: what is talk for, if ntalk is the real file?

Seems like they are alternative tools http://network.terramail.pl/

I believe way back when the 'Well Known Ports' list was being compiled, they were actually 2 different tools: talk only worked locally & you needed ntalk to talk across a network.
OTOH, I could be wrong