I would like to know if there is a way to send message between vty (telnet) sessions.
IOS has this capability, see below, user tiger is sending msg to lion:
RTR#send vty 323
Enter message, end with CTRL/Z; abort with CTRL/C:
Hi there, How are you?
Line User Host(s) Idle Location
* vty 322 tiger idle 00:00:00 14X.X.125.X
* vty 323 lion idle 00:00:00 14X.X.125.X
Thanks very much!