intermachine "talk" problems

[Greg Woods]

 We have also seen the infinite "invitation check" and "protocol family not
supported" (the latter on the console) messages when trying to talk between
machines. Our VAX will talk to anyone, but we have some 68K based Integrated
Solutions machines (all running 4.2BSD) that will only talk to each other
and will not talk to the VAXes or the Pyramids. A fix won't help us much,
however, as we don't have sources on the I.S. systems, only on the VAXes.
I already tried bringing over the sources for talk and talkd from the VAXes
and recompiling them on the I.S. machines, but it doesn't change the behavior.

--Greg