poll: protocol failure in circuit setup (Linux)

To tell the truth, I'm not sure it's the Linux issue only. It can be on other platforms as well.

If you saw something like this in telnet/ssh:

connect to address 1.2.3.4 port 544: Connection refused
Trying krb4 rsh...
connect to address 1.2.3.4 port 544: Connection refused
trying normal rsh (/usr/bin/rsh)
poll: protocol failure in circuit setup

then what probably causes it is firewall (iptables)
The quicky method is simply to shutdown the iptables firewall:
> su -
> services iptables stop

However, if you reboot your machine, the iptables will start and you will hit the problem again.

To permanently shut down the firwall service then, do the following:
> su -
> chkconfig --list iptables

- you will probably see this:
iptables 0:off 1:off 2:on 3:on 4:on 5:on 6:off

- then do:
> chkconfig --level 345 iptables off
> chkconfig --list iptables

- now you should see this:
iptables 0:off 1:off 2:on 3:off 4:off 5:off 6:off

Of course, for the current session, you still will have to call service iptables stop, but I guess you already know it.