TELNET Problem Between TWO VM systems

[Don W.]

We are having problems telnetting from one z/VM system to another z/VM
system.   The network between the systems is through a netscreen that
creates a VPN tunnel. We can telnet from a pc on the vlan to each of the
host systems but we cannot telnet from one system to the other in either
direction. There is a vswitch on each z/VM system managing to OSA
connections. Both systems are running z/VM 5.1. We can ping between the
systems but not telnet...Any ideas?