I have a machine with the familiar three-legged firewall setup.

sis0 is connected to a DSL router (Cisco 678). It has the public IP
(1.2.3.4).

sis1 is connected to a hub to which the client machines connect. Its
IP is 192.168.0.1. The machines connect to and through it with no
problem. They have IP addresses of 192.168.0.2 . . . and have their
default gateway set as 192.168.0.1. I have a nat rule for them, etc.

sis2 is connected to my server. Its IP is 192.168.1.1. The server's
is 192.168.1.2 with default gateway of 192.168.1.1.
I
I cannot, for love or money, connect to the server. Both ping and SSH
just hang. I know the firewall ruleset isn't a problem because I
changed it to "pass all" (temporarily) and had similar problems.
Interestingly, 192.168.1.2 does come up in "route show."

Any suggestions/ideas?