Listing 8

# Example using netacl to switch telnet service
netacl-in.telnetd: permit-hosts 127.0.0.1 -exec /usr/sbin/in.telnetd
netacl-in.telnetd: permit-hosts bastion.host.internal.net -exec /usr/sbin/in.telnetd
netacl-in.telnetd: permit-hosts * -exec
/usr/local/etc/tn-gw

# Example tn-gw config
tn-gw: deny-hosts unknown
tn-gw: permit-hosts .trusted.external.net -dest compute.server.internal.net
tn-gw: permit-hosts .internal.net -passok
tn-gw: permit-hosts * -auth -dest !bastion.host !127.0.0.1
tn-gw: authserver localhost 7777
tn-gw: denial-msg /usr/local/etc/telnet-deny.txt
tn-gw: welcome-msg /usr/local/etc/telnet-welcome.txt
tn-gw: help-msg /usr/local/etc/telnet-help.txt