@ avronius
Quote:
Please post the information about from the DSL-320T (LAN and WAN IP addresses)
Please identify which interfaces are attached to the DSL-320T, which are attached to the other internal switch.
please see the OPs first post - he already explained it with a nice picture
and from that netstat -rn - that is very obvious the rtls1 is the WAN (modem facing) interface, and rtls0 is the LAN side. the default gateway and resolv.conf/nsswitch.conf were also correct.
all he needs to do was only NAT.
HTH.