ZyXEL Communications P-334WT Support Notes page 175

Configure P-334WT Behind a NAT Router
Some tips for this application:
1. The NAT router must support to pass through IPSec protocol. Only ESP tunnel mode is possible
to work in NAT case. If the NAT router is ZyXEL NAT router (P300 series, P643, P642, or
P202) supporting IPSec pass through, default port and the P-334WT WAN IP must be configured
in their SUA/NAT Server Table.
2. WAN IP of the NAT router is the tunneling endpoint for this case, not the WAN IP of P-334WT.
3. If firewall is turned on in P-334WT, you must forward IKE port in Internet interface.
4. If NAT are also enabled in P-334WT, NAT server is required for non-secure connections, NAT
server is not required for secure connections and the phyical private IP is used.
host----P-334WT----NAT Router----Internet----Secure host
\
\
Non-secure host