D-Link DSR-150N DSR-150 User Manual - Page 103

Unified Services Router Figure 62 : Pas s through options for VPN tunne ls User Manual 5.8 Application Rules Advanced > Application Rules > Application Rules Application rules are als o referred to as p ort triggering . This feature allows devices o n t h e LA N o r DM Z t o req u es t o n e o r mo re p o rt s t o b e fo rward ed t o t h em. Po rt t rig g erin g wait s fo r an o u t b o u n d req u es t fro m t h e LA N/ DM Z o n o n e o f t h e d efin ed o u t g o ing p ort s, an d t h en o pens an in co min g p ort fo r t h at s pecified t y pe o f t raffic. This can b e t h o u g h t o f as a fo rm o f d y n amic p o rt fo rward in g wh ile an ap p licat io n is t ran s mit t in g d at a o v er t h e o p en ed o u t g o in g o r in co min g p o rt (s ). Po rt t rig g erin g ap plicat ion ru les are mo re flexib le t h an s t at ic p o rt fo rward in g t h at is an available option when configuring firewall rules . This is becaus e a port triggering ru le d o es n o t h ave t o referen ce a s p ecific LA N IP o r IP ran g e. A s well p o rt s are n o t left open when not in us e, thereby providing a level of s ecurity that port forwarding does not offer.  Po rt t rig g erin g is n o t ap p ro p riat e fo r s erv ers o n t h e LA N, s in ce t h ere is a d ep en d en cy o n t h e LA N d ev ice makin g an o u t g o in g co n n ect io n b ef o re in co min g ports are opened. So me ap p licat io n s req uire t h at wh en ext ern al d ev ices co n n ect t o t h em, t h ey receiv e d at a o n a s p ecific p o rt o r ran g e o f p o rts in o rd er t o fu n ct ion p rop erly . Th e ro u ter mu s t s en d all in co min g d at a fo r t h at ap p licat io n o n ly o n t h e req u ired p o rt o r ran g e o f p o rts. Th e ro u t er h as a lis t o f co mmo n ap p licat io n s and g ames wit h co rresp ond ing o ut bou n d an d in b o u nd p ort s t o o p en. Yo u can als o sp ecify a p o rt t rig gerin g ru le b y d efin ing t h e t y p e o f t raffic (TCP o r UDP) an d t h e ran g e o f in co min g an d o u t g o in g p o rt s t o o p en when enabled. 101