If the Primary and Secondary DNS Server fields in the LAN Setup screen are not specified, for instance, left as 0.0.0.0, the ZyXEL Device tells the DHCP clients that it itself is the DNS server. When a computer sends a DNS query to the ZyXEL Device, the ZyXEL Device forwards the query to the real DNS server learned through IPCP and relays the response back to the computer.
Please note that DNS proxy works only when the ISP uses the IPCP DNS server extensions. It does not mean you can leave the DNS servers out of the DHCP setup under all circumstances. If your ISP gives you explicit DNS servers, make sure that you enter their IP addresses in the LAN Setup screen. This way, the ZyXEL Device can pass the DNS servers to the computers and the computers can query the DNS server directly without the ZyXEL Device’s intervention.
7.1.5 RIP SetupRIP (Routing Information Protocol) allows a router to exchange routing information with other routers. The RIP Direction field controls the sending and receiving of RIP packets. When set to:
•Both - the ZyXEL Device will broadcast its routing table periodically and incorporate the RIP information that it receives.
•In Only - the ZyXEL Device will not send any RIP packets but will accept all RIP packets received.
•Out Only - the ZyXEL Device will send out RIP packets but will not accept any RIP packets received.
•None - the ZyXEL Device will not send any RIP packets and will ignore any RIP packets received.
The Version field controls the format and the broadcasting method of the RIP packets that the ZyXEL Device sends (it recognizes both formats when receiving).
Both
Traditionally, IP packets are transmitted in one of either two ways - Unicast (1 sender - 1 recipient) or Broadcast (1 sender - everybody on the network). Multicast delivers IP packets to a group of hosts on the network - not everybody and not just 1.
IGMP (Internet Group Multicast Protocol) is a
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