ZyXEL Communications 2 Plus User Manual
Chapter 6 LAN Screens
ZyWALL 2 Plus User’s Guide
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6.3 DHCP
The ZyWALL can use DHCP (Dynamic Host Configuration Protocol, RFC 2131 and RFC
2132) to automatically assign IP addresses subnet masks, gateways, and some network
information like the IP addresses of DNS servers to the computers on your LAN. You can
alternatively have the ZyWALL relay DHCP information from another DHCP server. If you
disable the ZyWALL’s DHCP service, you must have another DHCP server on your LAN, or
else the computers must be manually configured.
2132) to automatically assign IP addresses subnet masks, gateways, and some network
information like the IP addresses of DNS servers to the computers on your LAN. You can
alternatively have the ZyWALL relay DHCP information from another DHCP server. If you
disable the ZyWALL’s DHCP service, you must have another DHCP server on your LAN, or
else the computers must be manually configured.
6.3.1 IP Pool Setup
The ZyWALL is pre-configured with a pool of IP addresses for the computers on your LAN.
See
See
for the default IP pool range. Do not assign your LAN computers
static IP addresses that are in the DHCP pool.
6.4 RIP Setup
RIP (Routing Information Protocol, RFC 1058 and RFC 1389) allows a router to exchange
routing information with other routers. RIP Direction controls the sending and receiving of
RIP packets. When set to Both or Out Only, the ZyWALL will broadcast its routing table
periodically. When set to Both or In Only, it will incorporate the RIP information that it
receives; when set to None, it will not send any RIP packets and will ignore any RIP packets
received.
RIP Version controls the format and the broadcasting method of the RIP packets that the
ZyWALL sends (it recognizes both formats when receiving). RIP-1 is universally supported;
but RIP-2 carries more information. RIP-1 is probably adequate for most networks, unless you
have an unusual network topology.
Both RIP-2B and RIP-2M send routing data in RIP-2 format; the difference being that RIP-
2B uses subnet broadcasting while RIP-2M uses multicasting. Multicasting can reduce the
load on non-router machines since they generally do not listen to the RIP multicast address
and so will not receive the RIP packets. However, if one router uses multicasting, then all
routers on your network must use multicasting, also.
By default, RIP Direction is set to Both and RIP Version to RIP-1.
routing information with other routers. RIP Direction controls the sending and receiving of
RIP packets. When set to Both or Out Only, the ZyWALL will broadcast its routing table
periodically. When set to Both or In Only, it will incorporate the RIP information that it
receives; when set to None, it will not send any RIP packets and will ignore any RIP packets
received.
RIP Version controls the format and the broadcasting method of the RIP packets that the
ZyWALL sends (it recognizes both formats when receiving). RIP-1 is universally supported;
but RIP-2 carries more information. RIP-1 is probably adequate for most networks, unless you
have an unusual network topology.
Both RIP-2B and RIP-2M send routing data in RIP-2 format; the difference being that RIP-
2B uses subnet broadcasting while RIP-2M uses multicasting. Multicasting can reduce the
load on non-router machines since they generally do not listen to the RIP multicast address
and so will not receive the RIP packets. However, if one router uses multicasting, then all
routers on your network must use multicasting, also.
By default, RIP Direction is set to Both and RIP Version to RIP-1.
6.5 Multicast
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 network-layer protocol used to establish
membership in a Multicast group - it is not used to carry user data. IGMP version 2 (RFC
2236) is an improvement over version 1 (RFC 1112) but IGMP version 1 is still in wide use. If
you would like to read more detailed information about interoperability between IGMP
version 2 and version 1, please see sections 4 and 5 of RFC 2236. The class D IP address is
used to identify host groups and can be in the range 224.0.0.0 to 239.255.255.255. The address
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 network-layer protocol used to establish
membership in a Multicast group - it is not used to carry user data. IGMP version 2 (RFC
2236) is an improvement over version 1 (RFC 1112) but IGMP version 1 is still in wide use. If
you would like to read more detailed information about interoperability between IGMP
version 2 and version 1, please see sections 4 and 5 of RFC 2236. The class D IP address is
used to identify host groups and can be in the range 224.0.0.0 to 239.255.255.255. The address