ZyXEL Communications P-2900-4HB User Manual

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Chapter 5 LAN Setup
P-2900-4HB User’s Guide
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5.4.4  RIP Setup
RIP Directions
The sending and receiving of RIP packets can occur in the following ways:
• 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.
RIP Versions
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 sends the routing data in RIP-2 format; the difference 
being that RIP-2B uses subnet broadcasting while RIP-2M uses multicasting.
5.4.5  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 224.0.0.0 is not 
assigned to any group and is used by IP multicast computers. The address 
224.0.0.1 is used for query messages and is assigned to the permanent group of 
all IP hosts (including gateways). All hosts must join the 224.0.0.1 group in order 
to participate in IGMP. The address 224.0.0.2 is assigned to the multicast routers 
group. 
The ZyXEL Device supports both IGMP version 1 (IGMP-v1) and IGMP version 2 
(IGMP-v2). At start up, the ZyXEL Device queries all directly connected networks