IBM RackSwitch G8000 Application Manual page 215

© Copyright IBM Corp. 2011
Multicast
RIPv2 messages use IPv4 multicast address (224.0.0.9) for periodic broadcasts.
Multicast RIPv2 announcements are not processed by RIPv1 routers. IGMP is not
needed since these are inter-router messages which are not forwarded.
To configure RIPv2 in RIPv1 compatibility mode, set multicast to disable, and set
version to both.
Default
The RIP router can listen and supply a default route, usually represented as IPv4
0.0.0.0 in the routing table. When a router does not have an explicit route to a
destination network in its routing table, it uses the default route to forward those
packets.
Metric
The metric field contains a configurable value between 1 and 15 (inclusive) which
specifies the current metric for the interface. The metric value typically indicates the
total number of hops to the destination. The metric value of 16 represents an
unreachable destination.
Authentication
RIPv2 authentication uses plaintext password for authentication. If configured using
Authentication password, then it is necessary to enter an authentication key value.
The following method is used to authenticate an RIP message:
• If the router is not configured to authenticate RIPv2 messages, then RIPv1 and
unauthenticated RIPv2 messages are accepted; authenticated RIPv2 messages
are discarded.
• If the router is configured to authenticate RIPv2 messages, then RIPv1
messages and RIPv2 messages which pass authentication testing are accepted;
unauthenticated and failed authentication RIPv2 messages are discarded.
For maximum security, RIPv1 messages are ignored when authentication is
enabled; otherwise, the routing information from authenticated messages is
propagated by RIPv1 routers in an unauthenticated manner.
Chapter 18. Routing Information Protocol
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