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three methods that can provide faster convergence when the network
topology changes and prevent most loops from occurring:
• Split Horizon – Never propagate routes back to an interface port from
which they have been acquired.
• Poison Reverse – Propagate routes back to an interface port from which
they have been acquired, but set the distance-vector metrics to infinity.
(This provides faster convergence.)
• Triggered Updates – Whenever a route gets changed, broadcast an
update message after waiting for a short random delay, but without
waiting for the periodic cycle.
Protocol Message Authentication
RIPv1 is not a secure protocol. Any device sending protocol messages
from UDP port 520 will be considered a router by its neighbors. Malicious
or unwanted protocol messages can be easily propagated throughout the
network if no authentication is required. RIPv2 supports authentication via
a simple password. When a router is configured to exchange
authentication messages, it will insert the password into all transmitted
protocol packets, and check all received packets to ensure that they contain
the authorized password. If any incoming protocol messages do not
contain the correct password, they are simply dropped.
Command Attributes
• VLAN – ID of configured VLAN (1-4093).
• Receive Version – The RIP version to receive on an interface.
- RIPv1: Accepts only RIPv1 packets.
- RIPv2: Accepts only RIPv2 packets.
- RIPv1 or RIPv2: Accepts RIPv1 or RIPv2 packets. (Default)
- Do Not Receive: Does not accept incoming RIP packets.
(The default depends on the setting specified under RIP / General
Settings, Global RIP Version: RIPv1 - RIPv1 or RIPv2 packets, RIPv2 -
RIPv2 packets)