RIP is a distance-vector routing protocol that uses hop count as its routing metric. RIP versions include RIPv1 for IPv4, RIPv2 for classless routing and authentication with IPv4, and RIPng which extends RIPv2 to support IPv6 routing. Key attributes of RIP include using the Bellman-Ford algorithm, storing routes in tables with a maximum metric of 15 hops, and sending periodic full routing table updates every 30 seconds. RIP configuration involves enabling RIP on interfaces, modifying timers, and configuring authentication and route summarization.

1. RIP packetlife.net
RIP Implementations Attributes
RIPv1 Type Distance Vector
Original RIP implementation, limited to classful routing
Algorithm Bellman-Ford
(obsolete)
RIPv2 Admin Distance 120
Introduced support for classless routing, authentication, Metric Hop count (max 15)
triggered updates, and multicast announcements (RFC 2453)
Standard RFCs 2080, 2453
RIPng (RIP Next Generation)
Extends RIPv2 to support IPv6 routing (RFC 2080); functions Protocols IPv4, IPv6
very similarly to RIPv2 and is subsequently as limited Transport UDP
Protocols Comparison Authentication Plaintext, MD5
RIPv1 RIPv2 RIPng Multicast IP 224.0.0.9/FF02::9
IP IPv4 IPv4 IPv6
Terminology
Admin Distance 120 120 120
Split Horizon
UDP Port 520 520 521 A rule that states a router may not advertise a route
back to the neighbor from which it was learned
Classless No Yes Yes
Route Poisoning
Adv. Address Broadcast 224.0.0.9 FF02::9
When a network becomes unreachable, an
Authentication None Plain, MD5 None update with an infinite metric is generated to
explicitly advertise the route as unreachable
RIPv2 Configuration
Poison Reverse
A router advertises a network as unreachable
! Enable RIPv2 IPv4 routing
through the interface on which it was learned
router rip
version 2
Timer Defaults
! Disable RIPv2 automatic summarization Update 30 sec Flush 240 sec
no auto-summary
Invalid 180 sec Hold-down 180 sec
! Designate RIPv2 interfaces by network
network network RIPv2 Interface Configuration
! Identify unicast-only neighbors ! Configure manual route summarization
neighbor IP-address ip summary-address rip network mask
! Originate a default route ! Enable MD5 authentication (RIPv2 only)
default-information originate ip rip authentication mode md5
ip rip authentication key-chain key-chain
! Designate passive interfaces
passive-interface {interface | default} RIPng Interface Configuration
! Modify timers ! Enable RIPng on the interface
timers basic update invalid hold flush ipv6 rip name enable
RIPng Configuration ! Configure manual route summarization
ipv6 rip name summary-address prefix
! Enable IPv6 routing
ipv6 unicast-routing Troubleshooting
! Enable RIPng IPv6 routing show ip[v6] protocols
ipv6 router rip name
show ip[v6] rip database
! Toggle split-horizon and poison-reverse show ip[v6] route rip
[no] split-horizon
[no] poison-reverse debug ip rip { database | events }
! Modify timers debug ipv6 rip [interface]
timers basic update invalid hold flush
by Jeremy Stretch v1.1