RIP what you need to remember

1.    The RIP process uses UDP port 520 
2.    The metric used by RIP is hop count, with 1 signifying a directly connected network of the advertising router and 16 signifying an unreachable network. 
3.    RIP sends periodic updates every 30 seconds  
4.    Default route can be advertised via: 
Static route 0.0.0.0, via redistribute static command.
default-information originate command advertises a default route even if a default route does not exist in the routing table. The route map must be standard access list.
ip default-network command provided the network address is a classfull network that router has a directly connected interface into that network AND the classfull network is in the local router’s routing table
5.    Unlike EIGRP the neighbor command under RIP process does not automatically suppress the sending of broadcast or multicast updates. The passive-interface command needed to get the same behavior/results. passive interface in RIP only stops the router sending updates out, it’ll still receive updates in from neighbors. If you have configured a static neighbor it’ll send unicast updates even if passive-interface has been configured.
6.    In RIP, route feedback may occur when generating summaries because RIP does not generate a route to Null0 like EIGRP, OSPF, and BGP. Possible solutions are static route to Null0, or distribute-list inbound filtering. 
7.    Supernet advertisement -advertising any network prefix less than its classfull major network- is not allowed via ip summary-address. Only one summary address can be configured for each classfull subnet. 
8.    The interface command ip rip triggered enables the router to send triggered updates only when there is a topology change. This command is only available on point-to-point serial links and must be configured on both ends of the link for it to work. 
9.   For secondary address on an interface disable ip split-horizon or no validate update source on the other/peer router. when connecting to non-Cisco devices you need to disable the holddown timer. timers basic 30 180 0 240
10.   IP split horizon checking is disabled by default for Frame Relay encapsulation to allow routing updates to go in and out of the same interface. An exception is the Enhanced Interior Gateway Routing Protocol (EIGRP) for which split horizon must be explicitly disabled.