Notes:

auto-summary in RIP affects what is advertised, but not the local RIB.
Preventing route feedback: Prevent router feedback (RIP) with static route to null0 or distribute-list (IN) on originating router.

interface> ip rip advertise (interval different than the global)

default sent out specific interface: use route-map that sets interface and default-information originate.
DON'T FORGET ABOUT ROUTE FEEDBACK IN RIP!

ACL to filter even/odd octets:

ip access permit 0.0.1.0 255.255.254.255 : permit 3rd octet odd only
ip access permit 0.0.0.0 255.255.254.255 : permit 3rd octet even only

Track route with route-map for default route injection. 

Reliable Conditional Default Routing:

R1:
track 1 ip sla 1 reachability router rip
 version 2
 default-information originate route-map SLA ip route 169.1.1.1 255.255.255.255 Null0 name BOGUS track 1

ip prefix-list SLA seq 5 permit 169.1.1.1/32
ip sla 1
 icmp-echo 204.12.17.254 source-interface FastEthernet0/0
ip sla schedule 1 life forever start-time now
!
route-map SLA permit 10
 match ip address prefix-list SLA

RIP Unicast updates:
neighbor statement and passive interface command.
Without passive interface, broadcast and multicast updates will continue to be sent. RIP Broadcast Update: interface> ip rip v2-broadcast

RIP Triggered Updates: interface> ip rip triggered  RIP Source Validation: (Do I have a path bath in the RIB?) Router RIP no validate-update-source (to disable check)