RIPv1:  Broadcasts updates every 30 seconds to the address 255.255.255.255.  RIPv1 is a classful protocol, and it does not recognize VLSM, nor does it carry subnet masking information in its routing updates.  Update contains entire RIP routing table. Uses Bellman-Ford algorithm.  Allows equal-cost load-balancing by default.  Max hop count is 15.  Does not support clear-text or MD5 authentication of routing updates. Updates carry 25 routes maximum.

RIPv2:  Multicasts updates every 30 seconds to the address 224.0.0.9.  RIPv2 is a classless protocol, allowing the use of subnet masks.  Update contains entire RIP routing table.  Uses Bellman-Ford algorithm. Allows equal-cost load-balancing by default.  Max hop count is 15.  Supports clear-text and MD5 authentication of routing updates. Updates carry 25 routes maximum.

IGRP:  Broadcasts updates every 90 seconds to the address 255.255.255.255.  IGRP is a Cisco-proprietary protocol, and is also a classful protocol and does not recognize subnet masking.  Update contains entire routing table. Uses Bellman-Ford algorithm. Equal-cost load-balancing on by default; unequal-cost load-sharing can be used with the variance command.  Max hop count is 100.  

EIGRP:  Multicasts full routing table only when an adjacency is first formed.  Multicasts updates only when there is a change in the network topology, and then only advertises the change.  Multicasts to 224.0.0.10 and allows the use of subnet masks.  Uses DUAL routing algorithm.  Unequal-cost load-sharing available with the variance command.