timers and characteristics
Update: how often to send updates in seconds
Invalid: how many seconds, since seeing a valid update, to consider the route invalid, and placing the route into hold down
Hold Down: Once in hold down, how long (in seconds) to “not believe” any equal or less impressive (worse) route updates for routes that are in hold down
Flush: how many seconds, since the last valid update, until we throw that route in the trash (garbage collection for un-loved non-updated routes)
Hold Down: 180
The characteristics of RIPv2 follow:
- Distance-vector protocol.
- Uses UDP port 520.
- Classless protocol (support for CIDR).
- Supports VLSMs.
- Metric is router hop count.
- Maximum hop count is 15; infinite (unreachable) routes have a metric of 16.
- Periodic route updates sent every 30 seconds to multicast address 188.8.131.52.
- 25 routes per RIP message (24 if you use authentication).
- Supports authentication.
- Implements split horizon with poison reverse.
- Implements triggered updates.
- Subnet mask included in route entry.
- Administrative distance for RIPv2 is 120.
- Used in small, flat networks or at the edge of larger networks.