Dynamic routing

Dynamic routing performs the same function as static routing except it is more robust. Static routing allows routing tables in specific routers to be set up in a static manner so network routes for packets are set. If a router on the route goes down the destination may become unreachable. Dynamic routing allows routing tables in routers to change as the possible routes change. There are several protocols used to support dynamic routing including RIP and OSPF.

Routing cost
Counting route cost is based on one of the following calculations:
Hop count - How many routers the message must go through to reach the recipient.
Tic count - The time to route in 1/18 seconds (ticks).
Dynamic routing protocols do not change how routing is done. They just allow for dynamic altering of routing tables.There are two classifications of protocols:
IGP - Interior Gateway Protocol. The name used to describe the fact that each system on the internet can choose its own routing protocol. RIP and OSPF are interior gateway protocols.
EGP - Exterior Gateway Protocol. Used between routers of different systems. There are two of these, the first having the same name as this protocol description:
EGP - Exterior Gateway Protocol
BGP - Border Gateway Protocol.
The daemen "routed" uses RIP. The daemon "gated" supports IGP's and EGP's.