/Static Routing Vs Dynamic Routing

Static Routing Vs Dynamic Routing

If you’re not familiar with “routing” and “routing tables” please refer to this topic before you continue : http://blog.catreloaded.org/2010/12/routing-tables/
Static routing , Isn’t really a routing protocol all you need –as explained before- is to add the routes and you’re good to go , doing this in only convenient with small networks
*surprise* It wont change unless a human change it , so it wont handle any changes in your network –if a device is updated or something- you’ll need to reconfigure the route.
Dynamic routing :
Each router runs a routing daemon which allows it to communitcate with other routers in the network and transfere it’s routing table to other routers . using this information they’re able to decide an accurate picture of the network and calculate the best route to every destination on the network,Then this data will be stored into the routing table in the kernel.

This is implemented in two algorithms (vector distance , Link state)
Briefly , in vector distance algorithm each router communicates with it’s neighbors , a receiving router will then updated it’s routing table and transfere it to the next neighbour which is really slow.
While in Link state algorithm each router multicasts it’s table to every router in the network , that’s how every router will be able to calculate the best route for every destination on the network , however it’s much more complex.

Based on these algorithms several protocols have been designed to implement them they include :
-RIP (Route Information Protocol)
-OSPF(Open Shortest Path first) which is used for complex unstable networks
-BGP(Border Gateway Protocol) the standard protocol for the internet

These protocols are Implemnted in what I mentioned before , the routing daemons most Unix systems has two or three daemons which are :
1-routed : The oldest daemon ,It implements RIP protocol only which doesn’t need any configuration the only thing you need to do is set IP forwarding on
# echo 1 > /proc/sys/net/ipv4/ip_forward
Or to make this perminant :
Edit /etc/sysctl.conf
2-gated : A commercial daemon ,It implements every routing protocol which is really complex
3-Zebra : The open source response to gated
routing daemon management is usually a task done by someone other than the system admin but I think I’ll cover that part anyways later isA.