What is Routing Protocol?

 

A routing protocol is a set of rules and procedures that routers
use to exchange information about network topology and determine the best path
for forwarding packets. Routing protocols are used to build and maintain
routing tables, which contain information about the reachability of different
network destinations.

 

There are two main types of routing protocols:

 

Distance-vector
protocols: These protocols determine the best path to a destination by
considering the number of hops (or “distance”) to the destination.
Examples include RIP (Routing
Information Protocol) and IGRP
(Interior Gateway Routing Protocol).

Link-state
protocols: These protocols determine the best path to a destination by
considering the entire topology of the network. Examples include OSPF (Open
Shortest Path First) and IS-IS (Intermediate System to Intermediate System)

 

Each routing protocol has its own advantages and disadvantages,
and the choice of which protocol to use depends on the specific requirements of
the network. Some common factors to consider when choosing a routing protocol
include scalability, ease of configuration, and support for different types of
network environments.

 

OSPF vs RIP vs EIGRP

 

OSPF (Open Shortest Path First), RIP (Routing Information
Protocol), and EIGRP (Enhanced Interior Gateway Routing Protocol) are all
routing protocols used in IP networks.

OSPF is a
link state routing protocol that uses a shortest path first algorithm. It is
considered a more advanced and complex routing protocol compared to RIP and
EIGRP. OSPF is typically used in enterprise networks and supports
variable-length subnet masks (VLSMs), making it efficient in large and complex
networks. It also has a larger administrative distance than the other two
protocols.

RIP is a
distance-vector routing protocol that uses a hop count metric to determine the
best path to a destination. It is a simpler protocol compared to OSPF and
EIGRP, and is typically used in smaller networks. However, it has a maximum hop
count limit of 15, which makes it less suitable for larger networks.

EIGRP is a
Cisco proprietary advanced distance-vector routing protocol that uses metrics
based on bandwidth, delay, reliability, and load. EIGRP has many features
similar to OSPF, but it is considered more efficient and faster at convergence.
It also supports VLSM and it is considered a better option than RIP in larger
networks. EIGRP also uses a hybrid of distance-vector and link-state routing,
which makes it more versatile than RIP and OSPF.

In summary, OSPF is considered a more advanced and complex routing
protocol and is typically used in enterprise networks, EIGRP is a Cisco
proprietary advanced distance-vector routing protocol, considered more
efficient and faster at convergence, and RIP is a simpler protocol typically
used in smaller networks.

The
main differences between them are:

Routing
algorithm: EIGRP and OSPF are both advanced routing protocols, while RIP is
a simpler distance-vector protocol. OSPF is a link-state routing protocol, meaning
that each router in the network has knowledge of the entire topology of the
network. EIGRP is a Cisco proprietary protocol and uses a hybrid of
distance-vector and link-state routing, which makes it more versatile than RIP
and OSPF. RIP uses a hop count metric to determine the best path to a
destination.

Scalability:
OSPF and EIGRP are considered more suitable for large and complex networks, as
they support variable-length subnet masks (VLSMs) and have larger
administrative distances than RIP. RIP has a maximum hop count limit of 15,
which makes it less suitable for larger networks.

Convergence:
EIGRP is considered more efficient and faster at convergence than OSPF and RIP,
as it uses a Diffusing Update Algorithm (DUAL) to quickly calculate the best path
to a destination. OSPF and RIP may take longer to converge in large networks.

Support:
EIGRP is a Cisco proprietary protocol and only works with Cisco routers, while
OSPF and RIP are open standards and are supported by most routers.

In summary, EIGRP is a Cisco proprietary advanced distance-vector
routing protocol that uses metrics based on bandwidth, delay, reliability, and
load, OSPF is a link-state routing protocol that uses a shortest path first
algorithm and typically used in enterprise networks, and RIP is a simpler
protocol typically used in smaller networks and it has a maximum hop count
limit of 15, which makes it less suitable for larger networks.