The function of Switching is to switch data packets between devices on the same network (or same LAN - Local Area Network). The function of Routing is to Route packets between different networks (between different LANs - Local Area Networks). Switches operate at Layer 2 of the OSI Model (Datalink Layer).
When a node first starts, it only knows of its immediate neighbors and the direct cost involved in reaching them. (This information — the list of destinations, the total cost to each, and the next hop to send data to get there — makes up the routing table, or distance table.)
Switching is process to forward packets coming in from one port to a port leading towards the destination. When data comes on a port it is called ingress, and when data leaves a port or goes out it is called egress. A communication system may include number of switches and nodes. Data is then forwarded on that circuit.
Layer-2 switching is the process of using the hardware address of devices on a LAN to segment the network.
While a network switch can connect multiple devices and networks to expand the LAN, a router will allow you to share a single IP address among multiple network devices. In simpler terms, the Ethernet switch creates networks and the router allows for connections between networks.
Open Shortest Path First (OSPF)
Routing protocols can be classful or classless: Classful routing protocols DO NOT send the subnet mask along with their updates. Classless routing protocols DO send the subnet mask along with their updates.
There are 3 types of routing:
- Static routing – Static routing is a process in which we have to manually add routes in routing table.
- Default Routing – This is the method where the router is configured to send all packets towards a single router (next hop).
- Dynamic Routing –
Routing protocols provide information to routing algorithms in the form of variables or metrics. Routing algorithms, on the other hand, provide routing protocols with the best path for the router to send data.
In computer networking a routing table, or routing information base (RIB), is a data table stored in a router or a network host that lists the routes to particular network destinations, and in some cases, metrics (distances) associated with those routes.
HOP counts refer to the number of devices, usually routers, that a piece of data travels through. Each time that a packet of data moves from one router (or device) to another — say from the router of your home network to the one just outside your county line — that is considered one HOP.
These dynamic routing protocols are commonly broken into two major categories: Interior routing protocols or IGP (Interior Gateway Protocols) and Exterior routing protocols or EGP (Exterior Gateway Protocols).
To configure dynamic routing: Choose Networking > Routing > Dynamic Routing. To configure how the router sends and receives RIP packets, choose the RIP direction: None—The router neither broadcasts its route table nor does it accept any RIP packets from other routers.
Overview of Dynamic Routing Gateways. You can think of a DRG as a virtual router that provides a path for private traffic (that is, traffic that uses private IPv4 addresses) between your VCN and networks outside the VCN's region.
0.0/0 pointing to your ISP. You do not need the dynamic routing. Example 2: If you have single link between two locations and you have only 2 networks in location A and 4 networks in location B, use can still use static routing (no big administrative overhead).
Dynamic routing, also called adaptive routing, is a process where a router can forward data via a different route or given destination based on the current conditions of the communication circuits within a system.
A primary benefit of dynamic routing protocols is that routers exchange routing information when there is a topology change. This exchange allows routers to automatically learn about new networks and also to find alternate paths when there is a link failure to a current network.
The chief advantages of dynamic routing over static routing are scalability and adaptability. A dynamically routed network can grow more quickly and larger, and is able to adapt to changes in the network topology brought about by this growth or by the failure of one or more network components.
Dynamic routing protocols exist to discover the network, maintain routing tables, and calculate the best path.
The dynamic routing protocol that is the most different from all the others is the Border Gateway Protocol (BGP). BGP also can be configured to learn either full or partial routing tables to make better routing decisions based on the optimal outbound internet path to the destination router.
Routing Information Protocol (RIP) is a dynamic routing protocol which uses hop count as a routing metric to find the best path between the source and the destination network. It is a distance vector routing protocol which has AD value 120 and works on the application layer of OSI model. RIP uses port number 520.
