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Routers - August 20, 2008, 17:00 pm by Rajmeet Ghai
What are the basic components of routers?
Answer
Components of Router
Internal components:
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ROM:- Used to store the routers bootstrap details, operating system software.
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Flash memory: - holds the operating systems images. The content is retained
when the router is restarted.
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RAM: - Used to store the Routing tables, configuration files, caching and
buffering details. Content is lost when lost router is switched off or
restarted.
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NVRAM:- Stores the routers startup config files. Data is non volatile.
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Network interfaces to connect router to network.
External components:
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Virtual terminals: For accessing routers
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Network management stations
What is Routing table?
Answer
A routing table stores the routes of the various nodes in a network.
Nodes can be any electronic device connected to the network. The table is
usually stored in a router or the network computer as a database or file. This
information helps to fond the best possible path. The routing table has at
least 3 fields: the destination network id, cost of the path, next hop or
address to send the packet.
What is Routing Protocols?
Answer
Routing protocols are used to assist in achieving the basic purpose of
routing. They specify the routers the method to communicate with each other.
They help the routers select the best possible path between nodes. There are
different types of protocols such as link-state routing protocols, path vector
protocols and distance vector routing protocols. These protocols prevent
routing loops to form or break if formed already. They help to decide preferred
routes from a sequence of hop costs.
What is Distance Vector Routing Protocols?
Answer
The main goal of Distance Vector Routing Protocols Is to find out the
best path for he data packet to reach the destination. Distance here could be
the hops. The three different types of Distance Vector routing protocols
include:- Routing Information Protocol (RIP v1 and v2) and Interior Gateway
Routing Protocol. The protocol is easy to manage however not well scalable.
The Distance Vector protocol initially prepares a Routing table which is shared
with other routers. This routing table is shared between routers present in the
same network. A new routing table is prepared when some new information is
received from some other router. Now, the bad routing paths are removed keeping
only the smallest hop paths. This new table is then communicated to other
routers.
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