Question

Describe three different sources a router can use to put/maintain the information contained in the routing table.

Answer 1

Routing lTable

The routers have an inner memory called RAM. The all the information a routing table collect will be stored in RAM of routers. lA lrouting ltable lrecognizes lthe lpath lfor la lpacket lby llearning lthe lIP laddress and other related information from the table and forwards the packet to the desired target or network..

The lfollowing lare lthe lentities lhaving lin la lrouting ltable:

IP laddresses land lSubnet lmask lof lthe target lhost land lthe lnetwork
IP addresses of all those routers which are required to reach the target network.
Extrovert interface information

There lare lthree lvarious lprocedures lfor put/maintain lrouting ltable:

• Directly lconnected lsubnets
• Static lrouting
• Dynamic lrouting

Connected lRoutes: lIn lthe lideal lmode, lall lthe linterfaces lof lthe lrouters lwill lremain lin l‘down’ lstate. lSo lthe linterfaces lon lwhich luser lgoing lto limplement lany lconfiguration, lfirstly lchange lthe lstate lfrom l‘down’ lto l‘up’. lNext lstep lof setting lwill lbe lassigning lthe lIP laddresses lto lall linterfaces.

Now lthe lrouter lwill lbe lsmart lenough lto lroute lthe ldata lpackets lto la ldestination lnetwork lvia ldirectly lconnected lactive linterfaces. lThe lsubnets lare lalso ladded lin lthe lrouting ltable.

Static lRouting: lBy lusing lstatic lrouting, la lrouter lcan lgather lthe lroute lto lthe lfar lend lnetwork lthat lis lnot lphysically lor lstraightly lconnected lto lone lof lits linterfaces.

Routing lis ldone lmanually lbe lrunning la lparticular lcommand lwhich lis lglobally lused.

Dynamic iRouting: iThis itype iof irouting iworks iwith iat ileast ione itype iof irouting iprotocol iis ifacilitated iwith iit. iA irouting iprotocol iis ipracticed iby irouters iso ithat ithey ican ishare ithe irouting iinformation iamong ithem. iBy ithis iprocess, ieach iof ithe irouters iin ithe inetwork ican ilearn ithat iinformation iand iwill ideploy iit iin ibuilding iup itheir iown irouting itables.

Routing iprotocol iworks iin isuch ia iway iso ithat iif ia ilink igoes idown ion iwhich iit iwas irouting idata, iit idynamically ichange itheir ipath ifor irouting ipacket iwhich iin iturn imakes ithem ifault-resistant.

Dynamic irouting ialso idoesn’t ineed iany imanual iconfiguration iwhich isaves ithe itime iand iadministration iload.

We ionly ineed ito idefine ithe iroutes iand itheir icorresponding isubnets iwhich irouter iwill ibe iusing iand ithe irest iis itaken icare iby irouting iprotocols.