1. Data Communication and Network Oral Test
Let’ssay the networkisjustfinishedinstallation.Sowe wanttotestthe network.We have tosent
PINGfrom PC1 to the serverinorderto make sure the connectionisworking.The PC1ispersonal
computerwithWindowsXPOS.
STEP 1
WhenpC1 type PING,for instance:
PING192.168.30.1  it isthe addressof SRV1.In thiscase the addressof PC1 is 192.168.10.1. We
call it differentsubnet.
PC1 starts buildingthe packet.The packetwon’tleave PC1if itisnot completedwithMACaddress
source and destination,IPaddresssource anddestination.
MAC addressof PC1 : A1 : B1 : C1 : D1 : E1 : F1  the source
MAC addressRouter : A5 : B5 : C5 : D5 : E5 : F5  the destination
IP addressof PC1 : 192.168.10.1  source
IP addressSRV : 192.108.30.1  final destination
 The packet can leave nowbecause itiscompleted.
STEP 2
The packet isnowenteredportnumber1, switch1. Defaultgateway(type) router:E0 
192.168.10.100  same subnetmaskwithPC1.
The packet enteredE0,the routercheckedMAC addressdestinationIPdestination.
The router hascapabilityof determiningwhichnetworkislocal,whichisremote.
The router checksthe IP addressdestinationandfoundthe subnetmaskisdifferent.
E0
E0
S0
S0

2.  Same  block
 Different pass
STEP 3
Routerconsultsthe routingtable.The routingtable hasconfiguredbyadminusingstaticrouting.So
the table consistnexthoprouter/IPaddress:192.168.30.0. The outgoinginterface isS0because
adminconfigure it.
Routerfoundthe outputexitinterface isS0.Because router1and router2alreadyconfiguredby
staticrouting,the packetpassed to router2E0. The E0 isdefaultnetworkgatewayof SRV1.
STEP 4
Because the router2is directlyconnectedtoSRV throughswitch2finallythe packetarrivedatSRV1
and SRV1 preparingtoresponse the PINGtest.