Objectives: Use of conditional statementsUse of control statementsFunctional approach to design and build applicationIntroduction:Any application $($programming application$)$ runs sequentially unless the flow of theprogram takes to another sequence of execution using conditional and controlstatements. In this application, system administrator is given four options to choosefrom:a$)$ Type $$Routing$$ to route subnet on routerb$)$ Type $$Interface$$ to configure IP address to an interface of the devicec$)$ Type $$loopback$$ to configure loopback ID and assign IP address to theloopbackd$)$ Type $$End$$ to end applicationUser may choose any one option to change the flow of the application to execute therespective section of the application.Application execution:When application executes, following options are displayed:User may type $$Routing$,$Interface$,$Loopback$$ or $$End$.$ User may enter thesecommands in upper case letters or lower case letters or mixed format.If user enter an invalid choice $($one that is not defined through these four options$),$shown below:

Network Automation Lab $3$ Winter $2024$Here user entered choice $$DHCP$,$ which is not defined as choice here, the messagedisplayed is:$$Not valid choice of input option selected $....$ try again$$Now if user chooses option $$Routing$($case insensitive$),$ following is displayed:Note here, that you may enter value in upper case or lower case $($or mixed case$),$ theapplication asks user to enter the $$Autonomous Area Number$,$ user enters it and thenapplication asks for Sub$-$network address to be routed; user enters the sub$-$net routeand in the end application asks user to enter wildcard mask and user enters thewildcard mask.Application then displays the router configuration string.

Network Automation Lab $3$ Winter $2024$Application continues to display the menu option and now user enters $$LOOpback$($itcould be upper case or lower case or mixed case$).$ Following is displayed:User enters the respective information to configure Loopback ID $($with an IP address$)$and the application displays the configuration string to configure loopback ID $($with an IPaddress$).$ This is shown above.Now if the user chooses to configure interface IP address, user picks up $$Interface$$ andwhen $$Interface$$ option $($upper case or lower case or mixed case$)$ is selected, theapplication displays following information:

Network Automation Lab $3$ Winter $2024$User entered Eth $0/1$ as interface name, $192\mathrm{.}168\mathrm{.}200\mathrm{.}225$ as interface IP address and$255\mathrm{.}255\mathrm{.}255\mathrm{.}248$ as the interface mask.Application then displays the interface IP address configuration command with therespective values.In the end, if you plans to end the application, user chooses option $$End$($upper case orlower case or mixed case $$ it is case insensitive$).$ Once user enters $$EnD$,$ applicationdisplays message to that affect. This is shown below: