9.2.2 Packet Tracer - Configure OSPF Advanced Features (Answers)

R1(config)# interface s0/0/0
R1(config-if)# ip ospf hello-interval 15
R1(config-if)# ip ospf dead-interval 60

R1(config-if)# bandwidth 64

! ==============================================================
!--- 9.2.2 Packet Tracer - Configure OSPF Advanced Features
!--- ANSWER SCRIPT FOR ROUTER R1
!--- Usage: copy this whole file and paste it into the R1 terminal (start at the R1> prompt). Every line beginning with "!" is a comment; IOS ignores it, so pasting a comment by accident is harmless.
!--- Scope: OSPF is already fully configured and working on all three
!--- routers per the activity's own Scenario note - this script only
!--- tweaks the R1-R2 serial link's OSPF timers and cost metric.
! ==============================================================

enable
configure terminal

! --------------------------------------------------------------
!--- Part 1, Step 2: Adjust the OSPF hello/dead timers on the link to R2.
!--- Both ends must match, or the adjacency drops once R1's values
!--- differ from R2's remaining defaults (hello 10 / dead 40).
! --------------------------------------------------------------

interface Serial0/0/0

!--- Longer hello interval - fewer keepalives, slower failure detection.
 ip ospf hello-interval 15

!--- Dead interval kept at 4x hello (IOS convention), just scaled up.
 ip ospf dead-interval 60

! --------------------------------------------------------------
!--- Part 1, Step 3: Lower the link's OSPF cost by inflating its
!--- bandwidth statement, so R1 stops preferring the path through R2
!--- to reach the Internet/web server.
! --------------------------------------------------------------

!--- This only changes the OSPF cost metric (cost = reference-bw /
!--- bandwidth); it does not touch the interface's real clock rate.
 bandwidth 64
 exit

end

! --------------------------------------------------------------
!--- Save the configuration to NVRAM. (Press Enter when prompted for the destination filename.)
! --------------------------------------------------------------
copy running-config startup-config


! ==============================================================
!--- Verification:
!---   show ip ospf interface serial0/0/0  -> Hello 15, Dead 60, BW 64 Kbit
!---   show ip ospf neighbor               -> adjacency with R2 stays FULL (only after R2 is updated to match)
!---   traceroute 64.100.1.2 (from PC1)    -> path now goes via R3 instead of R2
!--- Note: until R2's timers are updated to match (this script's
!--- companion R2 script), the R1-R2 adjacency will drop after roughly
!--- one dead-interval (60 sec) because R2 is still sending Hellos
!--- every 10 sec / expecting a reply within 40 sec.
! ==============================================================

! ==============================================================
!--- 9.2.2 Packet Tracer - Configure OSPF Advanced Features
!--- ANSWER SCRIPT FOR ROUTER R2
!--- Usage: copy this whole file and paste it into the R2 terminal (start at the R2> prompt). Every line beginning with "!" is a comment; IOS ignores it, so pasting a comment by accident is harmless.
!--- Scope: OSPF is already fully configured and working on all three
!--- routers per the activity's own Scenario note - this script only
!--- matches R1's new OSPF timers on the shared serial link.
! ==============================================================

enable
configure terminal

! --------------------------------------------------------------
!--- Part 1, Step 2b: Match R1's hello/dead timers on the same link.
!--- OSPF requires the hello and dead intervals to be identical on
!--- both ends of a link, or the adjacency won't come up (or will drop
!--- if it was already up).
! --------------------------------------------------------------

interface Serial0/0/0
 ip ospf hello-interval 15
 ip ospf dead-interval 60
 exit

!--- No bandwidth change here - only R1's path preference away from R2
!--- is being adjusted in this activity, so R2 keeps its default
!--- bandwidth statement on this interface.

end

! --------------------------------------------------------------
!--- Save the configuration to NVRAM. (Press Enter when prompted for the destination filename.)
! --------------------------------------------------------------
copy running-config startup-config


! ==============================================================
!--- Verification:
!---   show ip ospf interface serial0/0/0  -> Hello 15, Dead 60 (matches R1)
!---   show ip ospf neighbor               -> adjacency with R1 stays FULL
!---   ping / traceroute from PC1, PC2, PC3 to 64.100.1.2  -> all still succeed
! ==============================================================