10.8.1 Packet Tracer - Configure CDP, LLDP, and NTP (Answers)

HQ(config)#no cdp run

HQ(config)#lldp run

HQ(config)#interface GigabitEthernet0/0/0
HQ(config-if)#no lldp transmit
HQ(config-if)#lldp receive

HQ(config-if)#interface GigabitEthernet0/0/1
HQ(config-if)#no lldp transmit
HQ(config-if)#lldp receive

Branch(config)#cdp run

Branch#show cdp neighbors detail

Device ID: BR-SW-1
Entry address(es): 
  IP address : 192.168.4.250
Platform: cisco 2960, Capabilities: Switch
Interface: GigabitEthernet0/0/0.10, Port ID (outgoing port): GigabitEthernet0/1
Holdtime: 170

Branch#ssh -l admin 192.168.4.250

Password: SW1admin#

BR-SW-1>

BR-SW-1>enable
Password: SW1EnaAccess#

BR-SW-1#show cdp neighbors detail

Device ID: BR-SW-2
Entry address(es): 
  IP address : 192.168.4.253
Platform: cisco 2960, Capabilities: Switch
Interface: GigabitEthernet0/2, Port ID (outgoing port): GigabitEthernet0/2
Holdtime: 124
---------------------------

Device ID: BR-SW-3
Entry address(es): 
  IP address : 192.168.4.254
Platform: cisco 2960, Capabilities: Switch
Interface: FastEthernet0/24, Port ID (outgoing port): GigabitEthernet0/1
Holdtime: 124

BR-SW-1#ssh -l admin 192.168.4.253
Password: 
BR-SW-2>enable
Password: 
BR-SW-2#configure terminal
BR-SW-2(config)#interface fa0/1
BR-SW-2(config-if)#no cdp enable
BR-SW-2(config-if)#end

BR-SW-2#ssh -l admin 192.168.4.254
Password: 
BR-SW-3>enable
Password: 
BR-SW-3#configure terminal
BR-SW-3(config)#interface fa0/1
BR-SW-3(config-if)#no cdp enable
BR-SW-3(config-if)#end

HQ(config)#ntp server 192.168.1.254

! ==============================================================
!--- 10.8.1 Packet Tracer - Configure CDP, LLDP, and NTP
!--- ANSWER SCRIPT FOR ROUTER HQ
!--- Usage: from the console (or CLI tab) on HQ, enter privileged EXEC mode with "enable",
!--- then paste this whole file. Every line beginning with "!" is a comment; IOS ignores it.
!--- HQ switches entirely from CDP to LLDP, configured to only RECEIVE from its two
!--- switches (never transmit back to them) - a one-way flow of discovery info toward HQ.
! ==============================================================

enable
configure terminal

! --------------------------------------------------------------
!--- Enable LLDP globally, then set both switch-facing links to receive-only.
!--- "lldp receive" is included explicitly even though it's on by default once LLDP itself
!--- is running - harmless, just makes the intent explicit in the saved config.
! --------------------------------------------------------------
lldp run

interface GigabitEthernet0/0/0
 no lldp transmit
 lldp receive
exit

interface GigabitEthernet0/0/1
 no lldp transmit
 lldp receive
exit

! --------------------------------------------------------------
!--- Disable CDP entirely on HQ - this network standardizes on LLDP instead.
! --------------------------------------------------------------
no cdp run

! --------------------------------------------------------------
!--- Point HQ at the NTP server on its own LAN.
! --------------------------------------------------------------
ntp server 192.168.1.254

end

! ==============================================================
!--- Verification:
!---   HQ# show lldp neighbors -> HQ-SW-1 and HQ-SW-2 both appear (HQ is receiving from
!---   both); neither switch would see HQ if you checked their own "show lldp neighbors"
!---   HQ# show cdp -> "% CDP is not enabled"
!---   HQ# show ntp status -> synchronizes to 192.168.1.254 after a few minutes (or Fast
!---   Forward Time)
! ==============================================================

! ==============================================================
!--- 10.8.1 Packet Tracer - Configure CDP, LLDP, and NTP
!--- ANSWER SCRIPT FOR ROUTER Branch
!--- Usage: from the console (or CLI tab) on Branch, enter privileged EXEC mode with
!--- "enable", then paste this whole file. Every line beginning with "!" is a comment; IOS
!--- ignores it.
!--- Unlike HQ, Branch's site standardizes on CDP instead of LLDP - simply turning it on is
!--- the entire task here.
! ==============================================================

enable
configure terminal

! --------------------------------------------------------------
!--- CDP is off by default in this scenario - turn it on globally.
! --------------------------------------------------------------
cdp run

end

! ==============================================================
!--- Verification:
!---   Branch# show cdp -> now shows CDP globally enabled
!---   Branch# show cdp neighbors -> BR-SW-1 should appear on G0/0/0
! ==============================================================

! ==============================================================
!--- 10.8.1 Packet Tracer - Configure CDP, LLDP, and NTP
!--- ANSWER SCRIPT FOR SWITCH HQ-SW-1
!--- Usage: from the console (or CLI tab) on HQ-SW-1, enter privileged EXEC mode with
!--- "enable", then paste this whole file. Every line beginning with "!" is a comment; IOS
!--- ignores it.
!--- HQ-SW-1 sends LLDP toward HQ but never receives from it (the mirror image of HQ's own
!--- receive-only configuration), and has LLDP fully disabled on its access port (to the NTP
!--- Server) since that's an end host with nothing useful to discover.
! ==============================================================

enable
configure terminal

! --------------------------------------------------------------
!--- Switch this site's discovery protocol from CDP to LLDP.
! --------------------------------------------------------------
lldp run
no cdp run

! --------------------------------------------------------------
!--- Access port to the NTP Server - no CDP/LLDP neighbor will ever exist here, so
!--- disable LLDP completely (both directions) to avoid leaking any info to that host.
! --------------------------------------------------------------
interface FastEthernet0/24
 no lldp receive
 no lldp transmit
exit

! --------------------------------------------------------------
!--- Uplink to HQ - send LLDP info toward HQ, but don't receive anything back (matches HQ's
!--- own "transmit disabled, receive enabled" configuration on its side of this same link).
! --------------------------------------------------------------
interface GigabitEthernet0/1
 no lldp receive

end

! ==============================================================
!--- Verification:
!---   HQ-SW-1# show lldp neighbors -> nothing appears for HQ (HQ never transmits, and this
!---   switch never receives on G0/1 anyway)
!---   HQ-SW-1# show cdp -> "% CDP is not enabled"
! ==============================================================

! ==============================================================
!--- 10.8.1 Packet Tracer - Configure CDP, LLDP, and NTP
!--- ANSWER SCRIPT FOR SWITCH HQ-SW-2
!--- Usage: from the console (or CLI tab) on HQ-SW-2, enter privileged EXEC mode with
!--- "enable", then paste this whole file. Every line beginning with "!" is a comment; IOS
!--- ignores it.
!--- Same pattern as HQ-SW-1: send-only toward HQ, and LLDP fully disabled on the access
!--- port in use (here, PC1's port instead of a server port).
! ==============================================================

enable
configure terminal

! --------------------------------------------------------------
!--- Switch this site's discovery protocol from CDP to LLDP.
! --------------------------------------------------------------
lldp run
no cdp run

! --------------------------------------------------------------
!--- Access port to PC1 - disable LLDP completely (both directions).
! --------------------------------------------------------------
interface FastEthernet0/1
 no lldp receive
 no lldp transmit
exit

! --------------------------------------------------------------
!--- Uplink to HQ - send only, matching HQ's receive-only side of this link.
! --------------------------------------------------------------
interface GigabitEthernet0/1
 no lldp receive

end

! ==============================================================
!--- Verification:
!---   HQ-SW-2# show lldp neighbors -> nothing appears for HQ
!---   HQ-SW-2# show cdp -> "% CDP is not enabled"
! ==============================================================

! ==============================================================
!--- 10.8.1 Packet Tracer - Configure CDP, LLDP, and NTP
!--- ANSWER SCRIPT FOR SWITCH BR-SW-2
!--- Usage: BR-SW-2 can't be reached by clicking it directly - connect via SSH first
!--- (username admin, password SW2admin#, enable secret SW2EnaAccess#), then enter
!--- privileged EXEC mode and paste this whole file. Every line beginning with "!" is a
!--- comment; IOS ignores it.
!--- BR-SW-1 needs no configuration changes at all in this lab (only used as an SSH
!--- reachability point per the instructions) - only BR-SW-2 and BR-SW-3 get the CDP
!--- restriction below.
! ==============================================================

enable
configure terminal

! --------------------------------------------------------------
!--- Access port to PC2 - stop advertising this switch's own CDP info out toward an end
!--- host that has no use for it.
! --------------------------------------------------------------
interface FastEthernet0/1
 no cdp enable

end

! ==============================================================
!--- Verification:
!---   BR-SW-2# show cdp interface -> FastEthernet0/1 no longer listed as CDP-enabled
!--- CDP itself stays globally enabled here (Branch's site standard) - only this one access
!--- port is restricted.
! ==============================================================

! ==============================================================
!--- 10.8.1 Packet Tracer - Configure CDP, LLDP, and NTP
!--- ANSWER SCRIPT FOR SWITCH BR-SW-3
!--- Usage: BR-SW-3 can't be reached by clicking it directly - connect via SSH first
!--- (username admin, password SW3admin#, enable secret SW3EnaAccess#), then enter
!--- privileged EXEC mode and paste this whole file. Every line beginning with "!" is a
!--- comment; IOS ignores it.
! ==============================================================

enable
configure terminal

! --------------------------------------------------------------
!--- Access port to PC3 - same restriction as BR-SW-2's port to PC2.
! --------------------------------------------------------------
interface FastEthernet0/1
 no cdp enable

end

! ==============================================================
!--- Verification:
!---   BR-SW-3# show cdp interface -> FastEthernet0/1 no longer listed as CDP-enabled
! ==============================================================