Multi-vendor Network

Interactive Network Topology See this Topology Diagram in Interactive Mode.

Objective

To design and validate a multi-vendor network discovery environment where both Cisco Discovery Protocol (CDP) and Link Layer Discovery Protocol (LLDP) coexist without interference.
The goal is to segregate Cisco-to-Cisco communication zones from multi-vendor interoperability zones — ensuring that each protocol operates only where it’s most effective.

Scenario Overview

In a mixed enterprise environment, not all devices support CDP.
Routers and switches that connect to Cisco equipment use CDP for detailed neighbor discovery, while ports facing third-party or open-standard devices use LLDP.
This selective configuration demonstrates protocol separation, control, and vendor interoperability testing.

Implementation Summary

Device	Cisco Zones (CDP)	Multi-Vendor Zones (LLDP)	Protocol Behavior	Notes / Purpose
Router1	e0/1, e0/2	e0/0, e0/3	CDP enabled on Cisco zones; LLDP transmit-only on multi-vendor links	Prevents overlap, shares link info with non-Cisco devices
Router2	e0/0, e0/2	e0/1, e0/3	CDP and LLDP separated by interface	Clean protocol boundaries, avoids duplicate discovery
Router3	----	All Ethernet ports (LLDP active)	LLDP transmit-only on e0/2; CDP active only on select Cisco links	Ensures full LLDP visibility, keeps backward Cisco compatibility
Switch1	e0/0, e0/1	e0/2 (receive-only)	CDP for Cisco links; LLDP limited to receiving on multi-vendor port	Acts as bridge between Cisco and multi-vendor zones
Switch2	—	e0/0–e0/3 (except e0/3 receive-only)	LLDP transmit/receive on all, CDP disabled	Pure LLDP environment for interoperability testing

Result

This topology cleanly divides discovery domains:

CDP zones: internal Cisco-to-Cisco connectivity
LLDP zones: external or third-party interoperability points

The result is a hybrid, controlled discovery environment that demonstrates professional-grade network segmentation and multi-vendor awareness — a critical skill in modern enterprise networks where Cisco gear coexists with other vendors.

Topology DIAGRAM

Command On Each Device

Router1

Goal:
CDP on e0/1 & e0/2 (Cisco zone)
LLDP on e0/0 (Tx/Rx) and e0/3 (Tx only)

conf t
! --- Enable CDP globally
cdp run
! --- Enable LLDP globally
lldp run

! --- CDP-enabled interfaces
int e0/1
 cdp enable
 no lldp transmit
 no lldp receive
exit

int e0/2
 cdp enable
 no lldp transmit
 no lldp receive
exit

! --- Unused Port
int e0/0
 no cdp enable
 no lldp transmit
 no lldp receive
exit
! --- LLDP-enabled interface
int e0/3
 no cdp enable
 lldp transmit
 no lldp receive
exit

Router2

Goal:
CDP on e0/0 & e0/2
LLDP on e0/1 & e0/3

conf t
cdp run
lldp run

! --- CDP zone
int e0/0
 cdp enable
 no lldp transmit
 no lldp receive
exit

int e0/2
 cdp enable
 no lldp transmit
 no lldp receive
exit

! --- LLDP zone
int e0/1
 no cdp enable
 lldp transmit
 lldp receive
exit

int e0/3
 no cdp enable
 lldp transmit
 lldp receive
exit

Router3

Goal:
CDP disabled Globally LLDP on all Ethernet ports (Tx/Rx), except e0/2 Tx only

conf t
no cdp run
lldp run

! --- LLDP on all Ethernet
int e0/0
 lldp transmit
 lldp receive
exit
! --- UNused Port
int e0/1
 no lldp transmit
 no lldp receive
exit

int e0/2
 lldp transmit
 no lldp receive
exit

int e0/3
 lldp transmit
 lldp receive
exit

! --- CDP kept for Serial interfaces in CML entering Serial interface of this device is not permit
int range s1/0 - 1/3
 no lldp transmit
 no lldp receive
exit

end
wr

Switch1

Goal:
CDP on e0/0 & e0/1
LLDP receive-only on e0/2

conf t
cdp run
lldp run

! --- Cisco zone (CDP)
int e0/0
 cdp enable
 no lldp transmit
 no lldp receive
exit

int e0/1
 cdp enable
 no lldp transmit
 no lldp receive
exit

! --- Multi-vendor receive-only LLDP
int e0/2
 no cdp enable
 no lldp transmit
 lldp receive
exit

! --- Disable LLDP entirely on e0/3
int e0/3
 no cdp enable
 no lldp transmit
 no lldp receive
exit

end
wr

Switch2

Goal:
CDP disabled Globally
LLDP on all interfaces (Tx/Rx), except e0/3 Rx-only

conf t
no cdp run
lldp run

! --- LLDP full Tx/Rx
int range e0/0 - 2
 no cdp enable
 lldp transmit
 lldp receive
exit

! --- LLDP Rx-only
int e0/3
 no cdp enable
 no lldp transmit
 lldp receive
exit

end

Summary Table

Device	CDP Interfaces	LLDP Interfaces (Tx/Rx)	Special Cases
Router1	e0/1, e0/2	e0/0 (Tx/Rx), e0/3 (Tx only)	–
Router2	e0/0, e0/2	e0/1, e0/3	–
Router3	e0/1 + Serial ports	e0/0, e0/1, e0/3	e0/2 Tx only
Switch1	e0/0, e0/1	e0/2 Rx only	–
Switch2	None	e0/0–e0/2 (Tx/Rx)	e0/3 Rx only

Download YAML File For CMLFile