lahell / PSDiscoveryProtocol

PSDiscoveryProtocol

Capture and parse CDP and LLDP packets on local or remote computers

CDP and LLDP

PSDiscoveryProtocol does not return all information available in CDP and LLDP packets. If you want to know what information is available use Export-Pcap and open the pcap file in Wireshark or another tool with a more complete implementation.

Some vendors only send mandatory TLVs in which case this module will only return Port from captured LLDP packets.

Installation

Install-Module -Name PSDiscoveryProtocol

Usage

On this page you will find a few examples of how to use this module.

For more examples please read help:

Get-Help -Name Invoke-DiscoveryProtocolCapture -Full
Get-Help -Name Get-DiscoveryProtocolData -Full
Get-Help -Name Export-Pcap -Full

Capture and parse LLDP on local computer

$Packet = Invoke-DiscoveryProtocolCapture -Type LLDP
Get-DiscoveryProtocolData -Packet $Packet

Output

Model       : WS-C2960-48TT-L
Description : HR Workstation
VLAN        : 10
Port        : Fa0/1
Device      : SWITCH1.domain.example
IPAddress   : 192.0.2.10
Computer    : COMPUTER1.domain.example
Type        : LLDP

Capture and parse CDP on remote computers

'COMPUTER1', 'COMPUTER2' | Invoke-DiscoveryProtocolCapture -Type CDP | Get-DiscoveryProtocolData

Output

Port      : FastEthernet0/1
Device    : SWITCH1.domain.example
Model     : cisco WS-C2960-48TT-L
IPAddress : 192.0.2.10
VLAN      : 10
Computer  : COMPUTER1.domain.example
Type      : CDP

Port      : FastEthernet0/2
Device    : SWITCH1.domain.example
Model     : cisco WS-C2960-48TT-L
IPAddress : 192.0.2.10
VLAN      : 20
Computer  : COMPUTER2.domain.example
Type      : CDP

Capture on remote computers and export to pcap

'COMPUTER1', 'COMPUTER2' | Invoke-DiscoveryProtocolCapture | Export-Pcap -Path packets.pcap

Speed up capturing in PowerShell 7

By leveraging the new -Parallel parameter on ForEach-Object we can capture simultaneously on multiple computers.

#Requires -Version 7
'COMPUTER1', 'COMPUTER2', 'COMPUTER3' | ForEach-Object -Parallel {
    Invoke-DiscoveryProtocolCapture -ComputerName $_ | Get-DiscoveryProtocolData
}