Easy LanMap Creation

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QUESTION :

I am a student and I want to take the LanMap of the entire Building. There are at least 10 switch boxes with 2 in each floor on a 5 storied building. Each Switch Box contains 2 Switches with 24/48 ports. At least 4 racks are used with the switches for assorting the cables. There are Lan Ports setup at various classrooms connected to the rack and then to the switches.

Right now, I am using a LanTester. I connect one LanTester to the LanPort in the class and one to the Rack. When the 2 light turns ON on the device I map the corresponding wiring. Due to the lack of any reference on the Wiring, the task is seeming very hectic. Wiring is all masked to the wall. Some of the LAN Ports are system connected and some are not.

I am really new at this, as you would know by now. Is there any better way of doing it?

ANSWER :

I will assume the switches are managed switches running LLDP. You should be able to install OpenLLDP to your laptop to query the switch you’re attached to. (A well-managed network will block LLDP transmission to edge ports, but I trust you’re working with the network administrator and can get around that problem.)

I’m on a Mac so I downloaded and built the software from source. Now I can run sudo /usr/local/sbin/lldpd -i en0 to collect information from my Ethernet port. After a few seconds /usr/local/bin/lldpneighbors will show me what I’m connected to. Packets are only sent every 30 seconds so sometimes there’s a wait. Here’s sample output:

Interface 'en0' has 1 LLDP Neighbors: 

Neighbor 1:
    Chassis ID:             MAC Address - 08 2e 5f 12 34 56 
    Port ID:                Locally Assigned - 3
    Time To Live:           120 seconds
    Port Description:       3
    System Name:            Victoria_Switch
    System Description:     ProCurve J9137A Switch 2520-8-PoE, revision S.14.30, ROM S.14.03
    System Capabiltiies:    Bridge/Switch (enabled)
    Management Address:     IPv4 - 192.168.000.000 (ifIndex - 0) (OID: Standard LLDP MIB)
    End Of LLDPDU:  

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