Sunday, May 4, 2008

How to Enable CDP On ESX3.X Host

VMWare has made CDP (Cisco Discovery Protocol ) available to their host. What does it mean to you as a ESX administrator and how does it help Networking folks ?

When you the CDP is running on router/switch where the physical network card is connected it provide information to both Network administrator and ESX admin about host name/network card. This information help when you are trying to figure out which network card on the host is connected to which physical switch.

We have installed VC2.5 (as you can find in my earlier blog) an migrated the host from Virtual Center2.0 to Virtual Center 2.5. To my surprise I could not find CDP feature turned on


Here came my GURU  and ask me to run

esxcfg-vswitch -B both <switch name> and BINGO see what I got


When CDP database is checked at switch level this is how it looks like

<Switch Name>#sh cdp nei

Capability Codes: R - Router, T - Trans Bridge, B - Source Route Bridge

S - Switch, H - Host, I - IGMP, r - Repeater, P - Phone

Device ID Local Intrfce Holdtme Capability Platform Port ID

<Switch Name1> Gig 0/20 131 R S I WS-C6509 Gig 7/40

<Switch Name2> Gig 0/24 147 R S I WS-C6509 Gig 7/40

<Host Name > Gig 0/1 130 S VMware ESXvmnic5

<Switch Name>#sh cdp nei g0/1 detail


Device ID: <Host_Name>

Entry address(es):

IP address:

Platform: VMware ESX Server, Capabilities: Switch

Interface: GigabitEthernet0/1, Port ID (outgoing port): vmnic5

Holdtime : 161 sec

Version :


1 comment:

Anonymous said...

Thx ! it also works on esxi 4.1

/ RkM