Knowledge Base
Cisco Discovery Protocol (CDP) network information via command line and VirtualCenter on an ESX host
Purpose
This article describes configuring and viewing Cisco Discovery Protocol (CDP) on ESX 3.x .
Resolution
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Utilizing Cisco Discovery protocol (CDP) to get switch port configuration information.
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This command is utilized to troubleshoot network connectivity issues related to VLAN tagging methods on virtual and physical port settings.
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In order to establish compatible virtual switch configuration
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See the following article "VLAN Configuration on Virtual Switch, Physical Switch, and Virtual Machines - ESX 3.X"(1003806)
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Before extracting CDP information confirm that CDP is enabled on ESX virtual switch and physical switch.
Extracting CDP information via the ESX command line
To extract CDP information using the ESX command line:
- Log in into ESX 3.5 via SSH as root.
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Run the following command on ESX command line :
> vmware-vim-cmd hostsvc/net/query_networkhint
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The following information is displayed:
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Virtual switch port information
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CDP information from the physical Cisco switch connecting to the ESX host .
The following is an example output of the CDP command:
(vim.host.PhysicalNic.NetworkHint) [
(vim.host.PhysicalNic.NetworkHint) {
dynamicType = <unset>,
device = "vmnic3",
subnet = (vim.host.PhysicalNic.NetworkHint.IpNetwork) [
(vim.host.PhysicalNic.NetworkHint.IpNetwork) {
dynamicType = <unset>,
vlanId = 0,
ipSubnet = "10.21.4.1-10.21.7.254",
}
],
connectedSwitchPort = (vim.host.PhysicalNic.CdpInfo) null,
},
(vim.host.PhysicalNic.NetworkHint) {
dynamicType = <unset>,
device = "vmnic1",
subnet = (vim.host.PhysicalNic.NetworkHint.IpNetwork) [
(vim.host.PhysicalNic.NetworkHint.IpNetwork) {
dynamicType = <unset>,
vlanId = 0,
ipSubnet = "10.21.3.1-10.21.3.15",
}
],
connectedSwitchPort = (vim.host.PhysicalNic.CdpInfo) {
dynamicType = <unset>,
cdpVersion = 0,
timeout = 0,
ttl = 169,
samples = 2982,
devId = "PA-3210-2-R15-SW1",
address = "10.21.10.115",
portId = "GigabitEthernet1/0/7", <<<<<<<Switch Port ID>>>>>>
deviceCapability = (vim.host.PhysicalNic.CdpDeviceCapability) {
dynamicType = <unset>,
router = false,
transparentBridge = false,
sourceRouteBridge = false,
networkSwitch = true,
host = false,
igmpEnabled = true,
repeater = false,
},
softwareVersion = "Cisco IOS Software, C3750 Softw",
hardwarePlatform = "cisco WS-C3750G-48TS",
ipPrefix = "0.0.0.0",
ipPrefixLen = 0,
vlan = 3, <<<<<<<VLAN ID>>>>>>>>>>>>
fullDuplex = true,
mtu = 0,
systemName = "",
systemOID = "",
mgmtAddr = "10.21.10.115",
location = "",
},
},
Extracting CDP information via VirtualCenter
To extract CDP information using VirtualCenter:
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Log in in to Virtual Center
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Select Host > Configuration > Networking > Select Tool Tip (the balloon icon) under vSwitch Properties .
The following screen shot highlights where to click to view CDP information:
Selecting the above tool tip will open CDP infromnation pop-up.
The following screen shot illustrates the CDP window.
Additional Information
Extracting network Information via Cisco Discovery Protocol (CDP)
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Enable CDP via commnad line for vSwitch. For more Information see Configuring the Cisco Discovery Protocol (CDP) with ESX Server (1003885)
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Enbale CDP Cisco switch level. For more Information see Configuring the Cisco Discovery Protocol (CDP) with ESX Server (1003885)
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