I don't think this vim-cmd command queries actual CDP (or LLDP) information provided by your physical switch.
I rather think this info is derived from the old style "observed IP ranges" which you can see on physical NICs in the Configuration-Network Adapters view and elsewhere. It's based on passive sampling of traffic and as such isn't very reliable, especially with many VLANs.
I'm aware this KB article http://kb.vmware.com/kb/1007069 as well as some other articles (http://www.yellow-bricks.com/2011/09/18/cdp-information-using-the-commandline/) imply this is real CDP info, but if it provides me info on uplinks of standard vSwitches which physical switches do not support CDP and exactly the same unreliable stuff as I can see in the observed IP ranges (on dVS uplinks too), then I can't help but assume this is mistaken/a misunderstanding/a bug.
For example, this is the esxcfg-info output of an uplink that is attached to a standard vSwitch and a physical switch that does not support LLDP or CDP.
\==+Physical Nic :
|----Name...............................................vmnic0
[...]
|----Network Hint.......................................11 10.10.9.200/255.255.255.248
[...]
|----Link Up............................................true
|----enabled............................................true
|----CDP Network........................................false
|----LLDP Network.......................................false
# vim-cmd hostsvc/net/query_networkhint --pnic-name=vmnic0
(vim.host.PhysicalNic.NetworkHint) [
(vim.host.PhysicalNic.NetworkHint) {
dynamicType = <unset>,
device = "vmnic0",
subnet = (vim.host.PhysicalNic.NetworkHint.IpNetwork) [
(vim.host.PhysicalNic.NetworkHint.IpNetwork) {
dynamicType = <unset>,
vlanId = 11,
ipSubnet = "10.10.9.200-10.10.9.207",
}
],
connectedSwitchPort = (vim.host.PhysicalNic.CdpInfo) null,
lldpInfo = (vim.host.PhysicalNic.LldpInfo) null,
You only get real CDP/LLDP uplink through distributed vSwitches. This is from an uplink on a dvSwitch that has LLDP enabled:
\==+Physical Nic :
|----Name...............................................vmnic1
[...]
|----Network Hint.......................................71 10.20.10.229/255.255.255.255, 78 10.20.8.0/255.255.255.128, 77 169.254.89.75/255.255.255.255 [...]
|----Link Up............................................true
|----enabled............................................true
|----CDP Network........................................false
|----LLDP Network.......................................true
\==+LLDP Summary :
|----Chassis ID......................................xxxxxxxxxxxxxx
|----Port ID.........................................14005
|----Time-to-live....................................112
|----Timeout.........................................0
|----Samples.........................................2
|----System Name.....................................xxxxxxxxxxxxx