CDP and LLDP

[bfrakes]

I have recently upgraded ISCSI switches to Dell 7000 series switches.  To my surprise vCenter started seeing the network information via CDP.  The only problem is these switches only run LLDP.  My Dell 5000 series switches also have LLDP but vCenter will not see them.  I know that if I use Distributed Virtual Switch LLDP is enabled, but I am running Standard Virtual switches.

I've tried duplicating the settings from the 7000 series switches on the 5000 series switches, but nothing so far has worked.

Has anyone made LLDP work on 5000 series Dell switches in vCenter?

I am trying to create a totally accurate map of the network and CDP/LLDP is the only way I have found that reflects where the real cards on the host ESX servers are connected.  ESX seems to mask the Mac address so I cannot query the switches to find the Mac address of the virtual nic.  Bizarre behavior...

Please advise...

[vmroyale]

Note: Discussion successfully moved from VMware ESXi 5 to VMware vSphere™ vNetwork

[chriswahl]

Have you isolated what device is providing CDP information? Even if your Dell switches use LLDP, they can still pass along CDP data.

If you're looking for Dell product support of a specific protocol, you might try their forums or engage with someone like Dennis Smith to see if there is an updated package / image.

[bfrakes]

Yes our new dell pct7048 switches seem to have no problem passing CDP data up to vCenter.  I was amazed that they did it. I had Cisco switch before but after a lightning strike zapped two of them I decided that I could not trust the other three.  They were 5 years old and needed to be replaced.

I will contact Dell to see if the can figure it out.

[sfolsson]

There is a way to get ESXi 5.5 to advertise LLDP information for a standard virtual switch, however it is undocumented and almost certainly unsupported by VMware. Basically, use vsish to set the value of lldp/enable to '1' for each uplink port, (/net/portset/<vSwitch_name>/ports/<uplink_port_id>/lldp/enable).

I've seen it work on a Dell Force10 and Cisco SG-300 and although I would expect it to work with a Dell PowerConnect 5000 series switch too, I haven't tested it (it's just LLDP after all).

In my limited experimentation, LLDP can also be enabled on an ESXi 5.1 vSwitch uplink port but it won't advertise to the switch by default. I've posted some notes to http://blog.shanonolsson.com/blog/2014/01/03/lldp-and-standard-virtual-switches/ - hopefully this is of some assistance.

Another note on CDP support: The vSphere Networking documentation indicates that CDP is only available when connected to "Cisco physical switches". I've read that a few non-Cisco switches can handle CDP information through something called "Industry Standard Discovey Protocol" (ISDP).

[bfrakes]

The pktcap-uw did show me the ports the vmnic's were connected to but it did not show which switch stack they were connected to accurately. 

I have three switch stacks:

6 Dell 48 port stacked with HDMI cables in my trust network

2 Dell 48 port stacked with HDMI cables in my vmotion network

2 Dell 7000 series 48 port stacked switches in my ISCSI network.

Not sure why it did not show the switch stack names correctly.

[sfolsson]

I'm not really sure what inaccuracy you're seeing... does it match the System Name shown when executing for example show system unit <n>? Also, are you seeing port IDs in the form <unit number>/<slot number>/<port number>?

You may also be seeing the Chassis ID of the stack member: System Name is an optional TLV and it may be necessary to enable SN TLVs in the switches' LLDP configurations.

Potentially, there may also be some discrepancy if you're using link aggregation groups / LACP.

I'd normally familiarise myself with specific product documentation and perform a reasonable amount of testing if undertaking a similar activity, regardless of the method. In a test environment I'd probably spend a little time exploring how LLDP can be configured and LLDP information can be retrieved via SNMP (for the switch). If I were attempting to gather topology information and create a network map, I'd probably also be looking for information other than available by LLDP.

I hope you're able to extract the information you need - even if LLDP only covers part of the requirement.