Port Mapping - Dell FX2s Chassis with Cisco Nexus\FEX Switches

Question

having some trouble with doing remote port mapping with dell FX2s chassis and fc430 blades\sleds. the goal is to figure out what are the ports in nexus switches\cisco fex that the dell chassis 10Gb sfp+ is connected to.

as someone is familiar with this chassis, it got 2 Dell PowerEdge FN 410S IOM modules, in our configuration, each connected with 2 cables to our cisco nexus backbones through a Cisco FEX.

when wanting to find the port mapping for a regular rack server (let's say HPE DL360) with an esxi installed on, i'm just shutting down one of the ports with "esxcli network nic down -n vmnicX" command as see the port flap in switch with the "terminal monitor" command in each backbone switch.

with this chassis, even due shutting down all the ports in one of I/O modules each time, the terminal monitor command doesn't show the flapping for some reason I cannot figure.

the only option I can think of, is driving to datacenter and port mapping the cables like a monkey, but I want to save these procedure, as I need to do it for multiple dell FX2s Chassis.

an idea will be appreciated.

Answer 1

(Legally required notice - I work for Dell)

If I understand your question correctly, you're asking how the ports of the FN410 map to the sleds.

The last four ports, tengigethernet 0/9-12 of the FN410 are forward facing (out to your Nexus). The first 8 use the internal chassis network (it's just copper runs on the board) and run to the sleds. It depends on what sleds you have with what NICs as to exactly where they go. You can check LLDP neighbors or look at the ARP table to see exactly. You don't need to shut anything down to check. If the switches aren't IP'd you can still get still get to them via the CMC:

1. SSH to the CMC's IP address. Use the CMC username/password to log in.
2. Run the command connect -m switch-1 (or switch-2) to connect to the switch.
3. If the switch is in BMP mode. Hit A to cancel it.
4. <do stuff> ex: show lldp neighbors or show arp

Be aware that the switch has multiple modes. It was designed for server people who know nothing about networking so by default most of the functionality is restricted and you're meant to use the GUI like a good server admin. This was one of the reasons that box was so popular but if you try to fight the man (the switch) and make it do things you wouldn't let your server admin do you'll leave confused and frustrated. If you want to disable the GUI and make the FN410 behave like a fully managed switch you have to put it in full switch mode (stack-unit 0 iom-mode full-switch). This isn't necessary for just checking the LLDP neighbors but it will be if you want to config it like you would a regular switch.

If you have two sleds each with 4 port NICs and the rest is storage I think switch 1 goes to ports 1 and 3 on the sleds and switch 2 goes to 2 and 4. I'd just check it to be sure anyway.