While setting up VMWare networking you might encounter a problem where only one Virtual Machine has access to the network.
I wasted a lot of time figuring this issue out, hopefully this will help someone.
I tried every possible configuration of VMware networking / vSwitches / Load Balancing etc.
After all that failed I installed a packet sniffer on the virtual machine that had no connectivity.
Here you can see the broadcast packets are being sent out, however, they get no reply.
I also noticed that I’m picking up the broadcasts from other hosts, meaning we are connected to the physical network.
I remembered that in Cali we had the same problem with Cisco switch, blocking multiple MAC id’s on the same port.
This behavior is by design, a “Port Security” feature that Cisco decided to turn on by default on some of its switches.
Here’s the explanation from Cisco website.
You can use the port security feature to restrict input to an interface by limiting and identifying MAC addresses of the workstations that are allowed to access the port. When you assign secure MAC addresses to a secure port, the port does not forward packets with source addresses outside the group of defined addresses. If you limit the number of secure MAC addresses to one and assign a single secure MAC address, the workstation attached to that port is assured the full bandwidth of the port. If a port is configured as a secure port and the maximum number of secure MAC addresses is reached, when the MAC address of a workstation attempting to access the port is different from any of the identified secure MAC addresses, a security violation occurs. If a workstation with a secure MAC that is address configured or learned on one secure port attempts to access another secure port, a violation is flagged.
To resolve the issue we need to identify the physical switch port that the NIC is sitting on. Cisco Discovery Protocol (CDP) needs to be ON. This will allow VMWare to identify which switch ports correspond to server NICs.
Login to the switch.
On the dashboard, select SmartPorts Wizard
Select the port in question by clicking on it.
Select Switch from drop down, Next, Next on the next window.
Done. This disables Port Security.