ARP is fine and traffic through the DUT is okay between 2 STCv ports.
When a routing protocol such as OSPF or ISIS is setup, both STC and DUT doesn’t see the control messages even though both sides show it is sending it.
Make sure you are not using any link local MAC addresses.
Those can get filtered out by the bridge.
Any source address 01:XX:XX:XX:XX:XX is invalid
Slow protocol frames 01:80:C2:00:00:0X,
Link local frames 01:00:00:00:00:01 and LinkOAM frames get dropped.
02:XX:XX:XX:XX:XX is locally administered and goes 1 hop.
VMWare Possible solution:
Set the Promiscuous mode in two places.
1. vSphere Client in VMWare
2. VM console on the virtual port
Notify your VMWare administrator if you don’t have access to it.
Login/Password to the Spirent VM console is admin/spt_admin
Command to change Promiscuous mode is promisc on
Note: Setting the vSwitch to promiscuous mode to support multiple devices per port using the standard vSwtich has significant negative effects on system performance and should be avoided if possible.
If a Cisco Nexus 1000v vSwitch is used in conjunction with vSphere, neither setting the vSwitch to promiscuous mode or using the "Use Source MAC address from Physical Interface" feature in the STC GUI is required. Multiple devices with random MAC Addresses is supported in this configuration without performance impacts. The Nexus 1000v vSwitch is a learning switch, and behaves like any standard hardware based switch.