We have deployed an HSRP pair of CSR1000v routers on clustered ESXi servers utilizing the VMware 5.5 distributed switch. The routers are used to switch our privately addressed hosts in different networks/vlans on the distributed switch in an infrastructure service provider "cloud" environment.
In our development we've found that we are getting DUP ping responses (3 DUP responses to be exact) from Linux hosts that ping other Linux hosts on the same network when either one of the Linux hosts is on the same clustered ESXi server as our active CSR.
Some observations:
1. The DUP responses do not happen for Windows hosts under the same circumstances.
2. The DUP responses from the Linux hosts go away when the HSRP configuration is removed from the routers.
3. Linux, Windows, and the CSRs are all using the same virtual host adapter type (vmxnet3).
4. The CSR interfaces are setup with basic HSRP, no ip redirects, and no proxy-arp set.
5. The vlans on the VMware distributed switch security setting are set to "Accept" for promiscuous mode and forged transmits (the only way HSRP seems to work).
Has anyone seen this type of problem or have any suggestions on how to resolve/troubleshoot it?
Thanks,
Mike
