PROBLEM: 
Customer is having issues with health check failures. Switches A180E-5 and A180E-6 cannot pass health checks to any other switch. This has been 100% confirmed not a firewall issue.
ICMP healthchecks are passing thru the firewalls, but the Alteon switches are not responding to the healthchecks.

Visio, and TSDUMPs for switches A180E-1 thru 8 have been provided.


SOLUTION:
Incorrect /sys/mnet & mmask setting. MP will not respond to address ranges out side the set value. Therefore, health checks were not being responded to.