We have 2 * 3560 switches only configured for L2 (etherchannel between them) there are 2 * 3800 (12.4) routers configured with HSRP each router is connected to a different 3560 switch. There is a problem that is sporadic where it is not possible to ping the VIP, when looking at the problem it is not possible to ping the other router from either the switch or 1st router. The logs show nothing on either the switch or routers, the only thing that is wrong is an incomplete Mac address entry. If the Router is restarted service returns. The link between the routers is direct (no switch connection)
There is an added complication in that the routers are managed externally and the LAN internally. Any suggestions as to how to track this problem down as currently neither party can see anything glaringly obvious.