Pseudo hop count

The number of hops that the primary server adds to the true hop count (the number of internal and external bridges and routers between a client and the server) when it advertises the route to the SFT III MSEngine.

If SFT III servers reside on different network segments, the hop count for one server is higher than the other. To ensure that packets are rerouted properly to the surviving server in the event one server fails, the primary server advertises an artificially high hop count---the true hop count plus a pseudo hop count, as shown in the following figure:

Figure 62
Pseudo Hop Count

SFT III uses the pseudo hop count to accelerate routing changes when a server switchover occurs in mirrored servers on different network segments.

NOTE:  If the SFT III servers are installed on the same network segment, there are no routers and SFT III does not use the pseudo hop count.

If the primary server fails, the surviving server advertises the true hop count. Routers immediately see the surviving server as the best route to the MSEngine.

The total hop count (the true hop count plus the pseudo hop count) between a client and the server cannot exceed 16.

SET parameters enable the pseudo hop count and determine its maximum value.