O'Reilly logo
  • Hirofumi Takahashi thinks this is interesting:

Recall the discussion of DUAL earlier in this chapter. When an entry in a router’s EIGRP topology table changes for the worse (either the metric increases, or the successor is no longer accessible), if there is no feasible successor for the address, the entry goes into Active state, and the router sends query packets to all its neighbors. If Earhart’s link to Yeager, in Figure 7-36, goes down, Earhart sends queries to all its neighbors, including Johnson and Lindbergh, to find out if any neighbors have a path to Yeager. Earhart cannot modify its active entries in the topology table unt...