Q47

Consider a network with three routers $\text{P, Q, R}$ shown in the figure below. All the links have cost of unity.

The routers exchange distance vector routing information and have converged on the routing tables, after which the link $\text{Q-R}$ fails. Assume that $\text{P}$ and $\text{Q}$ send out routing updates at random times, each at the same average rate. The probability of a routing loop formation (rounded off to one decimal place) between $\text{P}$ and $\text{Q},$ leading to count-to-infinity problem, is _______________.