Hello AZM
Usually, this happens when there is another routing protocol (or a static route) that provides a route to the destination in question with a smaller Administrative Distance (AD). But since you have already stated that you don’t have any of those, and the fact that the routing table is empty, indicates that the problem is elsewhere.
Now the FD will be infinity if the EIGRP metric is maxed out. Let’s do a calculation.
The EIGRP metric is a 32 bit value, which means it’s maximum value is 4,294,967,295. If you look at the EIGRP equation, taking into account only K1 and K3, you get the following:
Metric = 256 * [(10,000,000/bandwidth)+delay]
where bandwidth is in kilobits and delay is in tens of microseconds.
Looking at your configuration, I wasn’t able to see the speed of the link between the routers, but I did see that we are looking at an Ethernet port (not fast or giga), so I’m assuming 10 Mbps. So:
bandwidth = 10,000 kbps
delay ethernet = 1,677,721 tens of microseconds
delay loopback = 500 tens of microseconds
Plugging this into the equation, we get:
metric = 256 * [(10,000,000/10,000)+(1,677,721+500)] = 429,880,576
This is indeed smaller than the maximum of 4,294,967,295 and should not result in a maximum
However, looking at the FD of the route before you changed the delay, we see a composite metric of 131153920 but I calculate, based on the vector metrics, a metric of 512256. Also, I see a reported metric of 163840 to the loopback destination, whereas it should be 128320.
Again, in your output after the change in delay, I see that the composite metric is greater than the maximum EIGRP metric, although this calculation is not “correct” according to the equation.
The only thing I can think of is to check that the other K values are indeed 0 and that the delay and other parameters of the loopback interface have not been changed in some way. Check the default values of these parameters for the loopback to see if the specific router and IOS combination have some other defaults.
The discrepancy in the calculations must be due to a parameter that has not been included in our calculations of EIGRP. Can you take a look and let us know your findings?
I hope this has been helpful!
Laz