Hello Istvan,
Use a high delay setting on the FastEthernet0/0 interface on R1. Because EIGRP takes, by default, bandwidth and delay components into account when computing the composite metric, increasing the delay will make the metric higher and thus less preferred. For example, set the delay to 1000000 (one million):
interface FastEthernet0/0
delay 1000000
After changing the delay, wait approximately 10 seconds for EIGRP to reflect on the changed delay.
Do not change the bandwidth setting to influence EIGRP metrics. The bandwidth command should always express the realistic bandwidth of the interface.
Best regards,
Peter
