R1#sh run | b router
router eigrp 100
 network 17.57.100.1 0.0.0.0
 network 208.28.1.1 0.0.0.0
 neighbor 208.28.1.3 Serial0/0.1   <---------to peer with R2 (ignoring the task)
 neighbor 208.28.1.2 Serial0/0.1
 no auto-summary



R2#sh run | b router eigrp
router eigrp 100
 network 208.28.1.3 0.0.0.0
 neighbor 208.28.1.1 Serial1/0.1   <---------to peer with R1 (ignoring the task)
 neighbor 208.28.1.2 Serial1/0.1
 no auto-summary
!

R3#sh run | b router
router eigrp 100
 network 17.80.1.1 0.0.0.0
 network 208.28.1.2 0.0.0.0
 neighbor 208.28.1.3 Serial1/0
 neighbor 208.28.1.1 Serial1/0
 no auto-summary
!