R1#sh run int e0/0 Building configuration... Current configuration : 130 bytes ! interface Ethernet0/0 ip address 17.57.100.1 255.255.255.0 ip pim sparse-dense-mode ip igmp access-group 1 half-duplex end R1#sh run | i access-list access-list 1 deny 224.20.73.1 15.128.20.0 access-list 1 permit any R1#