The debug output indicates that detailed IP packet tracking is enabled for ACL100. The log entries show packets with source IP s=1.1.1.1 (associated with Serial1/0) and destination IP d=10.1.1.1 (associated with Serial3/0). The packets are of the ICMP type, as shown by "ICMP type=0, code=0". This confirms that ACL100 is indeed tracking ICMP traffic from Serial 1/0 to Serial3/0.