Without CIDR,a Network First Second Third Fourth router must Number Octet Octet Octet Octet maintain 172.24.0.0/16 10101100 00011000 00000000 00000000 individual 172.25.0.0/16 10101100 00011001 00000000 00000000 routing table 172.26.0.0/16 10101100 00011010 00000000 00000000 entries for these 172.27.0.0/16 10101100 00011011 00000000 00000000 class B networks. 172.28.0.0/16 10101100 00011100 00000000 00000000 172.29.0.0/16 10101100 00011101 00000000 00000000 172.30.0.0/16 10101100 00011110 00000000 00000000 With CIDR,a 172.31.0.0/16 10101100 00011111 00000000 00000000 router can Network First Second Third Fourth summarize Number Octet Octet Octet Octet these routes 172.24.0.0/16 10101100 00011000 00000000 00000000 using a single 172.25.0.0/16 10101100 00011001 00000000 00000000 network 172.26.0.0/16 10101100 00011010 00000000 00000000 address by 172.27.0.0/16 10101100 00011011 00000000 00000000 using a 13-bit 172.28.0.0/16 10101100 00011100 00000000 00000000 prefix: 172.29.0.0/16 10101100 00011101 00000000 00000000 172.24.0.0/13 172.30.0.0/16 10101100 00011110 00000000 00000000 172.31.0.0/16 10101100 00011111 00000000 00000000 eps: 入 1.Count the number of left-most matching bits,/13 2.Add all zeros after the last matching bit: 172.24.0.0=10101100000110000000000000000000Without CIDR, a 信息网络与协议 router must maintain individual routing table entries for these class B networks. With CIDR, a router can summarize these routes using a single network address by using a 13-bit prefix: 172.24.0.0 /13 1. Count the number of left-most matching bits, /13 2. Add all zeros after the last matching bit: 172.24.0.0 = 10101100 00011000 00000000 00000000 Steps: