Operation Manual –IP Address-IP PerformanceH3C S3100 Series Ethernet Switches Chapter 1 IP Addressing Configuration1-2Table 1-1 IP address classes and rangesClass Address range DescriptionA 0.0.0.0 to 127.255.255.255Address 0.0.0.0 means this hostno this network. This address isused by a host at bootstrapwhen it does not know its IPaddress. This address is nevera valid destination address.Addresses starting with 127 arereserved for loopback test.Packets destined to theseaddresses are processedlocally as input packets ratherthan sent to the link.B 128.0.0.0 to 191.255.255.255 ––C 192.0.0.0 to 223.255.255.255 ––D 224.0.0.0 to 239.255.255.255 Multicast address.E 240.0.0.0 to 255.255.255.255Reserved for future use exceptfor the broadcast address255.255.255.255.1.1.2 Special Case IP AddressesThe following IP addresses are for special use, and they cannot be used as host IPaddresses:z IP address with an all-zeros net ID: Identifies a host on the local network. Forexample, IP address 0.0.0.16 indicates the host with a host ID of 16 on the localnetwork.z IP address with an all-zeros host ID: Identifies a network.z IP address with an all-ones host ID: Identifies a directed broadcast address. Forexample, a packet with the destination address of 192.168.1.255 will bebroadcasted to all the hosts on the network 192.168.1.0.1.1.3 Subnetting and MaskingSubnetting was developed to address the risk of IP address exhaustion resulting fromfast expansion of the Internet. The idea is to break a network down into smallernetworks called subnets by using some bits of the host ID to create a subnet ID. Toidentify the boundary between the host ID and the combination of net ID and subnet ID,masking is used.Each subnet mask comprises 32 bits related to the corresponding bits in an IP address.In a subnet mask, the part containing consecutive ones identifies the combination of netID and subnet ID whereas the part containing consecutive zeros identifies the host ID.
