3com 5500-ei pwr Instruccion De Instalación

 

1-2 

Table 1-1 IP address classes and ranges 

A 

0.0.0.0 to 127.255.255.255 

Address 0.0.0.0 means this host no this 
network. This address is used by a host at 
bootstrap when it does not know its IP 
address. This address is never a valid 
destination address.  

Addresses starting with 127 are reserved for 
loopback test. Packets destined to these 
addresses are processed locally as input 
packets rather than 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 255.255.255.255 

Reserved for future use except for the 
broadcast address 255.255.255.255.  

 

The following IP addresses are for special use, and they cannot be used as host IP addresses: 

z 

IP address with an all-zeros net ID: Identifies a host on the local network. For example, IP address 

0.0.0.16 indicates the host with a host ID of 16 on the local network. 

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. For example, a packet 

with the destination address of 192.168.1.255 will be broadcasted to all the hosts on the network 

192.168.1.0. 

Subnetting was developed to address the risk of IP address exhaustion resulting from fast expansion of 

the Internet. The idea is to break a network down into smaller networks called subnets by using some 

bits of the host ID to create a subnet ID. To identify 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 net ID and subnet ID whereas 

the part containing consecutive zeros identifies the host ID. 

 shows how a Class B network is subnetted. 

Figure 1-2 Subnet a Class B network