22-5
Catalyst 3550 Multilayer Switch Software Configuration Guide
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Chapter22 Configuring IP Unicast Routing Configuring IP Addressing
Assigning IP Addresses to Network Interfaces
An IP address identifies a location to which IP packets can be sent. Some IP addresses are reserved for
special uses and cannot be used for host, subnet, or network addr esses. Ta ble 22- 2 lists ranges of IP
addresses and shows which are reserved and which are ava ilable for use. RFC 1166, Internet Numbers,
contains the official description of IP addresses.
An interface can have one primary IP address. A mask i dentifies the bit s that de note th e netwo rk number
in an IP address. When you use the mask to subnet a network, the ma sk is referred to as a subnet mask.
To receive an assigned network number, contact your Internet service provi der.
IRDP Disabled.
Defaults when enabled:
Broadcast IRDP advertisements.
Maximum interval between advertisements: 600 seconds.
Minimum interval between advertisements: 0.75 times max interval
Preference: 0.
IP proxy ARP Enabled.
IP routing Disabled.
IP subnet-zero Disabled.
Table22-1 Default Addressing Configuration (continued)
Feature Default Setting
Table22-2 Reserved and Available IP Addresses
Class Address or Range Status
A 0.0.0.0
1.0.0.0 to 126.0.0.0
127.0.0.0
Reserved
Available
Reserved
B 128.0.0.0 to 191.254.0.0
191.255.0.0 Available
Reserved
C 192.0.0.0
192.0.1.0 to 223.255.254
223.255.255.0
Reserved
Available
Reserved
D 224.0.0.0 to 239.255.255.255 Multicast group addresses
E 240.0.0.0 to 255.255.255.254
255.255.255.255 Reserved
Broadcast