CLI Reference Guide-R04

Chapter 31 | IP Interface Commands
IPv4 Interface
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Command Usage
◆ If this router is directly connected to end node devices (or connected to end
nodes via shared media) that will be assigned to a specific subnet, then you
must create a router interface for each VLAN that will support routing. The
router interface consists of an IP address and subnet mask. This interface
address defines both the network number to which the router interface is
attached and the router’s host number on that network. In other words, a
router interface address defines the network and subnetwork numbers of the
segment that is connected to that interface, and allows you to send IP packets
to or from the router.
◆ Before any network interfaces are configured on the router, first create a VLAN
for each unique user group, or for each network application and its associated
users. Then assign the ports associated with each of these VLANs.
◆ An IP address must be assigned to this device to gain management access over
the network or to connect the switch to existing IP subnets. A specific IP
address can be manually configured, or the switch can be directed to obtain an
address from a BOOTP or DHCP server. Valid IP addresses consist of four
numbers, 0 to 255, separated by periods. Anything other than this format will
not be accepted by the configuration program.
◆ An interface can have only one primary IP address, but can have many
secondary IP addresses. In other words, secondary addresses need to be
specified if more than one IP subnet can be accessed through this interface.
Note that a secondary address cannot be configured prior to setting the
primary IP address, and the primary address cannot be removed if a secondary
address is still present. Also, if any router/switch in a network segment uses a
secondary address, all other routers/switches in that segment must also use a
secondary address from the same network or subnet address space.
◆ If bootp or dhcp options are selected, the system will immediately start
broadcasting service requests for all VLANs configured to obtain address
assignments through BOOTP or DHCP. IP is enabled but will not function until a
BOOTP or DHCP reply has been received. Requests are broadcast periodically
by the router in an effort to learn its IP address. (BOOTP and DHCP values can
include the IP address, default gateway, and subnet mask). If the DHCP/BOOTP
server is slow to respond, you may need to use the ip dhcp restart client
command to re-start broadcasting service requests, or reboot the switch.
Note: Each VLAN can be assigned its own IP interface address. You can manage the
switch via any of these IP addresses.