59-15
Catalyst 4500 Series Switch, Cisco IOS Software Configuration Guide - Cisco IOS XE 3.9.xE and IOS 15.2(5)Ex
Chapter 59 Configuring the Cisco IOS DHCP Server
Configuring DHCP Address Pools
Troubleshooting Tips
If you are using secondary IP addresses under a single loopback interface and using secondary subnets
under a DHCP pool, use one DHCP pool to configure networks for all the secondary subnets instead of
using one pool per secondary subnet. The
network
network-number
[
mask
|
/
prefix-length
] [
secondary
]
command must be configured under a single DHCP address pool rather than multiple DHCP address
pools.
The following is the correct configuration:
ip dhcp pool dhcp_1
network 172.16.1.0 255.255.255.0
network 172.16.2.0 255.255.255.0 secondary
network 172.16.3.0 255.255.255.0 secondary
network 172.16.4.0 255.255.255.0 secondary
!
interface Loopback111
ip address 172.16.1.1 255.255.255.255 secondary
Step 16
Switch(dhcp-config)#
network
network-number
[
mask
|
/
prefix-length
]
[
secondary
]
(Optional) Specifies the network number and mask of a secondary
DHCP server address pool.
•
Any number of secondary subnets can be added to a DHCP
server address pool.
•
During execution of this command, the configuration mode
changes to DHCP pool secondary subnet configuration mode,
which is identified by (config-dhcp-subnet-secondary)#
prompt. In this mode, the administrator can configure a
default device list that is specific to the subnet.
•
See Troubleshooting Tips section if you are using secondary
IP addresses under a loopback interface with DHCP
secondary subnets.
Step 17
Switch(config-dhcp-subnet-secondary)#
override
default-router
address
[
address2
...
address8
]
(Optional) Specifies the default device list that is used when an IP
address is assigned to a DHCP client from a particular secondary
subnet.
•
If the subnet-specific override value is configured, this
override value is used when assigning an IP address from the
subnet; the network-wide default device list is used only to
set the gateway device for the primary subnet.
•
If this subnet-specific override value is not configured, the
network-wide default device list is used when assigning an IP
address from the subnet.
Step 18
Switch(config-dhcp-subnet-secondary)#
override utilization high
percentage-number
(Optional) Sets the high utilization mark of the subnet size.
•
This command overrides the global default setting specified
by the
utilization mark high
command.
Step 19
Switch(config-dhcp-subnet-secondary)#
override utilization low
percentage-number
(Optional) Sets the low utilization mark of the subnet size.
•
This command overrides the global default setting specified
by the
utilization mark low
command.
Step 20
Switch(config-dhcp-subnet-secondary)#
end
Exits DHCP secondary subnet configuration mode and returns to
privileged EXEC mode.
Command or Action
Purpose
Summary of Contents for Catalyst 4500 Series
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