22-18
Catalyst 3750-E and 3560-E Switch Software Configuration Guide
OL-9775-08
Chapter 22 Configuring DHCP Features and IP Source Guard
Configuring IP Source Guard
Configuring IP Source Guard
•
Default IP Source Guard Configuration, page 22-18
•
IP Source Guard Configuration Guidelines, page 22-18
•
Enabling IP Source Guard, page 22-19
•
Configuring IP Source Guard for Static Hosts, page 22-20
Default IP Source Guard Configuration
By default, IP source guard is disabled.
IP Source Guard Configuration Guidelines
•
You can configure static IP bindings only on nonrouted ports. If you enter the
ip source binding
mac-address
vlan
vlan-id ip-address
interface
interface-id
global configuration command on a
routed interface, this error message appears:
Static IP source binding can only be configured on switch port.
•
When IP source guard with source IP filtering is enabled on an interface, DHCP snooping must be
enabled on the access VLAN for that interface.
•
If you are enabling IP source guard on a trunk interface with multiple VLANs and DHCP snooping
is enabled on all the VLANs, the source IP address filter is applied on all the VLANs.
Note
If IP source guard is enabled and you enable or disable DHCP snooping on a VLAN on the
trunk interface, the switch might not properly filter traffic.
•
If you enable IP source guard with source IP and MAC address filtering, DHCP snooping and port
security must be enabled on the interface. You must also enter the
ip dhcp snooping information
option
global configuration command and ensure that the DHCP server supports option 82. When
IP source guard is enabled with MAC address filtering, the DHCP host MAC address is not learned
until the host is granted a lease. When forwarding packets from the server to the host, DHCP
snooping uses option-82 data to identify the host port.
•
When configuring IP source guard on interfaces on which a private VLAN is configured, port
security is not supported.
•
IP source guard is not supported on EtherChannels.
•
You can enable this feature when 802.1x port-based authentication is enabled.
•
If the number of ternary content addressable memory (TCAM) entries exceeds the maximum, the
CPU usage increases.
•
In a switch stack, if IP source guard is configured on a stack member interface and you remove the
the configuration of that switch by entering the
no
switch
stack-member-number
provision
global
configuration command, the interface static bindings are removed from the binding table, but they
are not removed from the running configuration. If you again provision the switch by entering the
switch
stack-member-number
provision
command, the binding is restored.
Содержание Catalyst 3750-E Series
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