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On a Layer 2 Ethernet port, IP source guard cooperates with DHCP snooping, dynamically obtains the
DHCP snooping entries generated during dynamic IP address allocation, and generates IP source guard
entries accordingly.
On a Layer 3 Ethernet port or VLAN interface, IP source guard cooperates with DHCP relay, dynamically
obtains the DHCP relay entries generated during dynamic IP address allocation across network
segments, and generates IP source guard entries accordingly.
Dynamic IPv4 source guard entries can contain such information as the MAC address, IP address, VLAN
tag, ingress port information, and entry type (DHCP snooping or DHCP relay), where the MAC address,
IP address, or VLAN tag information may not be included, depending on your configuration. IP source
guard applies these entries to the port to filter packets.
To configure the IPv4 source guard function on a port:
To do…
Use the command…
Remarks
1.
Enter system view.
system-view
—
2.
Enter interface view.
interface
interface-type interface-
number
The term "interface" collectively
refers to the following types of
ports and interfaces: Bridge mode
(Layer 2) and route mode (Layer
3) Ethernet ports, VLAN
interfaces, and port groups.
You can use the
port
link-mode
command to set an Ethernet port
to operate in bridge or route
mode (see
Layer 2—LAN
Switching Configuration Guide
).
3.
Configure IPv4 source guard
on the port.
ip verify source
{
ip-address
|
ip-
address
mac-address
|
mac-
address
}
Required.
Not configured by default.
To generate IPv4 binding entries dynamically based on DHCP entries, make sure that DHCP snooping or
DHCP relay is configured and working normally. For information about DHCP snooping configuration
and DHCP relay configuration, see
Layer 3—IP Services Configuration Guide
.
If you repeatedly configure the IPv4 source guard function on a port, only the last configuration takes
effect.
Although dynamic IPv4 source guard binding entries are generated based on DHCP entries, the number
of dynamic IPv4 source guard binding entries is not necessarily the same as that of the DHCP entries.
Configuring a static IPv4 source guard binding entry
Static IPv4 binding entries take effect only on ports configured with the IPv4 source guard function (see
"
Configuring IPv4 source guard on a port
").
Configuring port-based static IPv4 binding entries
To do…
Use the command…
Remarks
1.
Enter system view.
system-view
—