Dell PowerConnect B-FCXs Configuration Manual page 1390

39
Dynamic ARP inspection
Feature
Dynamic ARP Inspection
Trust setting for ports
Configuring an inspection ARP entry
Static ARP and static inspection ARP entries need to be configured for hosts on untrusted ports.
Otherwise, when DAI checks ARP packets from these hosts against entries in the ARP table, it will
not find any entries for them, and the Dell PowerConnect device will not allow and learn ARP from
an untrusted host.
When the inspection ARP entry is resolved with the correct IP/MAC mapping, its status changes
from pending to valid.
To configure an inspection ARP entry, enter a command such as the following.
PowerConnect(config)#arp 20.20.20.12
This command defines an inspection ARP entry, mapping a device IP address 20.20.20.12 with its
MAC address 0001.0002.0003. The ARP entry will be in Pend (pending) status until traffic with the
matching IP-to-MAC is received on a port.
Syntax: [no] arp <ip-addr> <mac-addr> inspection
The <ip-addr> <mac-addr> parameter specifies a device IP address and MAC address pairing.
Enabling DAI on a VLAN
DAI is disabled by default. To enable DAI on an existing VLAN, enter the following command.
PowerConnect(config)#ip arp inspection vlan 2
The command enables DAI on VLAN 2. ARP packets from untrusted ports in VLAN 2 will undergo
DAI inspection.
Syntax: [no] ip arp inspection vlan <vlan-number>
The <vlan-number> variable specifies the ID of a configured VLAN.
Enabling trust on a port
The default trust setting for a port is untrusted. For ports that are connected to host ports, leave
their trust settings as untrusted.
To enable trust on a port, enter commands such as the following .
PowerConnect(config)#interface ethernet 1/4
PowerConnect(config-if-e10000-1/4)#arp inspection trust
The commands change the CLI to the interface configuration level of port 1/4 and set the trust
setting of port 1/4 to trusted.
Syntax: [no] arp inspection trust
1348
Default
Disabled
Untrusted
0001.0002.0003 inspection
PowerConnect B-Series FCX Configuration Guide
53-1002266-01