3Com 4210G Series Configuration Manual page 237

Figure 4-2 Network diagram for ARP detection configuration
Configuration procedure
1) Add all the ports on Switch B into VLAN 10, and configure the IP address of VLAN-interface 10 on
Switch A (the configuration procedure is omitted).
2) Configure a DHCP server (the configuration procedure is omitted).
3) Configure Host A and Host B as 802.1x clients (the configuration procedure is omitted) and
configure them to upload IP addresses for ARP detection.
4) Configure Switch B
# Enable the 802.1x function.
<SwitchB> system-view
[SwitchB] dot1x
[SwitchB] interface gigabitethernet 1/0/1
[SwitchB-GigabitEthernet1/0/1] dot1x
[SwitchB-GigabitEthernet1/0/1] quit
[SwitchB] interface gigabitethernet 1/0/2
[SwitchB-GigabitEthernet1/0/2] dot1x
[SwitchB-GigabitEthernet1/0/2] quit
# Add local access user test.
[SwitchB] local-user test
[SwitchB-luser-test] service-type lan-access
[SwitchB-luser-test] password simple test
[SwitchB-luser-test] quit
# Enable ARP detection for VLAN 10. Configure the upstream port as a trusted port and the
downstream ports as untrusted ports (a port is an untrusted port by default).
[SwitchB] vlan 10
[SwitchB-vlan10] arp detection enable
[SwitchB-vlan10] interface gigabitethernet 1/0/3
[SwitchB-GigabitEthernet1/0/3] arp detection trust
[SwitchB-GigabitEthernet1/0/3] quit
# Enable ARP detection based on 802.1X security entries.
[SwitchB] arp detection mode dot1x
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