Configuring Arp Scanning And Fixed Arp - HPE Moonshot 45Gc Security Configuration Manual

[SwitchB-FortyGigE1/1/3] quit
# Enable ARP detection for user validity check.
[SwitchB] vlan 10
[SwitchB-vlan10] arp detection enable
# Configure FortyGigE 1/1/3 as an ARP-trusted port.
[SwitchB-vlan10] interface fortygige 1/1/3
[SwitchB-FortyGigE1/1/3] arp detection trust
[SwitchB-FortyGigE1/1/3] quit
# Configure a static IP source guard entry on interface FortyGigE 1/1/2.
[SwitchB] interface fortygige 1/1/2
[SwitchB-FortyGigE1/1/2] ip source binding ip-address 10.1.1.6 mac-address
0001-0203-0607 vlan 10
[SwitchB-FortyGigE1/1/2] quit
# Enable ARP packet validity check by checking the MAC addresses and IP addresses of ARP
packets.
[SwitchB] arp detection validate dst-mac ip src-mac
# Configure port isolation.
[SwitchB] port-isolate group 1
[SwitchB] interface fortygige 1/1/1
[SwitchB-FortyGigE1/1/1] port-isolate enable group 1
[SwitchB-FortyGigE1/1/1] quit
[SwitchB] interface fortygige 1/1/2
[SwitchB-FortyGigE1/1/2] port-isolate enable group 1
[SwitchB-FortyGigE1/1/2] quit
After the configurations are completed, Switch B first checks the validity of ARP packets
received on interfaces FortyGigE 1/1/1 and FortyGigE 1/1/2. If the ARP packets are confirmed
as valid, the switch performs user validity check by using the static IP source guard bindings
and DHCP snooping entries. However, ARP broadcast requests sent from Host A can pass the
check on Switch B and reach Host B. Port isolation fails.
# Enable ARP restricted forwarding.
[SwitchB] vlan 10
[SwitchB-vlan10] arp restricted-forwarding enable
[SwitchB-vlan10] quit
After the configuration is completed, Switch B forwards ARP broadcast requests from Host A to
Switch A through the trusted interface FortyGigE 1/1/3. Host B cannot receive such packets.
Port isolation works correctly.

Configuring ARP scanning and fixed ARP

ARP scanning is typically used together with the fixed ARP feature in small-scale networks.
ARP scanning automatically creates ARP entries for devices in an address range. The device
performs ARP scanning in the following steps:
1. Sends ARP requests for each IP address in the address range.
2. Obtains their MAC addresses through received ARP replies.
3. Creates dynamic ARP entries.
Fixed ARP converts existing dynamic ARP entries (including those generated through ARP scanning)
to static ARP entries. This feature prevents ARP entries from being modified by attackers. Static
ARP entries can also be manually configured by the arp static command.
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