R0106-HP MSR Router Series Security Configuration Guide(V7)
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Configuring user validity check
Upon receiving an ARP packet from an ARP untrusted interface, the device matches the sender IP and
MAC addresses against the following entries:
• Static IP source guard binding entries.
• DHCP snooping entries.
If a match is found, the ARP packet is considered valid and is forwarded. If no match is found, the ARP
packet is considered invalid and is discarded.
Static IP source guard binding entries are created by using the ip source binding command. For more
information, see "Configuring IP source guard."
DHCP snooping entries are automatically generated by DHCP snooping. For more information, see
Layer 3—IP Services Configuration Guide.
Configuration guidelines
When you configure user validity check, follow these guidelines:
• Make sure at least one of static IP source guard binding entries and DHCP snooping entries is
available for user validity check. Otherwise, ARP packets received from ARP untrusted ports are
discarded.
• You must specify a VLAN for an IP source guard binding entry. Otherwise, no ARP packets can
match the IP source guard binding entry.
Configuration procedure
To configure user validity check:
Ste
p
Command
Remarks
1. Enter system view.
system-view N/A
2. Enter VLAN view.
vlan vlan-id N/A
3. Enable ARP detection.
arp detection enable By default, ARP detection is disabled.
4. Return to system view.
quit N/A
5. Enter Layer 2 Ethernet interface
view.
interface interface-type
interface-number
N/A
6. (Optional.) Configure the
interface as a trusted interface
excluded from ARP detection.
arp detection trust By default, an interface is untrusted.
Configuring ARP packet validity check
Enable validity check for ARP packets received on untrusted ports and specify the following objects to be
checked:
• src-mac—Checks whether the sender MAC address in the message body is identical to the source
MAC address in the Ethernet header. If they are identical, the packet is forwarded. Otherwise, the
packet is discarded.
• dst-mac—Checks the target MAC address of ARP replies. If the target MAC address is all-zero,
all-one, or inconsistent with the destination MAC address in the Ethernet header, the packet is
considered invalid and discarded.