Can Static ARP Implement Binding of IP Addresses and MAC Addresses
Static ARP can implement binding of IP addresses and MAC addresses to prevent ARP entries from being updated by the pseudo ARP packets sent by attackers. However, even if static ARP is configured, the users who change IP addresses without permission can still access external networks. To address this problem, you must configure IP source guard (IPSG).
Dynamic ARP inspection (DAI) can also implement binding of IP addresses and MAC addresses. The application scenarios for static ARP, IPSG, and DAI are different. For details, see Table 2-5. You can deploy these functions according to service requirements.
Function |
Scenario |
Implementation |
---|---|---|
Static ARP |
Static ARP entries apply to the following scenarios:
|
Static ARP entries will not age and cannot be overridden by dynamic ARP entries. You can run the arp static command to manually configure a static ARP entry, or use automatic scanning and fixed ARP entries to batch configure static ARP entries. |
IPSG |
IPSG is used to prevent unauthorized users from forging IP addresses. For example, after IPSG is configured, the users who change IP addresses without permission on a network are not allowed to access external networks. In IP address forging scenarios, attackers use their owner MAC address but embezzle others' IP addresses for communication to obtain the attacked user's rights or the packets that should be sent to the attacked user. |
IPSG is used to check IP packets against binding tables (dynamic and static DHCP binding tables). When forwarding an
IP packet, the device compares the source IP address, source MAC address,
interface, and VLAN in the IP packet with the information in the binding
table. You can configure the parameters to be compared, for example,
the source IP address and VLAN.
When configuring IPSG, you can run the user-bind static command to configure a static binding table. |
DAI |
DAI is used to prevent Man in The Middle (MiTM) attacks. If DAI is not configured, ARP entries of authorized users on the device may be updated by the pseudo ARP packets sent by attackers. |
DAI is used to check ARP packets according to binding tables (dynamic and static DHCP binding tables). When receiving an
ARP packet, the device compares the source IP address, source MAC
address, interface, and VLAN in the ARP packet with the information
in the binding table. You can configure the parameters to be compared,
for example, the source IP address and VLAN.
When configuring DAI, you can run the user-bind static command to configure a static binding table. |