Configuring ARP Security (ARP Anti-Spoofing)
Applicable Products and Versions
This example applies to the CE12800/CE6800/CE5800 V100R001C00 or later.
This example applies to the CE7800 V100R003C00 or later.
This example applies to the CE8800 V100R006C00 or later.
This example applies to the CE12800E V200R002C50 or later.
Networking Requirements
As shown in Figure 2-60, the switch connects to a server through 10GE1/0/3 and connects to users in VLAN 10 and VLAN 20 through 10GE1/0/1 and 10GE1/0/2. Attackers send bogus ARP packets or bogus gratuitous ARP packets to the switch to modify the ARP entries on the switch. As a result, authorized users cannot send and receive data packets.
The administrator wants to prevent the preceding ARP spoofing attacks and provide users with stable services on a secure network.
Configuration Roadmap
- Configure strict ARP learning and fixed ARP to prevent ARP entries from being modified by bogus ARP packets.
- Configure gratuitous ARP packets discarding to prevent ARP entries from being modified by bogus gratuitous ARP packets.
Procedure
- Create VLANs, add interfaces to the VLANs, and configure
VLANIF interfaces.
# Create VLAN 10, VLAN 20, and VLAN 30, add 10GE1/0/1 to VLAN 10, 10GE1/0/2 to VLAN 20, and 10GE1/0/3 to VLAN 30.
<HUAWEI> system-view [~HUAWEI] sysname Switch [*HUAWEI] commit [~Switch] vlan batch 10 20 30 [~Switch] interface 10ge 1/0/1 [~Switch-10GE1/0/1] port link-type trunk [*Switch-10GE1/0/1] port trunk allow-pass vlan 10 [*Switch-10GE1/0/1] quit [*Switch] interface 10ge 1/0/2 [*Switch-10GE1/0/2] port link-type trunk [*Switch-10GE1/0/2] port trunk allow-pass vlan 20 [*Switch-10GE1/0/2] quit [*Switch] interface 10ge 1/0/3 [*Switch-10GE1/0/3] port link-type trunk [*Switch-10GE1/0/3] port trunk allow-pass vlan 30 [*Switch-10GE1/0/3] quit [*Switch] commit
# Create VLANIF 10, VLANIF 20, and VLANIF 30, and assign IP addresses to them.
[~Switch] interface vlanif 10 [~Switch-Vlanif10] ip address 8.8.8.1 24 [*Switch-Vlanif10] quit [*Switch] interface vlanif 20 [*Switch-Vlanif20] ip address 9.9.9.1 24 [*Switch-Vlanif20] quit [*Switch] interface vlanif 30 [*Switch-Vlanif30] ip address 10.10.10.3 24 [*Switch-Vlanif30] quit [*Switch] commit
- Configure strict ARP learning.
[~Switch] arp learning strict - Configure fixed ARP.
# Enable the fixed-mac mode.
[*Switch] arp anti-attack entry-check fixed-mac enable - Configure gratuitous ARP packet discarding.
[*Switch] arp anti-attack gratuitous-arp drop [*Switch] commit
Verifying the Configuration
Run the display arp learning strict command to check the global configuration of strict ARP entry learning.
[~Switch] display arp learning strict The global arp learning strict state:enable Interface LearningStrictState ------------------------------------------------------------ ------------------------------------------------------------ Total:0 Force-enable:0 Force-disable:0Run the display arp anti-attack entry-check command to check the configuration of fixed ARP.
[~Switch] display arp anti-attack entry-check Vlanif Mode ------------------------------------------------------------------------------- All fix-mac -------------------------------------------------------------------------------Run the display arp packet statistics command to check statistics on ARP packets.
[~Switch] display arp packet statistics ARP Packets Received Total: 9253 Learnt Count: 2 Discard For Entry Limit: 0 Discard For Speed Limit: 0 Discard For Proxy Suppress: 0 Discard For Other: 0 ARP Packets Sent Total: 3359 Request: 453 Reply: 2906 Gratuitous ARP: 303 ARP-Miss Message Received Total: 16 Discard For Speed Limit: 0 Discard For Other: 0In the preceding command output, the number of ARP packets discarded by the switch is displayed, indicating that the ARP security (ARP anti-spoofing) function has taken effect.
Configuration File
# sysname Switch # vlan batch 10 20 30 # arp learning strict arp anti-attack entry-check fixed-mac enable arp anti-attack gratuitous-arp drop # interface Vlanif10 ip address 8.8.8.1 255.255.255.0 # interface Vlanif20 ip address 9.9.9.1 255.255.255.0 # interface Vlanif30 ip address 10.10.10.3 255.255.255.0 # interface 10GE1/0/1 port link-type trunk port trunk allow-pass vlan 10 # interface 10GE1/0/2 port link-type trunk port trunk allow-pass vlan 20 # interface 10GE1/0/3 port link-type trunk port trunk allow-pass vlan 30 # return
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