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athirat
Staff
Staff
October 7, 2016

Technical Tip: How to add static ARP entry in IPv4 and Neighbor Cache in IPv6

  • October 7, 2016
  • 0 replies
  • 38835 views

Description

 
This article describes to add static/persistent IP/MAC address bindings on the FortiGate for both IPv4 and IPv6.
 
Scope
 
FortiGate.


Solution


For both IPv4 and IPv6, persistent and static IP/MAC associations must be configured from the CLI:

For IPv4:
 
config system arp-table
    edit <id>
        set interface <interface_name>
        set ip <ip_address>
        set mac <mac_address>
    next
end
 
Example:
 
FortiGate # show system arp-table
config system arp-table
    edit 1
        set interface internal
        set ip 192.168.1.50
        set mac 00:00:5E:00:53:00
    next
end
 
For IPv6:
To configure IPv6/MAC bindings that will persist between reboots of the FortiGate:
 
config system ipv6-neighbor-cache
    edit <id>
        set interface <interface_name>
        set ipv6 <ip_address>
        set mac <mac_address>
    next
end
 
Example:
 
FortiGate # show system ipv6-neighbor-cache
config system ipv6-neighbor-cache
    edit 1
        set interface internal
        set ipv6 2001:db8:1::50
        set mac 00:00:5E:00:53:00
    next
end
 
The FortiGate also supports adding/removing non-persistent manual entries for ARP (IPv4) and the neighbor-cache (IPv6) using the following commands (these will be lost if the FortiGate reboots):
 
IPv4:
 
diagnose ip arp list
diagnose ip arp add <interface_name> <ip_address> <mac_address>
diagnose ip arp delete <interface_name> <ip_address> <mac_address>
 
IPv6:
 
diagnose ipv6 neighbor-cache list
diagnose ipv6 neighbor-cache flush
diagnose ipv6 neighbor-cache add <interface_name> <ipv6_address> <mac_address>
diagnose ipv6 neighbor-cache delete <interface_name> <ipv6_address> <mac_address>

Verification of Configuration and Troubleshooting:
To verify the existing ARP entries in IPv4:
 
FortiGate # get system arp
Address            Age(min)         Hardware Addr               Interface
192.168.1.50       -                00:00:5E:00:53:00           internal
 
To verify the existing Neighbor Cache entries in IPv6:
 
FortiGate # diagnose ipv6 neighbor-cache list
ifindex=3 ifname=internal 2001:db8:1::50 00:00:5E:00:53:00 state=00000080 use=942 confirm=942 update=942 ref=0
 
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