ARP entry shows as (incomplete) on self configured interface.

• The local IP of the interface is checked for ARP.
• This ARP entry shows incomplete.
• Global Counter display ARP being dropped due to no ARP

flow_fwd_l3_noarp 42   1 drop flow forward  Packets dropped: no ARP

• On the bellow output we can see ARP entry for interface configured on the firewall is not getting self resolved:

admin@fw-ha1(active)> show interface ethernet1/1 | match IP address
Interface IP address: 192.168.77.1/30

admin@fw-ha1(active)> show arp ethernet1/1

maximum of entries supported :      2500
default timeout:                    1800 seconds
total ARP entries in table :        1
total ARP entries shown :           1
status: s - static, c - complete, e - expiring, i - incomplete

interface         ip address      hw address        port              status   ttl  
--------------------------------------------------------------------------------
ethernet1/1       192.168.77.1    (incomplete)      ethernet1/1         i      1    

• Palo Alto Networks Firewalls.
• Supported PAN-OS.
• ARP.
• Static Routing.

• Misconfigured Static Route.
• The firewall has a next hop configured as the interface IP instead of the correct next-hop.

admin@fw-ha1(active)> show interface ethernet1/1 | match IP
Interface IP address: 192.168.77.1/30

admin@fw-ha1(active)> show routing route

flags: A:active, ?:loose, C:connect, H:host, S:static, ~:internal, R:rip, O:ospf, B:bgp, 
       Oi:ospf intra-area, Oo:ospf inter-area, O1:ospf ext-type-1, O2:ospf ext-type-2, E:ecmp, M:multicast

VIRTUAL ROUTER: default (id 1)
==========
destination                           nexthop                               metric flags      age   interface          next-AS    
0.0.0.0/0                            192.168.77.1                            10     A S              ethernet1/1                   

Configure the static route to point to the correct next hop.

Incomplete ARP Entry or Firewall Responds to Every ARP Request on the Network

Firewall is Dropping Packets from LAN for No ARP