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r-tx-server-1#show arp
Protocol  Address          Age (min)  Hardware Addr   Type   Interface
Internet  10.199.0.12             0   Incomplete      ARPA
Internet  10.199.0.53             0   Incomplete      ARPA
Internet  10.20.251.30            0   Incomplete      ARPA
Internet  10.20.254.200           0   Incomplete      ARPA
Internet  10.20.254.202           0   Incomplete      ARPA
Internet  10.21.1.21              0   Incomplete      ARPA
Internet  10.23.1.54              0   Incomplete      ARPA
Internet  10.23.1.58              0   Incomplete      ARPA
Internet  10.23.1.99              0   Incomplete      ARPA
Internet  10.23.100.11            0   Incomplete      ARPA
Internet  10.34.1.192             0   Incomplete      ARPA
Internet  10.34.1.20              0   Incomplete      ARPA
Internet  10.34.1.73              0   Incomplete      ARPA
Internet  10.39.0.115             0   Incomplete      ARPA

For example Ping 

r-tx-server-1#ping 10.39.0.115

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 10.39.0.115, timeout is 2 seconds:
.....
Success rate is 0 percent (0/5)

I am confused why it's ARPA Incomplete?

Ron Maupin
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Mohammed Syed
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  • Did any answer help you? If so, you should accept the answer so that the question doesn't keep popping up forever, looking for an answer. Alternatively, you could provide and accept your own answer. – Ron Maupin Aug 15 '17 at 04:06
  • When mac address towards destination is not found then ARP incomplete message will appear – Sagar Uragonda Jan 27 '21 at 16:46

1 Answers1

2

On a Cisco device, the show arp command produces an incomplete hardware address when the device sends or sees an ARP request, but does not see a reply with the MAC address:

An incomplete ARP entry is learned through an ARP request but has not yet been completed with the MAC address of the external host.

An ARP request was sent for that address, but the host with that address is not up and running on the LAN, so there is no reply. The ARP entry will eventually time out unless there are more ARP requests for that IP address before the time has expired.

Ron Maupin
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