Solved Unknown Devices or...?

[skeal]

I have the client list bug on my AX88U. I use arp -a to list devices in the meantime. When I run arp -a my output includes this:

? (192.168.50.77) at <incomplete>  on br0
KSC.myhome.lan (192.168.50.52) at 00:02:d1:**.**.** [ether]  on br0
Q60.myhome.lan (192.168.50.39) at ac:f6:f7:**.**.** [ether]  on br0
YardCam.myhome.lan (192.168.50.54) at 00:02:d1:**.**.** [ether]  on br0
? (192.168.50.16) at <incomplete>  on br0

Can someone tell me what the entries with <incomplete> are?

 

[ColinTaylor]

It means that a device with that IP address was previously connected but is no longer responding to arp requests (probably because it's turned off or disconnected). After a while the incomplete entry will be removed.

EDIT: Technically speaking the device doesn't even have to ever existed. You can just ping a nonexistent address and it will create an incomplete arp entry.

 

[oso2276]

EDIT: Technically speaking the device doesn't even have to ever existed. You can just ping a nonexistent address and it will create an incomplete arp entry.

Good sharing
Thanks [emoji106]

Enviado desde mi moto g(8) plus mediante Tapatalk

 

[chongnt]

It means that a device with that IP address was previously connected but is no longer responding to arp requests (probably because it's turned off or disconnected). After a while the incomplete entry will be removed.

EDIT: Technically speaking the device doesn't even have to ever existed. You can just ping a nonexistent address and it will create an incomplete arp entry.

Thanks for pointing this out. I have the exact issue not sure where the incomplete arp entry comes from. It appears the router itself keep looking for this ip. Now I need to find where this come from.

admin@RT-AC86U-DBA8:/jffs/scripts/custom# tcpdump -n -i br0 | grep 192.168.1.202
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on br0, link-type EN10MB (Ethernet), capture size 262144 bytes
17:29:28.786926 ARP, Request who-has 192.168.1.202 tell 192.168.1.1, length 28
17:29:29.779243 ARP, Request who-has 192.168.1.202 tell 192.168.1.1, length 28
17:29:30.779241 ARP, Request who-has 192.168.1.202 tell 192.168.1.1, length 28
..snipped...

Update: Found the culprit in nvram get webdav_smb_pc. One of my old laptop entry is there.