Hi

I've just installed a Tapo D235 doorbell (hard-wired to 8v).

I already have several other Tapo cameras wired, and wireless but for the sake of this question/report I will compare to one of my C225 cameras which is on the same WIFI and network infrastructure.

So, I'm currently getting DUP ping responses from the D235.

I assign static IPs via DHCP and have checked for any IP address conflicts (none). arp table is good and there are no MAC conflicts.

To be sure of that I migrated the IP several times (with a reboot of the D235) but the issue persists.

The DUP responses are consistent.

The issue appears to be constrained only to the D235 and no other TAPO device in my network exhibits the same issue.

10.10.4.50 - Server I am testing from (Same responses from other servers in the network)

10.10.7.112 - C225 camera

10.10.7.114 - D235 camera

# ifconfig enp1s0 | grep 'inet '
        inet 10.10.4.50  netmask 255.255.252.0  broadcast 10.10.7.255
      

# From D235

# ping 10.10.7.114
PING 10.10.7.114 (10.10.7.114) 56(84) bytes of data.
64 bytes from 10.10.7.114: icmp_seq=1 ttl=255 time=172 ms
64 bytes from 10.10.7.114: icmp_seq=1 ttl=64 time=173 ms (DUP!)
64 bytes from 10.10.7.114: icmp_seq=2 ttl=255 time=1.08 ms
64 bytes from 10.10.7.114: icmp_seq=2 ttl=64 time=1.80 ms (DUP!)
64 bytes from 10.10.7.114: icmp_seq=3 ttl=255 time=1.08 ms
64 bytes from 10.10.7.114: icmp_seq=3 ttl=64 time=1.48 ms (DUP!)
64 bytes from 10.10.7.114: icmp_seq=4 ttl=255 time=1.07 ms
64 bytes from 10.10.7.114: icmp_seq=4 ttl=64 time=1.63 ms (DUP!)
64 bytes from 10.10.7.114: icmp_seq=5 ttl=255 time=1.02 ms
64 bytes from 10.10.7.114: icmp_seq=5 ttl=64 time=1.52 ms (DUP!)
64 bytes from 10.10.7.114: icmp_seq=6 ttl=255 time=1.13 ms
64 bytes from 10.10.7.114: icmp_seq=6 ttl=64 time=1.68 ms (DUP!)
^C
--- 10.10.7.114 ping statistics ---
6 packets transmitted, 6 received, +6 duplicates, 0% packet loss, time 5007ms
rtt min/avg/max/mdev = 1.018/29.911/173.082/63.868 ms

# tcpdump -lnn -vv -i any host 10.10.7.114 and icmp
tcpdump: data link type LINUX_SLL2
tcpdump: listening on any, link-type LINUX_SLL2 (Linux cooked v2), snapshot length 262144 bytes
12:49:32.817387 enp1s0 Out IP (tos 0x0, ttl 64, id 35525, offset 0, flags [DF], proto ICMP (1), length 84)
    10.10.4.50 > 10.10.7.114: ICMP echo request, id 37181, seq 1, length 64
12:49:32.818635 enp1s0 In  IP (tos 0x0, ttl 255, id 35525, offset 0, flags [DF], proto ICMP (1), length 84)
    10.10.7.114 > 10.10.4.50: ICMP echo reply, id 37181, seq 1, length 64
12:49:32.819350 enp1s0 In  IP (tos 0x0, ttl 64, id 11386, offset 0, flags [none], proto ICMP (1), length 84)
    10.10.7.114 > 10.10.4.50: ICMP echo reply, id 37181, seq 1, length 64
12:49:33.647378 enp1s0 Out IP (tos 0x0, ttl 64, id 35872, offset 0, flags [DF], proto ICMP (1), length 84)
    10.10.4.50 > 10.10.7.114: ICMP echo request, id 37181, seq 2, length 64
12:49:33.648420 enp1s0 In  IP (tos 0x0, ttl 255, id 35872, offset 0, flags [DF], proto ICMP (1), length 84)
    10.10.7.114 > 10.10.4.50: ICMP echo reply, id 37181, seq 2, length 64
12:49:33.649137 enp1s0 In  IP (tos 0x0, ttl 64, id 11387, offset 0, flags [none], proto ICMP (1), length 84)
    10.10.7.114 > 10.10.4.50: ICMP echo reply, id 37181, seq 2, length 64
12:49:34.648458 enp1s0 Out IP (tos 0x0, ttl 64, id 36773, offset 0, flags [DF], proto ICMP (1), length 84)
    10.10.4.50 > 10.10.7.114: ICMP echo request, id 37181, seq 3, length 64
12:49:34.649503 enp1s0 In  IP (tos 0x0, ttl 255, id 36773, offset 0, flags [DF], proto ICMP (1), length 84)
    10.10.7.114 > 10.10.4.50: ICMP echo reply, id 37181, seq 3, length 64
12:49:34.649906 enp1s0 In  IP (tos 0x0, ttl 64, id 11388, offset 0, flags [none], proto ICMP (1), length 84)
    10.10.7.114 > 10.10.4.50: ICMP echo reply, id 37181, seq 3, length 64
12:49:35.650125 enp1s0 Out IP (tos 0x0, ttl 64, id 37411, offset 0, flags [DF], proto ICMP (1), length 84)
    10.10.4.50 > 10.10.7.114: ICMP echo request, id 37181, seq 4, length 64
12:49:35.651151 enp1s0 In  IP (tos 0x0, ttl 255, id 37411, offset 0, flags [DF], proto ICMP (1), length 84)
    10.10.7.114 > 10.10.4.50: ICMP echo reply, id 37181, seq 4, length 64
12:49:35.651716 enp1s0 In  IP (tos 0x0, ttl 64, id 11389, offset 0, flags [none], proto ICMP (1), length 84)
    10.10.7.114 > 10.10.4.50: ICMP echo reply, id 37181, seq 4, length 64
12:49:36.652034 enp1s0 Out IP (tos 0x0, ttl 64, id 37723, offset 0, flags [DF], proto ICMP (1), length 84)
    10.10.4.50 > 10.10.7.114: ICMP echo request, id 37181, seq 5, length 64
12:49:36.653019 enp1s0 In  IP (tos 0x0, ttl 255, id 37723, offset 0, flags [DF], proto ICMP (1), length 84)
    10.10.7.114 > 10.10.4.50: ICMP echo reply, id 37181, seq 5, length 64
12:49:36.653520 enp1s0 In  IP (tos 0x0, ttl 64, id 11390, offset 0, flags [none], proto ICMP (1), length 84)
    10.10.7.114 > 10.10.4.50: ICMP echo reply, id 37181, seq 5, length 64
12:49:37.653798 enp1s0 Out IP (tos 0x0, ttl 64, id 38124, offset 0, flags [DF], proto ICMP (1), length 84)
    10.10.4.50 > 10.10.7.114: ICMP echo request, id 37181, seq 6, length 64
12:49:37.654890 enp1s0 In  IP (tos 0x0, ttl 255, id 38124, offset 0, flags [DF], proto ICMP (1), length 84)
    10.10.7.114 > 10.10.4.50: ICMP echo reply, id 37181, seq 6, length 64
12:49:37.655442 enp1s0 In  IP (tos 0x0, ttl 64, id 11391, offset 0, flags [none], proto ICMP (1), length 84)
    10.10.7.114 > 10.10.4.50: ICMP echo reply, id 37181, seq 6, length 64
^C
18 packets captured
50 packets received by filter
0 packets dropped by kernel

#################################################

# From C225

# ping 10.10.7.112
PING 10.10.7.112 (10.10.7.112) 56(84) bytes of data.
64 bytes from 10.10.7.112: icmp_seq=1 ttl=64 time=2.45 ms
64 bytes from 10.10.7.112: icmp_seq=2 ttl=64 time=2.73 ms
64 bytes from 10.10.7.112: icmp_seq=3 ttl=64 time=10.0 ms
64 bytes from 10.10.7.112: icmp_seq=4 ttl=64 time=5.45 ms
64 bytes from 10.10.7.112: icmp_seq=5 ttl=64 time=2.92 ms
64 bytes from 10.10.7.112: icmp_seq=6 ttl=64 time=2.34 ms
^C
--- 10.10.7.112 ping statistics ---
6 packets transmitted, 6 received, 0% packet loss, time 5007ms
rtt min/avg/max/mdev = 2.340/4.314/9.998/2.751 ms

# tcpdump -lnn -vv -i any host 10.10.7.112 and icmp
tcpdump: data link type LINUX_SLL2
tcpdump: listening on any, link-type LINUX_SLL2 (Linux cooked v2), snapshot length 262144 bytes
12:51:18.851503 enp1s0 Out IP (tos 0x0, ttl 64, id 11517, offset 0, flags [DF], proto ICMP (1), length 84)
    10.10.4.50 > 10.10.7.112: ICMP echo request, id 37235, seq 1, length 64
12:51:18.853921 enp1s0 In  IP (tos 0x0, ttl 64, id 54067, offset 0, flags [none], proto ICMP (1), length 84)
    10.10.7.112 > 10.10.4.50: ICMP echo reply, id 37235, seq 1, length 64
12:51:19.853213 enp1s0 Out IP (tos 0x0, ttl 64, id 11701, offset 0, flags [DF], proto ICMP (1), length 84)
    10.10.4.50 > 10.10.7.112: ICMP echo request, id 37235, seq 2, length 64
12:51:19.855904 enp1s0 In  IP (tos 0x0, ttl 64, id 54167, offset 0, flags [none], proto ICMP (1), length 84)
    10.10.7.112 > 10.10.4.50: ICMP echo reply, id 37235, seq 2, length 64
12:51:20.855140 enp1s0 Out IP (tos 0x0, ttl 64, id 11843, offset 0, flags [DF], proto ICMP (1), length 84)
    10.10.4.50 > 10.10.7.112: ICMP echo request, id 37235, seq 3, length 64
12:51:20.865095 enp1s0 In  IP (tos 0x0, ttl 64, id 54182, offset 0, flags [none], proto ICMP (1), length 84)
    10.10.7.112 > 10.10.4.50: ICMP echo reply, id 37235, seq 3, length 64
12:51:21.856361 enp1s0 Out IP (tos 0x0, ttl 64, id 12595, offset 0, flags [DF], proto ICMP (1), length 84)
    10.10.4.50 > 10.10.7.112: ICMP echo request, id 37235, seq 4, length 64
12:51:21.861779 enp1s0 In  IP (tos 0x0, ttl 64, id 54248, offset 0, flags [none], proto ICMP (1), length 84)
    10.10.7.112 > 10.10.4.50: ICMP echo reply, id 37235, seq 4, length 64
12:51:22.858014 enp1s0 Out IP (tos 0x0, ttl 64, id 13047, offset 0, flags [DF], proto ICMP (1), length 84)
    10.10.4.50 > 10.10.7.112: ICMP echo request, id 37235, seq 5, length 64
12:51:22.860908 enp1s0 In  IP (tos 0x0, ttl 64, id 54256, offset 0, flags [none], proto ICMP (1), length 84)
    10.10.7.112 > 10.10.4.50: ICMP echo reply, id 37235, seq 5, length 64
12:51:23.858447 enp1s0 Out IP (tos 0x0, ttl 64, id 13871, offset 0, flags [DF], proto ICMP (1), length 84)
    10.10.4.50 > 10.10.7.112: ICMP echo request, id 37235, seq 6, length 64
12:51:23.860756 enp1s0 In  IP (tos 0x0, ttl 64, id 54318, offset 0, flags [none], proto ICMP (1), length 84)
    10.10.7.112 > 10.10.4.50: ICMP echo reply, id 37235, seq 6, length 64
^C
12 packets captured
16 packets received by filter
0 packets dropped by kernel

Any thoughts? I've pretty much exhausted my own testing and analysis. Various reboots and wifi reconnects have not resolved the issue. Neither has switching bands or WAP locations.

For clarity, the doorbell *seems* to work fine but I would be keen to understand what may be causing this erroneous reporting in case it is indicitive of a larger issue.

Many thanks in advance

EDIT: I've also tried un-pairing the chime in case there was some weird virtual adapter stuff going on internally in the D235. No change.