Device behaviors

Recording observations about the behavior of different devices.

AXIS Cameras

Testing done 7/9/2021 with two AXIS M2026-LE MkII cameras running firmware version 8.40.3.

What do we learn from this testing?

At times, the AXIS Device Manager doesn't properly detect one or more cameras connected to the network. The AXIS IP Utility so far has not failed in detecting cameras. There are alternate ways to detect and access these cameras.

Behavior on boot

AXIS IP Utility

The AXIS IP Utility uses MDNS requests to discover cameras on the network. These MDNS requests are responded to by the Bonjour service running on the camera. If the Bonjour service is disabled, no response will be given.

Multiple UDP requests with different PTR queries are sent to the multicast address The following requests were sent from the test computer to the diagnostic network with two cameras attached.

Cameras respond to the queries by sending an MDNS response to the multicast address. The following are the responses from the two cameras connected to the diagnostic test network:

You can see that both camera responses shown above list all of the IP addresses instantiated on the camera.

AXIS Device Manager (ADM)

The AXIS Device Manager uses MDNS requests and SSDP requests to discover cameras on the network.

Using the ADM to configure a device makes more changes than just assigning the IP address. I believe multiple services are disabled, but this is still to be tested.

- more content to come

Alternate detection methods

Windows ARP Cache

Running "arp -a" on a Windows computer will display the arp cache. The link-local IP addresses instantiated by the ZeroConf service of recently booted cameras should be visible in the ARP list.

Packet sniffing using Wireshark

Wireshark can be used to observe broadcast/multicast traffic generated by cameras (especially prevalent during the initial boot) as well as ongoing DHCP requests if the camera is connected to a network lacking a DHCP server.