The primary two strains are the system with IP handle 192.168.2.22 sending a bunch of mDNS multicast queries for PTR data of assorted providers within the native community.
PTR means the message is a few PoinTeR report, (QM) are the flags within the mDNS request packet (Question and Multicast), and the query mark simply makes it simpler to see that it is a question.
Any system offering a service of the queried sort is meant to reply with a PTR report that factors at a SRV report that describes the queried service on the responding system. This scheme is known as DNS-based Service Discovery (DNS-SD): it may be used with each mDNS and common DNS, and it is described in RFC 6763.
The service names was tracked in a short-term registry which was later merged into the Service Title and Transport Protocol Quantity Registry maintained by IANA. Within the IANA registry, you must seek for the plain service title, with the primary underscore omitted. The entry within the IANA registry is normally fairly brief, however even you then’ll normally discover at the very least a number of names or different key phrases you should use to refine your google outcomes.
PTR (QM)? _airplay._tcp.native.Any Apple AirPlay-capable video shows right here?PTR (QM)? _raop._tcp.native.Any Apple AirPlay-capable audio units right here?PTR (QM)? _sleep-proxy._udp.native.Is there a tool that would inform anybody who would possibly ask that I am nonetheless obtainable whereas I might nod off for a fast power-save nap?PTR (QM)? _uscan._tcp.native.Any HP-compatible community scanners right here?PTR (QM)? _uscans._tcp.native.Any SSL/TLS-capable HP-compatible community scanners right here?PTR (QM)? _ippusb._tcp.native.Are there any shared printers which can be utilizing the IPP-over-USB protocol, i.e. USB-connected printers shared by a Mac?PTR (QM)? _scanner._tcp.native.Are there any Bonjour-capable scanners?PTR (QM)? _ipp._tcp.native.Are there any printers utilizing the IPP protocol right here?PTR (QM)? _ipps._tcp.native.Any SSL/TLS succesful IPP printers?PTR (QM)? _printer._tcp.native.Any sorts of shared printers in any respect?PTR (QM)? _pdl-datastream._tcp.native.Any HP JetDirect-style community printers?PTR (QM)? _ptp._tcp.native.Any units supporting the Image Switch Protocol over this community?PTR (QM)? _googlecast._tcp.native.Is there a ChromeCast-capable gadget on this community?PTR (QM)? _airport._tcp.native.Any Apple AirPort WiFi APs?PTR (QM)? _privet._tcp.native.Any Google CloudPrint-capable printers or print providers?
On the final two strains, the identical gadget is sending out multicast SSDP (a HTTP-like Easy Service Discovery Protocol) messages, however tcpdump doesn’t analyze that protocol deep sufficient to inform whether or not it is querying for native providers or saying its personal community providers. A SSDP question could be step one in e.g. community uPnP, which could enable an software to request a short lived port forwarding by means of a NAT routinely if the NAT router has the uPnP characteristic enabled.
I believe these 4 strains are a reasonably typical instance of queries a smartphone or a pill would possibly make when connecting to a WiFi community.