When/why would a device send a frame with ethertype 0x86dd (IPv6) but it's actually an IPv4 packet?
I've been playing around with packet captures on my local network, and I ran into an odd behavior that seems to crop up occasionally. When establishing a TCP connection to an IPv4 host, I caught my iPhone sending an Ethernet frame with type 0x86dd but encapsulating an IPv4 packet (Frame no. 3 in pcap dump). Wireshark flags this as an undecodable mess, since the IPv6 version field is set to 4. If I manually override it to decode as IPv4, then sure enough it's a valid, correct IPv4 packet.
Is this something my network should be able to handle? What should my router do with such a packet?
It seems that we don´t have the permissions to view your shared file.
Whoops! Fixed.
Looks totally strange to me. And no, your network should not be able to handle this packet (IMHO). I expect that the packet gets dropped at the next layer 3 hop (router).