There's a topic on FreeBSD forums, which confirms this and once again explain
the configuration with which this problem occuring, and in in great detail, but
author has "solved" his problem by simply not using configuration when you
bridge physical interface with jail's VNET interface and not using jail's VNET
interface with VLANs.
I'll add some more observation here. I recreated configuration in a virtual
machine, as i wrote in my last message to freebsd-net@ here:
Jail's vlan interface IP is 10.15.15.2 and host's vlan interface IP is
10.15.15.1. Both jail and host have no ARP entries about each other addresses.