+----switch---------+
subnet                 |                   |
10.10.1.1/24-----------= vlan1             |
                    \  |                   |
subnet              |  |                   |
10.10.2.1/24-----------= vlan2             |
                  \ |  |                   |
subnet            | |  |                   |
10.10.3.1/24-----------= vlan3             |
                \ | |  |                   |
subnet          | | |  |                   |
10.10.4.1/24-----------= vlan4             |
              \ | | |  |                   |   +----NetBSD router-----------+
              | | | |  |                   |   |                            |
              | | | |  | 192.168.2.2 trunk =---= wm1 192.168.1.1            |
              | | | |  +-------------------+   |                            |
              | | | |                          |                            |
              | | | \--------------------------~ vlan1 10.10.1.1 parent wm1 |
              | | |                            |                            |
              | | \----------------------------~ vlan2 10.10.2.1 parent wm1 |
              | |                              |                            |
              | \------------------------------~ vlan3 10.10.3.1 parent wm1 |
              |                                |                            |
              \--------------------------------~ vlan4 10.10.4.1 parent wm1 |
                                               |                            |
                                internet-------= wm0 1.2.3.4                |
                                               +----------------------------+