________
                                          +------------+        /
                                          |            |       |
                            +-------------+ router 1   +-------
        __                  |             |            |     /
    ___/  \_         +------+-------+     +------------+    |
  _/        \__      |     if1      |                      /
 /             \     |              |                      |
| linux    eth0 -----+ switch vlan2 |                      |     Internet
 \_ gateway    __/   |              |                      |
   \__     __/       |     if2      |                      \
      \___/          +------+-------+     +------------+    |
                            |             |            |     \
                            +-------------+ router  2  +-------
                                          |            |       |
                                          +------------+        \________