Network Traffic

Greetings,

Scenario 1:

Host A,B: Solaris 2.6, Informix 7.24 Engine.
Router 1, 2, 3, 4 : Cisco routers 4700 and 7200 series.

(I hope my drawing is accurate enough).

[1] If informix database is on Host B and GUI application, which accesses the
informix database on Host A, is on Host B, could we determine the traffic on the
LAN that is shared by these two hosts? Without using a network analyzer, could
we could run unix commands on Host A or B to determine the traffic on Subnet A?
Could we determine how much traffic is dedicated to the GUI application
accessing the informix database?

Subnet A Subnet F

                                                  >
                                                  >
----Router 1 |----Router 4
                                                  >
                                                  >
----Host A |----Host D
             Subnet C Subnet D |
e0 e1 |-WAN-| e1 e0|
----Host B--| | | |--Host C--|
           >-Router 2-| |-Router 3-| |
          Subnet B Subnet E

Scenario 2:

Same topology as above, but Host A gets database information from Host C,
assuming there exists static routes and IP forwarding information, could we
run unix commands to determine traffic on Subnet A, B?

Thanks in advance.

Pete.