PROBLEM IN NETWORK AFTER INSTALLING CISCO 9407R

[pprai]

CISCO 9407R layer 3 network switch are being installed in out plant at Layer-3 for aggregation of data from 8 different networks. The different networks which are getting connected to CISCO switch are Yokogawa DCS networks running on YOKOGAWA CENTUM VP DCS Software. When networks were connected to switches, it was observed that some of the tags in Yokogawa DCS started going high and low randomly and caused unintended operation in the DCS. After observing this behavior, networks were disconnected from layer-3 switch and its configuration review was done. It was observed that the configuration of optical ports (slot 1 and slot2) were missing.

Now I am concerned about fact that if configuration of the ports on which the individual domains were connected were missing, why the tags in Individual domains went high randomly. Should it not be like no interdomain communication. Please help in this case. I want to know what can happen if the switch is not configured and later 2 networks are connected to it, would it cause disturbances in individual layer-2 networks.

[marce1000]

 - Make sure to have a minimum valid configuration on the Cisco switches and , select a VLAN for the ports used by  the YOKOGAWA equipment (e.g.)

 M.

[pprai]

Hi marce1000, is there any specific information related to Yokogawa DCS available as to how it will behave in case VLAN is not configured for its BUS-1 network. Bus-1 network of Yokogawa has IP Address of Range 172.16.XXX.XXX / 255.255.0.0 . It is having differentiation in third octet only and if connected without VLAN, i understand that they will become part of a single network. My surprise is for the fact that this caused Global Switches(terminology specific to Yokogawa DCS) go high and low.

[marce1000]

   >... related to Yokogawa DCS available as to how it will behave in case VLAN is not configured
           - Consider that being an invalid configuration on the Cisco switch , 

 M.