Local App on Routed Network

[devo]

Hey everyone!

Does anyone have any experience getting the local app to communicate *through* multiple routers?

Our network is starting to get unmanageable at Layer 2 and we've begun moving it to a fully routed, OSPF redundant, Layer 3.

The only real problem we've run across is getting the local app to communicate over the OSPF links. I can ping the classic just fine, but it doesn't want to work with the local app. There are no NAT layers in the network, just dynamically assigned routes.

The classic is on the default 502 port. Anyone have any suggestions?

[RossW]

The classic is on the default 502 port. Anyone have any suggestions?

The classic does a UDP broadcast to 255.255.255.255 on port 4626.
In your routed network, that won't get past the router unless you've done something tricky.
I suspect the local app uses this packet to "discover" the classic(s).

(if it's purely for data collection, you could try using my newmodbus utility, as it will work over fully routed networks)

[atop8918]

Yes, Ross hit the nail on the head -- the advertise happens only on local (255.255.255.255) networks. Most routers shouldn't let universal broadcasts out.  If you specify a static route to the Classics they should work though -- add the IP address to the Application->Configuration menu and they _should_ come up.

-A