Reducing Lookout comm failures after adding Cisco Catalyst 2955 switch

[vorlon]

After adding the aforementioned switch to our system in an attempt to reduce the number of red X's, we've found that we're actually getting *MORE*! After reading relevant Allen-Bradley KB articles for the SLC 5/05, we've determined that forcing the Cisco into 10Mbit/Half-Duplex on ports attached to the SLC should have been all that was required. However, the problem remains, and is causing drop-outs in data collection as long as 30sec at a time. There are 4 Lookout 5.0 terminals querying one SLC, a SLC/terminal pair, and another SLC coming in which will attach to the first 4 terminals. Yes, we know the 'suggested' way of doing this is one terminal running a 'server' process with the others running only
clients, but the original licensing ordered by our client precludes us from easily switching to this topology.

[JR_A.]

I'm not familiar with this since it is an AB issue, but if it is a duplexing issue you might try forcing the ethernet cards on the PC's to 10Mbit/Half-Duplex. However, most NICs are set to auto-negotiate and if the switch is forced to a setting the PCs should also be on that.

JR A.

[vorlon]

We've already forced the AB into 10Mb/Half mode (required by the SLC5/05 system). The workstations have been having this trouble whether they're forced or in auto-nego mode. I may have some useful metrics in a day or so which might help shed light on what's happening at the packet level.