1769-L32E Duplicate IP Detected errors with Cisco switch upgrade

So recently our plant upgrade the LAN managed switches to Cisco 2960-Xs.
After that, we've been experiencing the Duplicate IP Detected error that's outlined in AB KB#568750.
We have several 1769-L32Es running firmware v16.21 that are having issues.

In researching this, I've found that the Duplicate Address Detection issue is resolved on 1756-ENBT cards starting with firmware v6.001. I haven't been able to find out if there are any firmware updates for the 1769-L32Es that address this issue though.

Has anyone been able to resolve this problem with the L32Es on the PLC end or are the only fixes to change the Cisco switches config?

I'm just wanting to make sure that all of my bases are covered, as an E&I tech, before I go campaigning to corporate IT to implement one of the fixes outlined in the KB article.

Crazy question, but do you think it's possible you have an actual conflict? Think about what's changed and when you started seeing issues.

I'll put money on the problem being the cisco switches ARP request.

For some reason, older AB ethernet adapters see this request as a duplicate IP.

Edit: Just seen you linked to the KB about the issue.

Unfortunately my solution was to upgrade the CPU's to L33's as there were only a couple of L32's on site and we had spares at the factory. Couldn't try newer firmware as the client only had up to rev 20.1

We had the same issue it was solved by upgrading the firmware of processor to 19.11

Rob..
Yup, I'm fairly convinced that it is the ARP request since I've found some 0.0.0.0 traffic on some of our newer Control/CompactLogix ethernet adapters' diagnostic info pages and the timing of the issue coincides prefectly with the switch upgrade.
We've done several IP audits on the network and I am sure we don't have any actual duplicate IPs.

tarik1978 said:

We had the same issue it was solved by upgrading the firmware of processor to 19.11

Click to expand...

That sounds promising. I will look closer at the v19 firmware. We do have a spare L32 on the shelf that I can test with.


Oddly enough, we have some L32Es running v13 firmware and they haven't had any problems that we've noticed. The 3 problem children are all running v16.21 firmware.
The v13 units are on our firmware update list and I'm hesitant to update them until we can get this issue figured out.