Kip Williams
Member
I have a process network connected together with N-Tron unmanaged switches consisting of two CompactLogix PLCs, a 1794-AENT remote IO rack, two red Lion HMIs, and a gateway rack (ENBT&DHRIO) that’s talking to 4 SLC 5/04s over DH+. The network is then connected back through a Cisco Catalyst 2960 switch over VPN to a SCADA system running on a server 300 miles away. This system has been running flawlessly for about 5 years, and then about a month ago we started receiving duplicate IP errors on both the gateway rack AND the remote IO rack (there are no duplicate IPs). The system runs fine if we disconnect it from the Cisco switch and the SCADA but if we connect either the gateway rack OR the remote IO rack back to the switch then we get a dup error on the connected device.
I am completely aware of the service bulletin regarding Cisco or Stratix switches with IP device tracking.. however there have been no recent changes made to the network or updates to the switch (the last power cycle was over 6 months ago). Additionally, we have checked switch settings and confirmed that this isn’t the issue…
However, I’m now wondering if it's possible for a switch or router on the ISPs network to be causing this issue. AB tech support says no, but I’m at a complete loss about what else it could be. And if this something caused by something outside of my control, what's the solution... other than 300 miles of cable or moving the server to the remote facility.
I am completely aware of the service bulletin regarding Cisco or Stratix switches with IP device tracking.. however there have been no recent changes made to the network or updates to the switch (the last power cycle was over 6 months ago). Additionally, we have checked switch settings and confirmed that this isn’t the issue…
However, I’m now wondering if it's possible for a switch or router on the ISPs network to be causing this issue. AB tech support says no, but I’m at a complete loss about what else it could be. And if this something caused by something outside of my control, what's the solution... other than 300 miles of cable or moving the server to the remote facility.