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# Solvang Water Network
> **Thread Summary:** Kevin Seifert raised a concern about Solvang's network security after increased cyber attacks on AB PLCs, asking if the PLCs were directly accessible from the internet and if they could be isolated without cutting internet access to the SCADA PC. John Bowers responded that the PLCs are connected via a Verizon DSL modem to a Phoenix switch and suggested a potential quick solution: disconnecting the DSL modem's link to the Phoenix switch and adding a second network interface card or USB adapter to the SCADA PC to maintain minimal segregation. The team is still documenting the setup, but this approach could provide a basic network isolation to improve security.
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## 1. From: Kevin Seifert <kevin@autosysnet.com> — Tue, 7 Apr 2026 22:44:47 +0000
Hey guys.
As you saw, Solvang is asking me about their network security due to the reported increases in cyber attacks on AB PLCs.
Am I correct in saying that we found the PLCs are in direct access of the internet?
If yes, can we isolate the PLCs quickly without removing internet access to the SCADA PC?
Kevin Seifert
![[20260407_19d6a1ebc6b5_Outlook-2wia2gth.png]]
AutoSys LLC
kevin@autosysnet.com<mailto:kevin@autosysnet.com>
805-835-9595
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## 2. From: John Bowers <jbowers@spiceintegration.com> — Tue, 7 Apr 2026 15:56:01 -0700
Hello Kevin,
We are still putting documentation together, but I think we plausibly have
an easy route for that from what's been connected.
It looks like the Verizon DSL device on the shelf below the Sierra wireless
box has a cable from it to the green Phoenix switch in the Sierra wireless
box. The SCADA then also connects to that DSL modem for Internet.
We can possibly remove the connection from the DSL modem to the Phoenix
contact switch, and then put a second nic card (or USB to nic adapter) on
the SCADA PLC to connect to the Phoenix switch, we would probably have a
bare minimum poormans segregation going.
John Bowers
SPICE Integration
SCADA & PLC Developer
O: 805.464.4111
C: 805.471.9105
C-10 License: 1110179
California Small Business Certification ID: 2036507
On Tue, Apr 7, 2026, 3:44 PM Kevin Seifert <kevin@autosysnet.com> wrote:
> Hey guys.
>
> As you saw, Solvang is asking me about their network security due to the
[... earlier replies trimmed ...]
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