Resolve Intermittent PC-to-PC Network Connectivity After ISP Equipment Changes

draft · network network-pathreachabilityfirewallisp

Generated by docuprocessor (prompt article/v3) · 2026-04-22 15:51

Source thread

thread_id: spaces/AAAA05BdS6s/threads/pkK_ztfi_WE · 21 msgs · first 2025-02-05 · participants: Tech ATech BTech CTech D

Tech A 2025-02-05 21:59

any ideas what else could I try here? I have 1 pc that cannot reach another pc in the office (frontdesk02) frontdesk02 shares a printer, and it doesn't work because I cannot reach it, already enabled SMB, I can ping/reach fine other pcs including the server. setup static ip, added fd2 pc to the host file, rebooted. nothing... I can reach fine this pc from the server, for example

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**CMD Window:** Two ping tests are visible — `ping frontdesk02` targeting `192.168.1.204` returns "Destination host unreachable" with 50% packet loss; `ping frontdesk03` targeting `192.168.1.247` succeeds with 0% packet loss and 1–3ms TTL=128 replies. **Network Error Dialog:** Error accessing `\\frontdesk02`; Error code **0x80070035**, message: *"The network path was not found."* **OS:** Windows 10 Version 10.0.19045.5440.

Tech A 2025-02-05 21:59

same pc, but from the server

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**Remote Desktop Session (LogMeIn) — Server: ROLIGO YONKERS** A CMD window running as Administrator shows a successful ping to **FRONTDESK02 [192.168.1.206]** — 4 packets sent, 4 received, 0% loss, with round-trip times of <1ms (Min=0ms, Max=0ms, Avg=0ms, TTL=128); an `ipconfig` command is queued at the prompt. A File Explorer window browsing **Network > frontdesk02** displays a single shared device: **HP LaserJet Pro M201-M202 PCL 6**.

Tech B 2025-02-05 22:08

can that PC reach itself?

Tech C 2025-02-05 22:30

Did you check if FD02 has ipv6 disabled? also check if firewall in FD2 is on, turned it off and ping again, also check if the path is correct running a tracert from SVR to fd2 and also the same from fd1 to fd2 to see if any switch or router might be the issue

Tech A 2025-02-05 22:37

yes o3o

Tech A 2025-02-05 22:38

haven't checked fd2 since it was in use, but I can reach it from any pc except FD01, for whatever reason

Tech B 2025-02-05 22:38

credential manager?

Tech B 2025-02-05 22:39

and can u ping it?

Tech A 2025-02-05 22:39

I cannot even ping host/IP from FD01 🫠

Tech A 2025-02-05 22:39

it just times out

Tech B 2025-02-05 22:40

FW might be blocking ther ping, so make sure you disable it as a test

Tech B 2025-02-05 22:40

also, on the PC you are trying to reach, do you see anything in event viewer? for example ID 2017 in particular

Tech A 2025-02-06 18:22

did not see any, so fd1 cannot reach fd2 but can reach other pcs in the office. > fd2 cannot reach fd1, times out, and even from server, I can reach fine fd2, while fd1 times out? I thought of rebooting their router last night since bitrix said they have a WG, but that might be old, since only a Optimum web page loads as default.

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**Remote Desktop Session – CMD Ping Diagnostic** A Windows Server 2019 (Version 10.0.17763.6054) command prompt is open via remote control session labeled **"ROLIGO YONKERS – SERVER."** A ping to **FRONTDESK02 (192.168.1.206)** returned 4/4 successful replies (0% packet loss, min 0ms / max 2ms / avg 0ms, TTL=128). A subsequent ping to **FRONTDESK01** resolved to **FRONTDESK01.local (192.168.1.231)** but all packets returned **"Request timed out"** (100% packet loss).

Tech A 2025-02-06 18:22

so I guess the issue specifically might be FD1 with the above said...

Tech B 2025-02-06 18:25

is Optimum pops up on all devices or just that FD1?

Tech A 2025-02-06 18:26

as default gateway you mean? I only tried from the server, 192.168.1.1 leads to an optimum sign in page

Tech A 2025-02-06 18:26

port 8080 won't load, I guess there was a WG, maybe not anymore? not really sure what happened there

Tech B 2025-02-06 18:40

@Albert Khaydatov ? are you aware?

Tech D 2025-02-06 18:52

maybe when optimum was there they caused a split network? WESTCHESTER SMILE DESIG D02C040A3-5923 May 24, 2026 T25

Tech A 2025-02-06 19:02

no idea then, I guess I will have to call and find out, maybe reboot whatever they are using and see if it helps with the issue they are having with the fd pc

Tech A 2025-02-12 20:31

this resolved itself after Anthony went there and put the WG back, Optimum was in the office a few weeks ago and they decided to to bypass the WG to put their stuff on lol

---
title: "Resolve Intermittent PC-to-PC Network Connectivity After ISP Equipment Changes"
category: network
tags: ["network-path", "reachability", "firewall", "isp"]
source_thread_id: "spaces/AAAA05BdS6s/threads/pkK_ztfi_WE"
source_space: "spaces/AAAA05BdS6s"
generated_at: "2026-04-22T15:51:43"
participants: ["Tech A", "Tech B", "Tech C", "Tech D"]
---

# Resolve Intermittent PC-to-PC Network Connectivity After ISP Equipment Changes

## Problem

A Windows 10 workstation (FRONTDESK01) could not reach another workstation (FRONTDESK02) on the same network, preventing access to a shared HP LaserJet printer. FRONTDESK01 could ping other devices including the server, but pings to FRONTDESK02 at 192.168.1.206 returned "Destination host unreachable" with 50% packet loss. Network path access attempts returned error code 0x80070035 ("The network path was not found").

The server could successfully reach FRONTDESK02, but pings from the server to FRONTDESK01 at 192.168.1.231 resulted in 100% packet loss with "Request timed out" responses. The default gateway (192.168.1.1) displayed an Optimum ISP login page instead of the expected WatchGuard firewall interface, indicating the ISP had bypassed the existing network equipment during a recent service visit.

## Resolution

1. Verify the ISP has not bypassed your firewall or router during recent service calls
2. Check if the default gateway IP still points to your firewall management interface rather than ISP equipment
3. If ISP equipment has been placed in front of your firewall, restore the original network topology by:
   - Reconnecting the WatchGuard or primary firewall as the main router
   - Ensuring ISP equipment feeds into the WAN port of your firewall
   - Verifying all workstations remain on the same subnet behind your firewall
4. Reboot network equipment after topology changes to clear any routing conflicts

The issue was resolved when a technician visited the site and restored the WatchGuard firewall to its proper position in the network topology after the ISP had bypassed it.

## References
- Source discussion: `spaces/AAAA05BdS6s/threads/pkK_ztfi_WE`
- Attachments:
  - ![image.png](../attachments/pkK_ztfi_WE.X5Kabrtmf2s/image.png) — **Remote Desktop Session – CMD Ping Diagnostic**
  - ![image.png](../attachments/pkK_ztfi_WE.pkK_ztfi_WE/image.png) — **CMD Window:** Two ping tests are visible — `ping frontdesk02` targeting `192.168.1.204` returns "Destination host unreachable" with 50% packet loss; `ping frontdesk03` targeting `192.168.1.247` succeeds with 0% packet loss and 1–3ms TTL=128 replies.
  - ![image.png](../attachments/pkK_ztfi_WE.x662ZvxOc9A/image.png) — **Remote Desktop Session (LogMeIn) — Server: ROLIGO YONKERS**

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