The internet works, files open, nothing looks dead - but every few seconds 3 to 4 ping packets vanish, and applications like Tally keep reconnecting. This is the hunt for that fault, in the order a support engineer actually works it.
This guide follows a real support case from the video. An accounts department user ran Tally, and after a few minutes of work Tally would start reconnecting and break his flow. Normal use looked fine. Only a continuous ping test showed the truth: 3 to 4 packets dropping together, then clean replies again. The team changed the wire first - the drops stayed. They fixed the wall IO jack and re-patched the connection - and the real culprit turned out to be a setting: the PC network adapter Speed and Duplex was configured at Mbps speeds while the switch was Gigabit-capable. Here is that whole hunt as a repeatable method.
Example only: replies run clean, then 3 to 4 requests time out together, then replies resume. That burst pattern is the fingerprint of a link-level fault, and a quick 4-packet ping will usually miss it completely.
Do not trust the standard 4-packet ping. Run ping -t 192.168.1.1 against your gateway and a second window with ping -t against the server the user actually works on, and watch for two or three minutes. In the video case, drops came in bursts of 3 to 4 - a quick test sent between bursts showed zero loss and the user looked wrong. Count the loss properly: a burst pattern points at the link itself, not at the application, not at the internet line.
Open the Ethernet status on the PC, or run Get-NetAdapter in PowerShell and read the LinkSpeed column. A gigabit PC on a gigabit switch should show 1.0 Gbps. If it shows 100 Mbps, the link has fallen back - usually a damaged cable pair or a forced setting. If the speed changes between checks, the link is renegotiating, which is exactly when packets die. This one number splits the problem in half before you touch any hardware.
This was the root cause in the video. Open Device Manager, open the network adapter properties, Advanced tab, and find Speed and Duplex. It should be Auto Negotiation. In the case, it was configured at an Mbps value while the switch was gigabit - the two ends never agreed properly, and the link dropped packets in bursts. Gigabit Ethernet is designed to negotiate; leave both the PC and the switch port on Auto unless you have a documented reason, and if one side is forced, the other side must be forced to the exact same setting.
The video team also did the physical work, and the order matters: patch lead first, then the wall IO jack, then the patch panel punch-down, then a different switch port. A loose punch-down or a jack with one tired contact gives the identical burst-drop symptom. Change one thing, then re-run the continuous ping for two minutes. Changing everything at once fixes nothing you can learn from - when the drops stop you will not know what cured them, and the fault will be back on another desk next month.
After the fix, run ping -n 200 to the gateway and to the server and read the summary line: packets sent, received, lost. Zero loss over 200 pings plus a link speed of 1.0 Gbps is a closed case. Then let the user work - in the video, the real test was Tally staying connected through a full working session, not a clean-looking screenshot. If drops continue, the remaining suspects are the cable pair quality and the switch port itself, covered in the companion guides in this series.
See the complete case live - the Tally reconnect complaint, the cable swap that did not fix it, and the adapter setting that did.
Watch Full VideoA normal ping sends only 4 packets. If the fault drops packets in bursts every few seconds, a 4-packet test can land entirely between bursts and report zero loss. Run a continuous ping with ping -t for two or three minutes, or send at least 200 packets, and count the real loss.
Yes. If the adapter is fixed at an Mbps setting while the switch expects gigabit negotiation, the two ends disagree about how the link runs. The link may come up, pass light traffic, and still drop bursts of packets - exactly the pattern in this case. Set both ends to Auto Negotiation.
That result is information, not failure: the patch lead is probably innocent. Move to the wall IO jack and patch panel termination, try another switch port, and check the adapter Speed and Duplex setting and the negotiated link speed before replacing anything else.