Cannot Ping Other PCs: 3 Common Mistakes Leading to Internal Network Disconnection

Are you experiencing the issue of cannot ping other PCs on the internal network? This is a common error that prevents employees from sharing files, accessing servers, or working effectively in teams. Just last week, our IT team received dozens of tickets about similar ping failures from small and medium-sized businesses. Don’t worry, this article analyzes the root causes in depth and provides detailed troubleshooting guides to restore stable LAN connectivity without calling external technicians.

Clear Signs When Experiencing Cannot Ping Other PCs Issue

When the internal network has problems, you’ll notice familiar symptoms. Your computer cannot ping other PCs, and the ping command in Command Prompt returns “Request timed out” or “Destination host unreachable”. Try opening File Explorer to access shared folders on a colleague’s machine, and you’ll get a network error message.

Symptoms often spread: printing from other machines fails, internal management software doesn’t sync data, and even Remote Desktop is interrupted. Whether using office WiFi or wired LAN, this network ping failure can occur randomly or continuously, disrupting daily workflows. Recognizing these signs early helps you act promptly and avoid time-consuming debugging.

Three Common Mistakes Causing Cannot Ping Other PCs in LAN

Internal network disruptions aren’t random. Based on experience supporting hundreds of systems, we’ve identified 3 deadly mistakes leading to this issue. Understanding the root causes helps prevent recurrence.

Mistake 1: Mixing Dynamic and Static IP Configurations Causing Address Conflicts

Many amateur admins let DHCP auto-assign IPs to some machines while setting static IPs on servers. Result? IP conflicts, causing ping failures right from ARP resolution. For example, two machines with the same IP 192.168.1.100 will compete, leading to serious LAN problems.

To check, open CMD and type ipconfig on both machines. If subnet masks don’t match (e.g., 255.255.255.0 vs 255.255.0.0), that’s the culprit. This mistake is common in small offices without centralized IP management.

Mistake 2: Firewall Blocking ICMP Traffic Without Knowing

Windows Defender Firewall or antivirus software often blocks ICMP ports (used for ping) by default. You ping 192.168.1.10 from machine A to B, but packets are dropped silently. This is the top cause of one-way or two-way ping errors.

Additionally, VPN or proxy rules, or enterprise firewall policies combined with Group Policy on domains, complicate the issue further.

Mistake 3: Hardware Issues with Switch/Router and Loose Cables

Don’t overlook physical infrastructure! Damaged Cat5e Ethernet cables, dusty switch ports, or outdated router firmware often cause network ping failures. In large LANs, misconfigured spanning tree protocol (STP) leads to loops, broadcast storms, and complete ping drops.

We’ve seen cases where an overloaded 8-port unmanaged switch caused the entire segment to fail pinging each other despite correct IP configs.

Detailed Step-by-Step Guide to Fix Cannot Ping Other PCs

Now, let’s troubleshoot practically. Follow from easiest to hardest, applicable on Windows 10/11 or Server.

Check and Fix IP Configuration Immediately

• Open CMD as Admin: ipconfig /release then ipconfig /renew.
• Check IP conflicts: arp -a to see duplicate MAC addresses.
• Set consistent static IP: Go to Network Settings > IPv4 Properties, assign 192.168.1.x with correct gateway (usually 192.168.1.1).

If using a domain, check DNS resolution with nslookup hostname. Small errors here account for 40% of cannot ping other PCs cases.

Temporarily Disable Firewall and Check ICMP

• Control Panel > Windows Defender Firewall > Advanced Settings > Inbound Rules.
• Find “File and Printer Sharing (Echo Request – ICMPv4-In)”, enable for Private network.
• Test ping: ping -t 192.168.1.10 (use -t for continuous ping).

Note: After fixing, re-enable firewall but whitelist the correct profile. For third-party antivirus like Kaspersky, check the network shield module separately.

Advanced LAN Network Infrastructure Debugging

• Check cables: Replace with new ones, test different switch ports.
• Access router admin (usually 192.168.1.1), update firmware, disable STP if unnecessary.
• Use Wireshark to capture packets: Filter “icmp”, check if packets are sent/received.
• Flush DNS and ARP: ipconfig /flushdns, arp -d *.

If still failing, check MTU mismatch with ping -f -l 1472 192.168.1.10. Reduce MTU to 1400 if needed.

Expert Strategic Advice to Avoid Recurring LAN Problems

Temporary fixes aren’t enough. For long-term stable internal networks, deploy monitoring tools like PRTG or Zabbix to track ping latency in real-time. Set up VLANs to segment traffic and avoid broadcast storms. Regularly audit IPs with PowerShell scripts.

For businesses, outsourcing to professional IT Helpdesk services is a smart choice. Our IT Support team at IT Systems has helped hundreds of companies eliminate ping errors and LAN problems at the root, ensuring 99.9% uptime.

Periodic maintenance investment is 10 times cheaper than downtime. Contact us now for free consultation on your business network system.

Conclusion: Restore Internal Network Connectivity in Just 30 Minutes

Cannot ping other PCs is no longer a nightmare if you master the 3 mistakes above and apply the guides. From IP conflicts, firewall blocks to weak infrastructure, every issue has a specific solution. Test it today and share results in the comments below. For quick support, call IT Systems hotline – 24/7 IT support for Vietnamese businesses.