Network Troubleshooting Guide

Expert solutions for common network issues: IP conflicts, DHCP problems, DNS errors, and connectivity troubleshooting

🔍 Quick Network Diagnostic

Start troubleshooting by checking your current network configuration:

1️⃣

Open our IP checker extension to see your current network settings

2️⃣

Note your public IP, location, ISP, and private IP addresses

3️⃣

Compare against expected values and look for anomalies

Common Network Issues & Solutions

🔴 IP Address Conflicts

Symptoms:

  • Multiple devices showing the same private IP
  • Intermittent connectivity issues
  • Network adapter errors or warnings
  • "IP address conflict detected" messages

Diagnosis Using IP Checker:

  • Check if your device shows multiple identical private IPs
  • Look for IP addresses outside your expected subnet range
  • Verify each network adapter has a unique IP

Solutions:

  1. Restart Network Adapter: Disable and re-enable in Windows/Mac settings
  2. Release/Renew IP: Use ipconfig /release && ipconfig /renew (Windows) or sudo dhclient -r && sudo dhclient (Linux)
  3. Change Router DHCP Range: Modify DHCP pool in router settings
  4. Set Static IP: Assign manual IP outside DHCP range
  5. Restart Router: Power cycle router to clear DHCP table

🟠 DHCP Problems

Symptoms:

  • Getting 169.254.x.x (APIPA) address
  • No IP address assigned to network adapter
  • Cannot connect to router or internet
  • Network shows "Limited connectivity"

Diagnosis Using IP Checker:

  • Check if private IP shows 169.254.x.x range
  • Look for missing or unusual IP assignments
  • Verify expected private IP ranges (192.168.x.x, 10.x.x.x)

Solutions:

  1. Restart DHCP Client: Restart network services or reboot device
  2. Check Router DHCP: Ensure DHCP is enabled in router settings
  3. Expand DHCP Pool: Increase available IP addresses in router
  4. Clear DHCP Reservations: Remove unused static assignments
  5. Factory Reset Router: Last resort - reset router to defaults

🟡 DNS Resolution Issues

Symptoms:

  • IP checker shows wrong location for your ISP
  • Cannot access websites by name but IP addresses work
  • Slow website loading or timeouts
  • Some websites work while others don't

Diagnosis Using IP Checker:

  • Check if location matches your ISP's expected region
  • Verify ISP information appears correctly
  • Compare results with/without VPN to isolate DNS issues

Solutions:

  1. Flush DNS Cache: ipconfig /flushdns (Windows) or sudo dscacheutil -flushcache (Mac)
  2. Change DNS Servers: Use 8.8.8.8/8.8.4.4 (Google) or 1.1.1.1/1.0.0.1 (Cloudflare)
  3. Restart DNS Service: Restart DNS client service
  4. Check Router DNS: Verify router DNS settings
  5. Disable DNS over HTTPS: Temporarily disable DoH in browser

🔵 VPN Connection Problems

Symptoms:

  • VPN connected but real location still shows
  • Real ISP visible instead of VPN provider
  • Inconsistent location information
  • Some traffic routing outside VPN tunnel

Diagnosis Using IP Checker:

  • Compare location before/after VPN connection
  • Check if ISP shows VPN provider name
  • Look for multiple IPs suggesting split routing

Solutions:

  1. Check Kill Switch: Ensure VPN kill switch is enabled
  2. Disable Split Tunneling: Route all traffic through VPN
  3. Change VPN Protocol: Try OpenVPN, WireGuard, or IKEv2
  4. Fix DNS Leaks: Use VPN provider's DNS servers
  5. Disable IPv6: Prevent IPv6 leaks if VPN doesn't support it

Advanced Network Diagnostics

🔬 Network Interface Analysis

Use IP checker's private network scanning to identify complex issues:

  • Multiple Adapters: Check for conflicts between WiFi, Ethernet, VPN interfaces
  • Virtual Networks: Identify Docker, VM, or virtualization network issues
  • Bridge Connections: Detect network bridging problems
  • Tunnel Interfaces: Verify VPN and proxy tunnel configurations

📊 Connection Performance Issues

Diagnose speed and reliability problems:

  • ISP Throttling: Check if ISP information changes unexpectedly
  • Proxy Detection: Look for proxy or caching services in ISP data
  • Load Balancing: Identify if traffic routes through multiple providers
  • Geographic Routing: Verify traffic takes expected paths

🌐 IPv6 Connectivity Issues

Troubleshoot dual-stack network problems:

  • IPv6 Preference: Check if IPv6 takes priority over IPv4
  • Tunnel Mechanisms: Identify 6to4, Teredo, or other tunnels
  • Privacy Extensions: Verify IPv6 privacy address behavior
  • Dual-Stack Issues: Diagnose IPv4/IPv6 coexistence problems

Enterprise Network Troubleshooting

🏢 Corporate Network Issues

Common Problems:

  • Proxy Authentication: IP checker shows proxy server instead of ISP
  • Network Segmentation: Unexpected subnet assignments
  • Load Balancer Issues: Inconsistent external IP addresses
  • Firewall Blocks: Limited connectivity or filtered traffic

Troubleshooting Steps:

  1. Verify network segment assignment using private IP ranges
  2. Check if corporate proxy is properly configured
  3. Test from different network segments or VLANs
  4. Coordinate with IT to verify firewall rules

🔐 Remote Access Problems

Common Problems:

  • VPN Split Tunneling: Some traffic bypasses corporate VPN
  • DNS Resolution: Corporate resources unreachable
  • Authentication Issues: Network credentials not working
  • Policy Violations: Security policies blocking access

Troubleshooting Steps:

  1. Verify VPN connection shows corporate network location
  2. Check if ISP shows corporate provider or VPN service
  3. Test access to internal resources using private IPs
  4. Confirm all traffic routes through corporate infrastructure

Network Issue Prevention

🛡️ Proactive Monitoring

  • Regular IP checks to establish network baselines
  • Monitor for unexpected location or ISP changes
  • Document normal network configurations
  • Set up alerts for critical network changes

⚙️ Configuration Best Practices

  • Use static IP assignments for critical devices
  • Implement proper DHCP reservation policies
  • Regularly update router and network firmware
  • Document network topology and IP allocations

🔍 Regular Testing

  • Weekly VPN connection verification
  • Monthly network configuration audits
  • Quarterly security and privacy assessments
  • Annual network infrastructure reviews

Essential Network Commands

💻 Windows Commands

ipconfig /all

Display all network adapter configurations

ipconfig /release && ipconfig /renew

Release and renew DHCP IP address

ipconfig /flushdns

Clear DNS resolver cache

netsh int ip reset

Reset TCP/IP stack to defaults

🍎 macOS Commands

ifconfig

Display network interface configurations

sudo dhclient -r && sudo dhclient

Release and renew DHCP lease

sudo dscacheutil -flushcache

Flush DNS cache

networksetup -listallhardwareports

List all network interfaces

🐧 Linux Commands

ip addr show

Display all network interfaces and IPs

sudo systemctl restart networking

Restart network services

sudo systemd-resolve --flush-caches

Clear DNS cache (systemd)

nmcli connection show

List network connections (NetworkManager)

When to Contact Support

🆘 ISP-Related Issues

  • Public IP address frequently changes unexpectedly
  • Location shows incorrect city/country consistently
  • Internet speed significantly slower than plan
  • Complete loss of internet connectivity

Contact: Your Internet Service Provider

🔧 Hardware Problems

  • Network adapter not detected by system
  • Router not responding to configuration changes
  • Physical connection issues (cables, ports)
  • Intermittent hardware failures

Contact: Hardware manufacturer or IT support

🏢 Corporate Network Issues

  • Cannot access company resources remotely
  • VPN connection fails repeatedly
  • Network policies blocking legitimate traffic
  • Security software interfering with connectivity

Contact: Your company's IT department

Start Network Troubleshooting Today

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