Static IP fails because the address/subnet mask/gateway/ DNS is not that of your network, or the address is within the router's DHCP pool. Resolve it by selecting an unused address that is outside that pool and is within your subnet, has the same gateway and subnet, and points DNS to reachable servers. Save, disable & enable, and test using ping.
Symptoms
- Device shows "Limited" or "No internet" after switching from DHCP to manual settings
- Local resources reachable but public sites fail to load, or vice versa
- Duplicate IP warning appears on Windows, or another device suddenly loses connectivity
- ping to the default gateway times out or returns "Destination host unreachable"
- nslookup fails while direct IP addresses still respond to ping
Common Causes
Address inside the DHCP pool
The router later hands the same address to another client, triggering a duplicate-IP conflict. Static assignments must sit outside the DHCP range or be reserved on the router.
Subnet mask does not match the LAN
A /24 host on a /23 network, or a typo like 255.255.255.192, isolates the device. It can talk to a subset of hosts but never reaches the gateway.
Wrong or unreachable default gateway
If the gateway is on a different subnet or points to an offline device, all off-LAN traffic drops. The router silently ignores frames it never receives.
Missing or invalid DNS servers
Manual configuration replaces DHCP-supplied DNS with blanks or a stale entry. Browsing appears broken while ping by IP still works.
VLAN, MAC filter, or firewall block
Managed switches, MAC allow-lists, and endpoint firewalls can drop a manually assigned address that was never authorised for the port or SSID.
Step-by-Step Fix
- Take the original network info from your route-
Log in to the admin interface of your router and write down the LAN subnet, mask, gateway, and DHCP pool boundaries. Also write down the DNS servers it hands out, they're needed for any manual setup. - Select a free address outside the DHCP scope:
If they give you 100 to.200, select something smaller (e.g., .10) or larger (e.g., .240). Ping it from another machine; run arp -a. If there is no reply, the address should be free. - Use static config on client -
On Windows, open Network Connections, right-click the adapter, Properties, IPv4, Properties, then select Use the following IP address. On macOS, select System Settings, Network, Details, TCP/IP, then Configure IPv4: Manually. On Linux, edit the Netplan or Network Manager profile and enter an IP, mask, gateway, and 2 DNS servers. - Bounce the interface and flush caches:
Turning the adapter off then on, or running ipconfig /release then ipconfig /renew, is not required for static, but ipconfig /flushdns and arp -d * (elevated) should be performed to clear out stale entries. On macOS, turn Wi-Fi on, then off, or unplug Ethernet briefly. - Check layer 3 connectivity in order to:
Ping 127.0.0.1, then your static IP, then your gateway, then a public IP (like 1.1.1.1), then a hostname (like technow.com). Fail at the first step, and you will see the point at which the network is broken. - Reserve the address on the router (recommended):
Set the device's MAC to the chosen IP in the router's DHCP reservation table. You get the foresight of a static IP without the dangers of conflict when someone screws up the LAN scheme later. - Verify no switch, VLAN, firewall blocks:
If all the previous steps seem fine and the host is still being isolated then verify the switch port's VLAN, and any MAC allow-list configured on the AP or router. Disable the local firewall to see if it silently drops ARP or ICMP.
Common static IP symptoms mapped to likely cause and fix
| Symptom | Likely cause | Fix |
|---|---|---|
| "IP address conflict" toast on Windows | Address is inside the DHCP pool | Move IP outside the pool or add a DHCP reservation |
| Ping to gateway fails | Wrong subnet mask or gateway typo | Re-enter mask and gateway from the router's LAN page |
| Websites fail, ping by IP works | Missing or wrong DNS | Set DNS to the router or a public resolver such as 1.1.1.1 |
| Reaches LAN but not the internet | Gateway points to a non-router device | Correct the default gateway to the router's LAN address |
| No traffic at all after saving | Port on managed switch is in the wrong VLAN | Move port to the correct VLAN or check the trunk config |
| Works, then drops after hours | Duplicate MAC or overlapping reservation | Audit reservations and remove duplicates |
Prevention
- Document the LAN scheme: subnet, mask, gateway, DHCP range, and reserved addresses.
- Prefer DHCP reservations over pure static assignments for printers, NAS, and cameras.
- Keep at least ten addresses outside the DHCP pool for infrastructure and lab use.
- Label devices with their assigned IP so a swap or reset does not break the plan.
FAQ
Is a static IP preferable to a DHCP reservation?
For most devices, yes. As the router governs the IP addressing scheme, it will always give the same IP to the same MAC, so static behavior without client hassle is ensured. Reserve for printers, NAS, cameras, and servers. Use pure static only if the device is expected to work before the DHCP server is online.
What DNS should I use?
Begin with your router's LAN address so that local name resolution still functions. As a backup, use a dependable public resolver like 1.1.1.1 or 9.9.9.9. If the device is part of a Windows domain, direct DNS to the domain controllers. Do not leave both DNS slots empty for manual setup.
Why am I able to access it on my local network but not via the Internet even with static IP address?
Nearly always a gateway or DNS problem. Ping the router's LAN IP; if that works, ping 1.1.1.1. If the public ping works but browsing doesn't, the DNS is wrong. If the public ping doesn't work, the default gateway is wrong, or the router blocks the unknown host at the firewall.