NETWORK
Default gatewayThe router that handles traffic leaving your subnet
The default gateway is the router address a device sends packets to when the destination is outside its own subnet. On a home network it is the router, typically 192.168.1.1 or 192.168.0.1. A device with no working gateway can talk to its local network but not to the internet.
What the gateway does
A host makes a simple decision for every outbound packet. It applies its subnet mask to the destination:
- Same subnet → find the destination's MAC address with ARP and send directly.
- Different subnet → send the packet to the default gateway's MAC address, leaving the IP destination unchanged. The router then forwards it toward its destination.
In the routing table this appears as the route 0.0.0.0 with mask 0.0.0.0 (or 0.0.0.0/0): "everything not matched by a more specific route". The route record shows how to read the table.
Where it comes from
DHCP supplies the gateway (option 3, "Router") along with the address and mask. On a static configuration you enter it yourself, and it must be an address on the same subnet as the host. A gateway of 192.168.1.1 with a host of 192.168.2.10/24 will never work because the host cannot ARP for an address outside its subnet.
Home networks
The gateway is the router's LAN address, most often 192.168.1.1, 192.168.0.1, 10.0.0.1 or 192.168.1.254, and the same address usually serves the router's admin page and DNS forwarding. The router performs NAT as traffic leaves toward the ISP.
Larger networks
Each VLAN or subnet has its own gateway, usually an interface on a layer-3 switch or firewall. First-hop redundancy protocols (VRRP, HSRP) let two routers share one gateway address so that the failure of one does not strand the subnet.
Finding and testing it on Windows
ipconfig
ping 192.168.1.1
tracert 1.1.1.1ipconfig shows the gateway; ping confirms it answers; tracert should show the gateway as the first hop. If the first hop times out, the problem is between the PC and the router (cable, Wi-Fi, driver, wrong address). If the first hop answers but later hops fail, the problem is upstream. See ping and tracert.
Common faults
| Symptom | Cause |
|---|---|
Gateway blank in ipconfig | DHCP failed (169.254.x.x address) or static config incomplete |
| Gateway set but unreachable | Router down, wrong subnet, Wi-Fi power saving, VLAN mismatch |
| Local network works, internet does not | Gateway fine, but router's WAN link or DNS is broken |
| "Default gateway is not available" repeatedly on Wi-Fi | Adapter driver or power-management setting; update the driver and disable "allow the computer to turn off this device" |
Frequently asked questions
How do I find my default gateway?
On Windows, run ipconfig and read the Default Gateway line under the active adapter. On macOS and Linux, netstat -rn or ip route shows it as the default route. It is usually the router's LAN address.
What does "The default gateway is not available" mean?
The Windows network troubleshooter reports this when the PC cannot reach the gateway address by ARP. Causes include a Wi-Fi driver or power-management problem, a router that has crashed or rebooted, a wrong static gateway, or a DHCP lease from a router that has since changed address.
Can a device have two default gateways?
Windows allows it but only uses one at a time (the lowest metric), and having two on different adapters causes confusing behaviour. One gateway per device is the rule; multiple paths are handled by routing protocols on routers, not on hosts.