The DHCP section configuresDocumentation Index
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dnsmasq, the combined DHCP server and DNS forwarder that runs on your OpenWrt router. It is split across five tabs covering general settings, file paths, TFTP, advanced DNS tuning, and static address assignments. A separate page manages host name entries.
All DHCP pages require an active session. If you are not logged in, the application redirects you to /login.
Changes on each tab are saved to the router’s UCI configuration via
dnsmasq. Click Save and Apply to write changes immediately, or Save to stage them without applying.Navigating between sections
Switch tabs
Use the tab bar at the top of the panel to move between: General configuration, Resolv and Hosts files, TFTP configuration, Advanced configuration, and Static assignments.
General configuration — /dhcp
This tab configures the core behavior of the dnsmasq process.
| Setting | Description |
|---|---|
| Require domain | Do not forward DNS queries that have no domain component |
| Authoritative | Declare this as the only DHCP server on the LAN |
| Local server | Domain specification (e.g. /lan/) — matching queries are resolved locally and never forwarded |
| Local domain | Domain suffix appended to DHCP client hostnames (e.g. lan) |
| Log queries | Write all received DNS queries to the system log |
| DNS forwarding | List of upstream DNS servers per domain (/example.org/10.1.2.3) |
| Rebind protection | Discard RFC 1918 responses from upstream DNS servers |
| Allow localhost | Allow upstream responses in the 127.0.0.0/8 range |
| Domain whitelist | Domains exempt from rebind protection (e.g. ihost.netflix.com) |
| Local service only | Restrict DNS service to subnets directly attached to the router’s interfaces |
| No wildcard | Bind only to specific interface addresses rather than the wildcard address 0.0.0.0 |
| Listen interfaces | Explicit list of interfaces on which dnsmasq listens |
| Exclude interfaces | Interfaces excluded from dnsmasq even if they match other criteria |
Resolv and Hosts files — /dhcp/resolv
This tab controls which files dnsmasq reads for DNS resolution and how lease data is stored.
| Setting | Description |
|---|---|
Use /etc/ethers | Read /etc/ethers to populate DHCP static assignments |
| Lease file | Path to the active DHCP leases file (default: /tmp/dhcp.leases) |
| Ignore resolv file | Do not read the resolv file for upstream DNS servers |
| Resolv file | Path to the resolv file (default: /tmp/resolv.conf.auto) |
Ignore /etc/hosts | Do not use the system hosts file for local name resolution |
| Additional host files | Extra hosts files to include alongside /etc/hosts |
TFTP configuration — /dhcp/tftp
The TFTP tab enables the built-in TFTP server inside dnsmasq, which is used for PXE network booting.
| Setting | Description |
|---|---|
| Enable TFTP server | Toggle to activate the TFTP boot service |
Static assignments — /dhcp/estaticas
Static assignments bind a specific MAC address to a fixed IP address so that a device always receives the same address from DHCP.
Each static assignment contains:
| Field | Description |
|---|---|
| Hostname | Symbolic name for the host |
| MAC address | Hardware address that identifies the device |
| IPv4 address | Fixed address the router will always assign to this MAC |
| Lease time | Optional non-default lease duration (e.g. 12h, 3d, infinite) |
| DUID | DHCPv6 unique identifier for IPv6 static assignments |
| IPv6 suffix (hex) | Suffix appended to the prefix for the IPv6 address |
Advanced configuration — /dhcp/avanzada
The advanced tab exposes DNS tuning options that control filtering, caching, and forwarding behavior.
| Setting | Description |
|---|---|
| Filter requests | Suppress logging of common, routine DNS queries |
| Sequential IP allocation | Assign addresses starting from the lowest available address instead of randomly |
| Private filter | Do not forward reverse DNS queries for RFC 1918 addresses |
| Local filter | Do not forward queries that public DNS servers cannot answer |
| Localize queries | Route queries to the closest name server by interface |
| Expand hosts | Append the local domain suffix to bare hostnames read from the hosts file |
| No negative cache | Disable caching of negative (NXDOMAIN) responses |
| Additional servers file | Path to a supplementary dnsmasq configuration file |
| No duplicate hosts | Prevent a local host from using a name already in the hosts file |
| All servers | Query all upstream DNS servers simultaneously and use the fastest response |
| DNS server port | Port dnsmasq listens on (default: 53) |
| DNS query port | Source port used for outbound DNS queries |
| Max DHCP leases | Maximum number of concurrent active DHCP assignments (default: 150) |
| Max concurrent DNS queries | Maximum simultaneous in-flight DNS queries (default: 150) |
| DNS cache size | Number of DNS responses to cache in memory (default: 150) |
Host names — /nombres-host
The host names page (/nombres-host) manages entries in the router’s local DNS. Each entry maps a hostname to a specific IP address, making it resolvable by all devices on the network without an external DNS server.