RBMTX-Viper DHCP and DNS
Z Elproma Wiki Knowledge Base
The DHCP and DNS page of RBMTX-Lite router is used to manage DHCP-Server and DNS-Forwarder for NAT firewalls.
Server Settings
General Settings
| Name | Value | Description |
|---|---|---|
| Domain required | On/Off, default: On | Don't forward DNS-Requests without DNS-Name |
| Authoritative | On/Off, default: On | This is the only DHCP-Server in the local network |
| Local server | path, default: /lan/ | Local domain specification. Names matching this domain are never forwarded and are resolved from DHCP or hosts files only |
| Local domain | string, default: lan | Local domain suffix appended to DHCP names and hosts file entries |
| Log queries | On/Off, default: Off | Write received DNS requests to syslog |
| DNS forwardings | List of DNS servers to forward requests to | |
| Addresses | List of domains to force to an IP address. | |
| Rebind protection | On/Off, default: On | Discard upstream RFC1918 responses |
| Allow localhost | On/Off, default: On | Allow upstream responses in the 127.0.0.0/8 range, e.g. for RBL services |
| Domain whitelist | List of domains to allow RFC1918 responses for | |
| Local Service Only | On/Off, default: On | Limit DNS service to subnets interfaces on which we are serving DNS. |
| Non-wildcard | On/Off, default: On | Bind dynamically to interfaces rather than wildcard address (recommended as linux default) |
| Listen Interfaces | Limit listening to these interfaces, and loopback. | |
| Exclude interfaces | Prevent listening on these interfaces. |
Resolv and Hosts Files
| Name | Value | Description |
|---|---|---|
| Use /etc/ethers | On/Off, default: On | Read /etc/ethers to configure the DHCP-Server |
| Leasefile | path, default: /tmp/dhcp.leases | file where given DHCP-leases will be stored |
| Ignore resolve file | On/Off, default: Off | |
| Resolve file | path, default: /tmp/resolv.conf.d/resolv.conf.auto | local DNS file |
| Ignore /etc/hosts | On/Off, default: Off | |
| Additional Hosts files |
TFTP Settings
| Name | Value | Description |
|---|---|---|
| Enable TFTP server | On/Off, default: Off | |
| TFTP server root | path | Root directory for files served via TFTP |
| Network boot image | string | Filename of the boot image advertised to clients |
Advanced Settings
| Name | Value | Description |
|---|---|---|
| Suppress logging | On/Off, default: Off | Suppress logging of the routine operation of these protocols |
| Allocate IP sequentially | On/Off, default: Off | Allocate IP addresses sequentially, starting from the lowest available address |
| Filter private | On/Off, default: On | Do not forward reverse lookups for local networks |
| Filter useless | On/Off, default: Off | Do not forward requests that cannot be answered by public name servers |
| Localise queries | On/Off, default: On | Localise hostname depending on the requesting subnet if multiple IPs are available |
| Expand hosts | On/Off, default: Off | Add local domain suffix to names served from hosts files |
| No negative cache | On/Off, default: Off | Do not cache negative replies, e.g. for not existing domains |
| Additional servers file | This file may contain lines like 'server=/domain/1.2.3.4' or 'server=1.2.3.4' for domain-specific or full upstream DNS servers. | |
| Strict order | On/Off, default: Off | DNS servers will be queried in the order of the resolvfile |
| All Servers | On/Off, default: Off | Query all available upstream DNS servers |
| Bogus NX Domain Override | List of hosts that supply bogus NX domain results | |
| DNS server port | number, from 0 to 65535 | Listening port for inbound DNS queries |
| DNS query port | number, from 0 to 65535 | Fixed source port for outbound DNS queries |
| Max. DHCP leases | number | Maximum allowed number of active DHCP leases |
| Max. EDNS0 packet size | number, default: 1232 | Maximum allowed size of EDNS.0 UDP packets |
| Max. concurrent queries | number | Maximum allowed number of concurrent DNS queries |
| Size of DNS query cache | number from 0 to 10000 | Number of cached DNS entries (0 is no caching) |
Static Leases
Static leases are used to assign fixed IP addresses and symbolic hostnames to DHCP clients. They are also required for non-dynamic interface configurations where only hosts with a corresponding lease are served.
Use the Add Button to add a new lease entry. The MAC address identifies the host, the IPv4 address specifies the fixed address to use, and the Hostname is assigned as a symbolic name to the requesting host. The optional Lease time can be used to set non-standard host-specific lease time, e.g. 12h, 3d or infinite.
