So, you can easily install it using the APT package manager. Before you install dnsmasq, you must stop and disable systemd-resolved services. In order to configure dnsmasq as a DNS server, you have to modify this file.
Now, you have to set Now, type in nameserver Then save the file. You can add as many DNS entries as you want. Assuming the packages are installed, use drill utility to verify DNS caching;. That marks the end of our tutorial on how to install and configure local DNS server using Dnsmasq on Ubuntu Have you tried this recently?
Save my name, email, and website in this browser for the next time I comment. Buy Me a Coffee. Saturday, November 13, Sign in. Forgot your password? Get help. Password recovery. Note that if no subnets are specified, then no reverse queries are answered. Note that this is optional, all the values are set to sane defaults. These servers must be configured to get zone data from dnsmasq by zone transfer, and answer queries for the same authoritative zones as dnsmasq.
If this option is not given, then AXFR requests will be accepted from any secondary. This allows traffic generated by dnsmasq to be associated with the queries which cause it, useful for bandwidth accounting and firewalling.
Dnsmasq must have conntrack support compiled in and the kernel must have conntrack support included and configured. This option cannot be combined with --query-port. If the lease time is given, then leases will be given for that length of time. The lease time is in seconds, or minutes eg 45m or hours eg 1h or "infinite".
If not given, the default lease time is one hour. The minimum lease time is two minutes. For IPv6 ranges, the lease time maybe "deprecated"; this sets the preferred lifetime sent in a DHCP lease or router advertisement to zero, which causes clients to use other addresses, if available, for new connections as a prelude to renumbering.
This option may be repeated, with different addresses, to enable DHCP service to more than one network. For directly connected networks ie, networks on which the machine running dnsmasq has an interface the netmask is optional: dnsmasq will determine it from the interface configuration. For networks which receive DHCP service via a relay agent, dnsmasq cannot determine the netmask itself, so it should be specified, otherwise dnsmasq will have to guess, based on the class A, B or C of the network address.
The broadcast address is always optional. It is always allowed to have more than one dhcp-range in a single subnet. For IPv6, the parameters are slightly different: instead of netmask and broadcast address, there is an optional prefix length which must be equal to or larger then the prefix length on the local interface.
If not given, this defaults to Unlike the IPv4 case, the prefix length is not automatically derived from the interface configuration. The minimum size of the prefix length is IPv6 only supports another type of range. This forms a template which describes how to create ranges, based on the addresses assigned to the interface. If the interface is assigned more than one network, then the corresponding ranges will be automatically created, and then deprecated and finally removed again as the address is deprecated and then deleted.
Note that just any address on eth0 will not do: it must not be an autoconfigured or privacy address, or be deprecated. When it is prefixed with 'tag:' instead, then its meaning changes from setting a tag to matching it. Only one tag may be set, but more than one tag may be matched. See pxe-prompt and pxe-service for details. For IPv6, the mode may be some combination of ra-only, slaac, ra-names, ra- stateless, ra-advrouter, off-link.
Note that this is only happens for directly-connected networks, not one doing DHCP via a relay and it will not work if a host is using privacy extensions.
This is described in RFC section 7. In this mode the interval option is also included, as described in RFC section 7. This allows a machine with a particular hardware address to be always allocated the same hostname, IP address and lease time.
A hostname specified like this overrides any supplied by the DHCP client on the machine. It is also allowable to omit the hardware address and include the hostname, in which case the IP address and lease times will apply to any machine claiming that name. Addresses allocated like this are not constrained to be in the range given by the --dhcp-range option, but they must be in the same subnet as some valid dhcp-range.
For subnets which don't need a pool of dynamically allocated addresses, use the "static" keyword in the dhcp-range declaration. It is allowed to use client identifiers called client DUID in IPv6-land rather than hardware addresses to identify hosts by prefixing with 'id:'.
A single dhcp-host may contain an IPv4 address or an IPv6 address, or both. See --cname. The special keyword "ignore" tells dnsmasq to never offer a DHCP lease to a machine.
This can be used to selectively send DHCP options just for this host. As a special case, in DHCPv4, it is possible to include more than one hardware address. Beware that this is a dangerous thing to do, it will only work reliably if only one of the hardware addresses is active at any time and there is no way for dnsmasq to enforce this. It is, for instance, useful to allocate a stable IP address to a laptop which has both wired and wireless interfaces.
The file contains information about one host per line. The advantage of using this option is the same as for --dhcp-hostsfile: the dhcp-optsfile will be re-read when dnsmasq receives SIGHUP. Note that it is possible to encode the information in a --dhcp-boot flag as DHCP options, using the options names bootfile-name, server-ip- address and tftp-server.
This allows these to be included in a dhcp-optsfile. The path MUST be a directory, and not an individual file. If a file is deleted or changed after it has been read by dnsmasq, then the host record it contained will remain until dnsmasq receives a SIGHUP, or is restarted; ie host records are only added dynamically. When read by dnsmasq these lines have exactly the same effect as --dhcp- host options containing the same information.
By default, dnsmasq sends some standard options to DHCP clients, the netmask and broadcast address are set to the same as the host running dnsmasq, and the DNS server and default route are set to the address of the machine running dnsmasq. Equivalent rules apply for IPv6.
If the domain name option has been set, that is sent. This configuration allows these defaults to be overridden, or other options specified. The set of option-names known by dnsmasq can be discovered by running "dnsmasq --help dhcp".
For example, to set the default route option to Data types allowed are comma separated dotted-quad IPv4 addresses, []-wrapped IPv6 addresses, a decimal number, colon-separated hex digits and a text string. If the optional tags are given then this option is only sent when all the tags are matched. Special processing is done on a text argument for option , to conform with RFC Dotted-quad IP addresses which are followed by a slash and then a netmask size are encoded as described in RFC IPv6 options are specified using the option6: keyword, followed by the option number or option name.
The IPv6 option name space is disjoint from the IPv4 option name space. IPv6 addresses in options must be bracketed with square brackets, eg. Be careful: no checking is done that the correct type of data for the option number is sent, it is quite possible to persuade dnsmasq to generate illegal DHCP packets with injudicious use of this flag. When the value is a decimal number, dnsmasq must determine how large the data item is. This is mainly useful with encapsulated vendor class options see below where dnsmasq cannot determine data size from the option number.
Option data which consists solely of periods and digits will be interpreted by dnsmasq as an IP address, and inserted into an option as such. To force a literal string, use quotes. The vendor-class matching is substring based see --dhcp-vendorclass for details. If a vendor-class option number 60 is sent by dnsmasq, then that is used for selecting encapsulated options in preference to any sent by the client. If multiple options are given which are encapsulated with the same option number then they will be correctly combined into one encapsulated option.
This form of encapsulation is supported in IPv6. The address 0. This is sometimes needed, for example when sending options to PXELinux. If it can, dnsmasq moves the boot server and filename information from dhcp-boot out of their dedicated fields into DHCP options. This make extra space available in the DHCP packet for options but can, rarely, confuse old or broken clients.
This flag forces "simple and safe" behaviour to avoid problems in such a case. The local address is an address allocated to an interface on the host running dnsmasq. It is possible to relay from a single local address to multiple remote servers by using multiple dhcp-relay configs with the same local address and different server addresses. A server address must be an IP literal address, not a domain name.
In this case the interface must be given, not be wildcard, and is used to direct the multicast to the correct interface to reach the DHCP server. The optional interface name in the dhcp-relay config has a different function: it controls on which interface DHCP replies from the server will be accepted.
This is intended for configurations which have three interfaces: one being relayed from, a second connecting the DHCP server, and a third untrusted network, typically the wider internet. It avoids the possibility of spoof replies arriving via this third interface.
It is allowed to have dnsmasq act as a DHCP server on one set of interfaces and relay from a disjoint set of interfaces. Note that whilst it is quite possible to write configurations which appear to act as a server and a relay on the same interface, this is not supported: the relay function will take precedence.
Most DHCP clients provide a "vendor class" which represents, in some sense, the type of host. This option maps vendor classes to tags, so that DHCP options may be selectively delivered to different classes of hosts.
The set: prefix is optional but allowed for consistency. This is given with enterprise: keyword and specifies that only vendorclasses matching the specified number should be searched. Most DHCP clients provide a "user class" which is configurable. This option maps user classes to tags, so that DHCP options may be selectively delivered to different classes of hosts. It is possible, for instance to use this to set a different printer server for hosts in the class "accounts" than for hosts in the class "engineering".
The MAC address may include wildcards. This data may be provided by DHCP relay agents. The circuit-id or remote-id is normally given as colon-separated hex, but is also allowed to be a simple string. If an exact match is achieved between the circuit or agent ID and one provided by a relay agent, the tag is set. Once a client is configured, it communicates directly with the server. This is undesirable if the relay agent is adding extra information to the DHCP packets, such as that used by dhcp-circuitid and dhcp- remoteid.
A full relay implementation can use the RFC serverid-override option to force the DHCP server to use the relay as a full proxy, with all packets passing through it. This flag provides an alternative method of doing the same thing, for relays which don't support RFC Given alone, it manipulates the server-id for all interactions via relays. If a list of IP addresses is given, only interactions via relays at those addresses are affected.
When a value is given, set the tag only if the option is sent and matches the value. If the value is a string, substring matching is used. Please see RFC for more details of these rare and interesting beasts.
Any number of set: and tag: forms may appear, in any order. Note that if a host provides a name, it will be used by preference to this, unless --dhcp-ignore-names is set. It is permissible to supply no tags, in which case this is unconditional. Server name and address are optional: if not provided, the name is left empty, and the address set to the address of the machine running dnsmasq. If dnsmasq is providing a TFTP service see --enable-tftp then only the filename is required here to enable network booting.
If the optional tag s are given, they must match for this configuration to be sent. This facility can be used to load balance the tftp load among a set of servers. This normally allows a client's address to remain stable long-term, even if the client sometimes allows its DHCP lease to expire. In this default mode IP addresses are distributed pseudo-randomly over the entire available address range.
There are sometimes circumstances typically server deployment where it is more convenient to have IP addresses allocated sequentially, starting from the lowest available address, and setting this flag enables this mode. Note that in the sequential mode, clients which allow a lease to expire are much more likely to move IP address; for this reason it should not be generally used.
This specifies a boot option which may appear in a PXE boot menu. Note that the "layer" suffix normally ". Alternatively, the basename may be a filename, complete with suffix, in which case no layer suffix is added.
If an integer boot service type, rather than a basename is given, then the PXE client will search for a suitable boot service for that type on the network. If no boot service type or filename is provided or a boot service type of 0 is specified then the menu entry will abort the net boot procedure and continue booting from local media.
If the timeout is given then after the timeout has elapsed with no keyboard input, the first available menu option will be automatically executed. If the timeout is zero then the first available menu item will be executed immediately.
If pxe-prompt is omitted the system will wait for user input if there are multiple items in the menu, but boot immediately if there is only one. See pxe-service for details of menu items.
This mode is enabled using the proxy keyword in dhcp-range. The default is This limit is to prevent DoS attacks from hosts which create thousands of leases and use lots of memory in the dnsmasq process. This allows new hosts to get a lease without a tedious timeout under all circumstances. It also allows dnsmasq to rebuild its lease database without each client needing to reacquire a lease, if the database is lost.
For DHCPv6 it sets the priority in replies to the maximum instead of 0 the minimum. If this option is given alone, without arguments, it changes the ports used for DHCP from 67 and 68 to and If a single argument is given, that port number is used for the server and the port number plus one used for the client. Finally, two port numbers allows arbitrary specification of both server and client ports for DHCP. Use this with care, since each address allocated to a BOOTP client is leased forever, and therefore becomes permanently unavailable for re-use by other hosts.
With tags, only when the tags are all set. It may be repeated with different tag sets. It does this by sending an ICMP echo request aka "ping" to the address in question. If it gets a reply, then the address must already be in use, and another is tried.
This flag disables this check. Use with caution. Errors and problems will still be logged. This option is not normally required as dnsmasq creates a DUID automatically when it is first needed. The enterprise-id is assigned by IANA, and the uid is a string of hex octets unique to a particular device. If the MAC address is from a network type other than ethernet, it will have the network type prepended, eg "ab" for token ring.
The process is run as root assuming that dnsmasq was originally run as root even if dnsmasq is configured to change UID to an unprivileged user. Note that the hostname passed to the script as an argument is never fully-qualified. If the lease is a temporary allocation, this is prefixed to 'T'.
Note that the supplied hostname, vendorclass and userclass data is only supplied for "add" actions or "old" actions when a host resumes an existing lease, since these data are not held in dnsmasq's lease database. In debug mode, stdio, stdout and stderr file are left as those inherited from the invoker of dnsmasq.
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