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Applies to RouterOS: v4.6

DNS cache is used to minimize DNS requests to an external DNS server as well as to minimize DNS resolution time. This is a simple DNS cache with local items.


  • Packages required: system
  • License required: Level1
  • Submenu level: /ip dns
  • Standards and Technologies: DNS
  • Hardware usage: Not significant


A MikroTik router with DNS feature enabled can be set as a DNS server for any DNS-compliant client. Moreover, MikroTik router can be specified as a primary DNS server under its dhcp-server settings. When the remote requests are enabled, the MikroTik router responds to TCP and UDP DNS requests on port 53.

DNS Cache Setup

Sub-menu: /ip dns

DNS facility is used to provide domain name resolution for router itself as well as for the clients connected to it.


Property Description
allow-remote-requests (yes | no; Default: no) Specifies whether to allow network requests
cache-max-ttl (time; Default: 1w) Maximum time-to-live for cache records. In other words, cache records will expire unconditionally after cache-max-ttl time. Shorter TTL received from DNS servers are respected.
cache-size (integer[64..4294967295]; Default: 2048) Specifies the size of DNS cache in KiB
max-concurrent-queries (integer; Default: 100) Specifies how much concurrent queries are allowed
max-concurrent-tcp-sessions (integer; Default: 20) Specifies how much concurrent TCP sessions are allowed
max-udp-packet-size (integer [50..65507]; Default: 4096) Maximum size of allowed UDP packet.
query-server-timeout (time; Default: 2s) Specifies how long to wait for query response from one server
query-total-timeout (time; Default: 10s) Specifies how long to wait for query response in total. Note that this setting must be configured taking into account query-server-timeout and number of used DNS server.
servers (list of IPv4/IPv6 addresses; Default: ) List of DNS server IPv4/IPv6 addresses

Read-only Properties

Property Description
cache-used (integer) Shows the currently used cache size in KiB
dynamic-server (IPv4/IPv6 list) List of dynamically added DNS server from different services, for example, DHCP.

When both static and dynamic servers are set, static server entries are more preferred, however it does not indicate that static server will always be used (for example, previously query was received from dynamic server, but static was added later, then dynamic entry will be preferred).


Note: If allow-remote-requests is used make sure that you limit access to your server over TCP and UDP protocol.


To set as the primary DNS server and allow the router to be used as a DNS server, do the following:

[admin@MikroTik] ip dns> set servers= \
\... allow-remote-requests=yes
[admin@MikroTik] ip dns> print
  allow-remote-requests: yes
             cache-size: 2048KiB
          cache-max-ttl: 1w
             cache-used: 7KiB
[admin@MikroTik] ip dns>

Cache Monitoring

  • Submenu level: /ip dns cache


This menu provides a list with all address (DNS type "A") records stored on the server

Property Description

Property Desciption
address (read-only: IP address) IP address of the host
name (read-only: name) DNS name of the host
ttl (read-only: time) remaining time-to-live for the record

All DNS Entries

  • Submenu level: /ip dns cache all


This menu provides a complete list with all DNS records stored on the server

Property Description

Property Desciption
data (read-only: text) DNS data field. IP address for type "A" records. Other record types may have different contents of the data field (like hostname or arbitrary text)
name (read-only: name) DNS name of the host
ttl (read-only: time) remaining time-to-live for the record
type (read-only: text) DNS record type

Static DNS Entries

  • Submenu level: /ip dns static


The MikroTik RouterOS has an embedded DNS server feature in DNS cache. It allows you to link the particular domain names with the respective IP addresses and advertize these links to the DNS clients using the router as their DNS server. This feature can also be used to provide fake DNS information to your network clients. For example, resolving any DNS request for a certain set of domains (or for the whole Internet) to your own page.

The server is capable of resolving DNS requests based on POSIX basic regular expressions, so that multiple requets can be matched with the same entry. In case an entry does not conform with DNS naming standards, it is considered a regular expression and marked with ‘R’ flag. The list is ordered and is checked from top to bottom. Regular expressions are checked first, then the plain records.

Property Description

Property Desciption
address (IP address) IP address to resolve domain name with
name (text) DNS name to be resolved to a given IP address.
regex (text) DNS regex
ttl (time) time-to-live of the DNS record


Reverse DNS lookup (Address to Name) of the regular expression entries is not possible. You can, however, add an additional plain record with the same IP address and specify some name for it.

Remember that the meaning of a dot (.) in regular expressions is any character, so the expression should be escaped properly. For example, if you need to match anything within domain but not all the domains that just end with, like, use name=".*\\.example\\.com"

Regular expression matching is significantly slower than of the plain entries, so it is advised to minimize the number of regular expression rules and optimize the expressions themselves. Example

To add a static DNS entry for to be resolved to IP address:

[admin@MikroTik] ip dns static> add address=
[admin@MikroTik] ip dns static> print
Flags: D - dynamic, X - disabled, R - regexp
 #     NAME               ADDRESS                                 TTL
 0                                1d
[admin@MikroTik] ip dns static>

Or use regex to match DNS requests:

[admin@MikroTik] ip dns static> add regexp="[*example*]" address=

For more information how to use regex, read wiki page below.

Flushing DNS cache

  • Command name: /ip dns cache flush

Command Description

Command Desciption
flush clears internal DNS cache


[admin@MikroTik] ip dns> cache flush
[admin@MikroTik] ip dns> print
    allow-remote-requests: yes
               cache-size: 2048 KiB
            cache-max-ttl: 1w
               cache-used: 10 KiB
[admin@MikroTik] ip dns>

See Also