connman.conf(5) File Formats Manual connman.conf(5)

main.conf - ConnMan configuration file


main.conf is a configuration file for ConnMan. The configuration file is optional but it can be used to set up various aspects of ConnMan's behavior. The location of the file may be changed through use of the --config= argument for connman(8).

The configuration file consists of sections (groups) of key-value pairs. Lines beginning with a '#' and blank lines are considered comments. Sections are started by a header line containing the section enclosed in '[' and ']', and ended implicitly by the start of the next section or the end of the file. Each key-value pair must be contained in a section.

Description of sections and available keys follows:

This section is the only mandatory section of the configuration file.
Set input request timeout. Default is 120 seconds The request for inputs like passphrase will timeout after certain amount of time. Use this setting to increase the value in case of different user interface designs.
Set browser launch timeout. Default is 300 seconds The request for launching a browser for portal pages will timeout after certain amount of time. Use this setting to increase the value in case of different user interface designs.
BackgroundScanning=true | false
Enable background scanning. Default is true. If wifi is disconnected, the background scanning will follow a simple backoff mechanism from 3s up to 5 minutes. Then, it will stay in 5 minutes unless user specifically asks for scanning through a D-Bus call. If so, the mechanism will start again from 3s. This feature activates also the background scanning while being connected, which is required for roaming on wifi. When BackgroundScanning is false, ConnMan will not perform any scan regardless of wifi is connected or not, unless it is requested by the user through a D-Bus call.
UseGatewaysAsTimeservers=true| false
Assume that service gateways also function as timeservers. Default is false.
List of Fallback timeservers separated by ",". These timeservers are used for NTP sync when there are no timeservers set by the user or by the service, and when UseGatewaysAsTimeservers = false. These can contain a mixed combination of fully qualified domain names, IPv4 and IPv6 addresses.
List of fallback nameservers separated by "," appended to the list of nameservers given by the service. The nameserver entries must be in numeric format, host names are ignored.
List of technologies that are marked autoconnectable by default, separated by commas ",". The default value for this entry when empty is ethernet,wifi,cellular. Services that are automatically connected must have been set up and saved to storage beforehand.
List of technologies that are marked favorite by default, separated by commas ",". The default value for this entry when empty is ethernet. Connects to services from this technology even if not setup and saved to storage.
List of technoolgies which are always connected regardless of PreferredTechnologies setting (AutoConnect = true). The default value is empty and this feature is disabled unless explicitly enabled in the config file.
List of preferred technologies from the most preferred one to the least preferred one separated by commas ",". Services of the listed technology type will be tried one by one in the order given, until one of them gets connected or they are all tried. A service of a preferred technology type in state 'ready' will get the default route when compared to another preferred type further down the list with state 'ready' or with a non-preferred type; a service of a preferred technology type in state 'online' will get the default route when compared to either a non-preferred type or a preferred type further down in the list.
List of blacklisted network interfaces separated by ",". Found interfaces will be compared to the list and will not be handled by connman, if their first characters match any of the list entries. Default value is vmnet,vboxnet,virbr,ifb.
AllowHostnameUpdates=true | false
Allow connman to change the system hostname. This can happen for example if we receive DHCP hostname option. Default value is true.
AllowDomainnameUpdates=true | false
Allow connman to change the system domainname. This can happen for example if we receive DHCP domainname option. Default value is true.
SingleConnectedTechnology=true | false
Keep only a single connected technology at any time. When a new service is connected by the user or a better one is found according to PreferredTechnologies, the new service is kept connected and all the other previously connected services are disconnected. With this setting it does not matter whether the previously connected services are in 'online' or 'ready' states, the newly connected service is the only one that will be kept connected. A service connected by the user will be used until going out of network coverage. With this setting enabled applications will notice more network breaks than normal. Default value is false.
List of technologies that are allowed to enable tethering separated by ",". The default value is wifi,bluetooth,gadget. Only those technologies listed here are used for tethering. If one wants to tether ethernet, then add "ethernet" in the list. NOTE that if ethernet tethering is enabled, then a DHCP server is started on all ethernet interfaces. Tethered ethernet should never be connected to corporate or home network as it will disrupt normal operation of these networks. Due to this ethernet is not tethered by default. Do not activate ethernet tethering unless you really know what you are doing.
PersistentTetheringMode=true | false
Restore earlier tethering status when returning from offline mode, re-enabling a technology, and after restarts and reboots. Default value is false.
Enable6to4=true | false
Automatically enable Anycast 6to4 if possible. This is not recommended, as the use of 6to4 will generally lead to a severe degradation of connection quality. See RFC6343. Default value is false (as recommended by RFC6343 section 4.1).
Set DHCP option 60 (Vendor Class ID) to the given string. This option can be used by DHCP servers to identify specific clients without having to rely on MAC address ranges, etc
EnableOnlineCheck=true | false
Enable or disable use of HTTP GET as an online status check. When a service is in a READY state, and is selected as default, ConnMan will issue an HTTP GET request to verify that end-to-end connectivity is successful. Only then the service will be transitioned to ONLINE state. If this setting is false, the default service will remain in READY state. Default value is true.
Range of intervals between two online check requests. When an online check request fails, another one is triggered after a longer interval. The intervals follow the power of two series of numbers between OnlineCheckInitialInterval and OnlineCheckMaxInterval. Default range is [1, 12], corresponding to the following intervals, in seconds: 1, 4, 9, 16, 25, 36, 49, 64, 81, 100, 121 and 144.
EnableOnlineToReadyTransition=true | false
WARNING: Experimental feature!!! In addition to EnableOnlineCheck setting, enable or disable use of HTTP GET to detect the loss of end-to-end connectivity. If this setting is false, when the default service transitions to ONLINE state, the HTTP GET request is no more called until next cycle, initiated by a transition of the default service to DISCONNECT state. If this setting is true, the HTTP GET request keeps beeing called to guarantee that end-to-end connectivity is still successful. If not, the default service will transition to READY state, enabling another service to become the default one, in replacement. Default value is false.
AutoConnectRoamingServices=true | false
Automatically connect roaming services. This is not recommended unless you know you won't have any billing problem. Default value is false.
AddressConflictDetection=true | false
Enable or disable the implementation of IPv4 address conflict detection according to RFC5227. ConnMan will send probe ARP packets to see if an IPv4 address is already in use before assigning the address to an interface. If an address conflict occurs for a statically configured address, an IPv4LL address will be chosen instead (according to RFC3927). If an address conflict occurs for an address offered via DHCP, ConnMan send a DHCP DECLINE once and for the second conflict resort to finding an IPv4LL address. Default value is false.

The following example configuration disables hostname updates and enables ethernet tethering.
AllowHostnameUpdates = false
AllowDomainnameUpdates = false
TetheringTechnologies = ethernet,wifi,bluetooth,gadget