For a minimal set of options to get dhcpy6d running see minimal settings.
Boolean settings can be done with 1/0, on/off or yes/no values.
The section [dhcpy6d] in the configuration file contains all general options. They will be discussed here.
Let dhcpy6d really_do_it and respond to client requests – might be of use for debugging and testing.
really_do_it = yes
The interfaces the server listens on is defined with keyword interface. Multiple interfaces have to be separated by spaces.
interface = eth0 eth1
The mcast address to listen at is ff02::1:2. Due to the facts that dhcpy6d at the moment works in local network segments only and to the restriction of MAC addresses only being usable there it will always have this value.
mcast = ff02::1:2
Exactly the same applies to the port dhcpy6d listens on. Probably senseless to change it but who knows.
port = 547
The server DUID should be configured with serverduid. If there is none dhcpy6d creates a new one at every startup. Windows clients might run a little bit wild when server DUID changed. You are free to compose your own as long as it follows RFC 3315. Please note that it has to be in hexadecimal format – no octals, no “-“, just like in the example below.
On Debian/Ubuntu systems when installed as package the DUID is noted in /etc/default/dhcpy6d.
The example here is a DUID-LLT (Link-layer Address Plus Time) even if it should be a DUID-TLL as timestamp comes first. It is composed of DUID-type(LLT=1) + Hardware-type(Ethernet=1) + Unixtime-in-hex + MAC-address what makes a 0001+0001+11fb5dc9+01023472a6c5 = 0001000111fb5dc901023472a6c5:
serverduid = 0001000111fb5dc901023472a6c5
The server_preference determines the priority of the server. Setups with failover capability might have use for it. The maximum value is 255 which means highest priority.
server_preference = 255
For security reasons dhcpy6d can be run as non-root user and group. Both IDs can be set with user and group:
user = dhcpy6d group = dhcpy6d
Nameservers to be replied to request option 23 are defined with nameserver. If more than one is needed they have to be separated by spaces.
nameserver = fd00::53:1 fd00::53:2
The domain to be used with FQDN hostnames for option 39 is given by domain.
domain = example.com
Domain search lists to be used with option 24 are configured by domain_search_list. If none is given the value of domain above is used. Multiple domains have to be separated by space or comma.
domain_search_list = foo.com bar.com
The ntp_server can be unicast addresses, multicast addresses or FQDNs following RFC 5908 for DHCPv6 option 56.
ntp_server = 2001:db8::123
Logging is set by log, log_console and log_file. The first triggers logging. The second simply prints log messages on that console where dhcpy6d has been started. The logfile defined by the third has to be created by the user manually in advance before starting the server.
log = yes log_console = no log_file = /path/to/dhcpy6d/log/file
Logging via syslog is possible with log_syslog set. An UDP syslog server may be used if log_syslog_destination points to it. Optionally a port other than default 514 can be set when adding “:” to the destination. The default syslog facility is “daemon” but can be set with log_syslog_facility.
log_syslog = yes log_syslog_destination = syslogserver log_syslog_facility = local1
Logging of discovered MAC/LLIP pairs of clients might be pretty verbose in larger setups and with disabled MAC/LLIP pair caching, this it is configurable with log_mac_llip:
log_mac_llip = no
Configuration of clients can be stored in a file or in a database. Databases MySQL, PostgreSQL and SQLite are supported at the moment, thus possible values are “file”, “mysql” and “sqlite”. To disable any client configuration source it has to be “none”. If store_config is set to “file” a file has to be set to get client configuration with store_file_config.
store_config = file store_file_config = /path/to/client/conf/file
Volatile data like leases and the mapping between Link Local Addresses and MAC addresses can be stored in MySQL, PostgreSQL or SQLite database, so the possible values for store_volatile are “mysql”, “postgresql” and “sqlite”. If set to “sqlite” a SQLite database file must be given.
store_volatile = sqlite store_sqlite_volatile = volatile.sqlite
If store_config is set to “sqlite” a SQLite file must be set as source for client configuration.
store_config = sqlite store_sqlite_config = /path/to/sqlite/config/file
If store_volatile is set to “mysql” the connection data for the MySQL database must be set.
store_volatile = mysql store_db_host = localhost store_db_db = dhcpy6d_db store_db_user = dhcpy6d_user store_db_password = dhcpy6d_password
The same MySQL or PostgreSQL settings are necessary if also client configuration is stored in MySQL or PostgreSQL database – but need to be set only once.
store_config = mysql store_volatile = mysql store_db_host = localhost store_db_db = dhcpy6d_db store_db_user = dhcpy6d_user store_db_password = dhcpy6d_password
The configured clients will be identified by at least one attribute. Attributes are
Thus identification has to be at least one of “mac”, “duid”, “hostname”.
identification = mac hostname
If more than one identification attribute has been set, identification_mode can be one of “match_all” or “match_some”. The first means that all attributes have to match to identify a client and the latter is more tolerant. This might be interesting if there are some dualboot clients whose MAC addresses match but their DUIDs don’t.
identification_mode = match_all
If serving only for delivering addresses regardless of classes (e.g. on PPP interface) MACs do not need to be investigated, thus ignore_mac can be enabled.
Dhcpy6d allows to update DNS dynamically with dns_update. This works at the moment only with Bind DNS, but might be extended to others, maybe via call of an external command.
dns_update = yes
When connecting to a Bind DNS server its address and RNDC data must be set with dns_update_nameserver, dns_rndc_key and dns_rndc_secret:
dns_update_nameserver = fd00::53:1 dns_rndc_key = rndc-key dns_rndc_secret = VDE8dje4sWsd93SKksdkk==
Clients may request that they update DNS. If these wishes shall be ignored dns_ignore_client is the right switch:
dns_ignore_client = yes
For DNS updates dhcpy6d can use the hostname supplied by the client or the one configured for the client in the database, set by dns_use_client_hostname:
dns_use_client_hostname = no
The various lifetimes an address has can be configured globally for all addresses, but if needed, they could get extra settings. Here are the general preferred_lifetime. valid_lifetime, t1 and t2:.
preferred_lifetime = 43200 valid_lifetime = 64800 t1 = 21600 t2 = 32400
The lifetime of information given to clients after an information-request message is set with information_refresh_time:
information_refresh_time = 7200