Technical data
4. Packages
• relay with two interfaces
• interface to the clients: eth0, 192.168.6.1
• interface to the DHCP-server: eth1, 192.168.7.1
• DHCP-server: 192.168.7.2
A route on the DHCP server has to exist over which the answers to 192.168.6.1 can reach
their destination. If the router on which the relay is running is the default gateway for
the DHCP server everything os fine already. If not, an extra route is needed. If the DHCP
server is a fli4l ythe following config variable is sufficient: IP_ROUTE_x=’192.168.6.0/24
192.168.7.1’
There may be warnings about ignoring certain packets which you may safely ignore.
Example:
OPT_DHCPRELAY='yes'
DHCPRELAY_SERVER='192.168.7.2'
DHCPRELAY_IF_N='2'
DHCPRELAY_IF_1='eth0'
DHCPRELAY_IF_2='eth1'
4.5.5. TFTP-server
To deliver files with the TFTP-protocol, a TFTP-server is needed. This may be useful for
netboot scenarios.
OPT_TFTP Activates the internal TFTP-server of the dnsmasq. Default setting is ’no’.
TFTP_PATH Specifies the folder, where the files to be delivered to the clients are stored.
The files have to be stored manually there.
4.5.6. YADIFA - Slave DNS Server
OPT_YADIFA Activates the YADIFA Slave DNS Server. Default Setting: ’no’.
OPT_YADIFA_USE_DNSMASQ_ZONE_DELEGATION If this setting is activated the
yadifa start script will automatically generate the according zone delegation entries for
dnsmasq. The slave zones can be queried directly from dnsmasq and basically YAD-
IFA_LISTEN_x entries not needed. Queries will only be forwarded to yadifa which is
listening on localhost:35353 and then answered by dnsmasq.
YADIFA_LISTEN_N If you specified OPT_YADIFA=’yes’ you may provide local IPs on which
yadifa is allowed to answer queries. YADIFA_LISTEN_N sets the number and YADIFA_LISTEN_1
to YADIFA_LISTEN_N the local IPs. A port number is otional, with 192.168.1.1:5353 teh
YADIFA Slave DNS Server would listen to DNS queries on port 5353. Please note that
dnsmasq is not allowed to listen on all interfaces in this case (see DNS_BIND_INTERFACES).
Only IPs of existing interfaces may be used here (ethernet, wlan ...) otherwise there will
be warning during router boot. As an alternative it is possible to use an ALIAS name,
like i.e. IP_NET_1_IPADDR
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