Technical data

4. Packages

DNS_REDIRECT_N='1'

DNS_REDIRECT_1='yourdom.dyndns.org'

DNS_REDIRECT_1_IP='192.168.6.200'

This redirects a query of yourdom.dyndns.org to IP 192.168.6.200.

DNS_BOGUS_PRIV If you set this variable to ‘yes‘, reverse-lookups for IP-Addresses of

RFC1918 (Private Address Ranges) are not redirected to other DNS-servers but rather

answered by the dnsmasq.

DNS_FILTERWIN2K If this is set to ’yes’ DNS queries of type SOA, SRV, and ANY will be

blocked. Services using these queries will not work anymore without further conﬁgura-

tion.

For example:

• XMPP (Jabber)

• SIP

• LDAP

• Kerberos

• Teamspeak3 (as of client-version 3.0.8)

• Minecraft (as of full version 1.3.1)

• domain controller discovery (Win2k)

For further information:

• Explanantion of DNS query types in general:

http://en.wikipedia.org/wiki/List_of_DNS_record_types

• dnsmasq manpage:

http://www.thekelleys.org.uk/dnsmasq/docs/dnsmasq-man.html

• SRV queries in detail:

http://en.wikipedia.org/wiki/SRV_resource_record

By setting this to ’no’, additionally forwarded DNS queries may cause un-

wanted dial-up connections or prevent existing ones from being closed. Par-

ticularly if you are using ISDN or UMTS connections additional costs may

arise. You have to choose for yourself what’s more important to you.

DNS_FORWARD_LOCAL By setting this variable to ’yes’ ﬂi4l-routers may be conﬁgured to

be in a domain by the name of DOMAIN_NAME=’example.local’ whose name resolution

will be done by another name server speciﬁed by DNS_SPECIAL_x_DOMAIN=’example.local’.

DNS_LOCAL_HOST_CACHE_TTL deﬁnes the TTL (Time to live, in seconds) for entries

deﬁned in /etc/hosts as well as for hosts listed in DHCP. The default value for the ﬂi4l-

router is 60 seconds. Dnsmasq uses 0 as default and thus disables caching of DNS entries.

The idea behind that is to reuse DHCP leases that are running out fastly and pass them

on swiftly. However, if for example a local IMAP proxy queries the DNS entries several

times per second this is a signiﬁcant burden on the network. A compromise is a relatively

short TTL of 60 seconds. Even without the short TTL 60 seconds a host can always