[CTX] [ALL]

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RESOLV parameter    ==  RESOLV=[resolver[,resolver]*]
          resolver  ==  resType[:[resParam][:[queryHostList][:clientHostList]]]
           resType  ==  cache | file | nis | dns | sys
                    --  default: RESOLV=cache,file,nis,dns,sys

Specify which name resolver should be used in what order.

cache	-- means cached result from following resolvers
file	-- means local hosts(5) file usually located at /etc/hosts,
nis	-- means hosts map on NIS or YP(4) service,
dns	-- means DNS service, and
sys	-- means using gethostbyname(2) and gethostbyaddr(2) which usually call system's standard resolver of the host.

If RESOLV is not specified, "sys" is disabled if the IP-address of the host of DeleGate is resolvable by "dns".
If empty value is specified as RESOLV="" then only hosts listed in HOSTS parameter can be resolved (this could be useful when you must hide hosts table for security consideration). Each resolver can be specified with optional argument like follows:

cache:/path	-- path name of cache directory [$TMPDIR/resolvy]
file:/path	-- path name of host-name file [/etc/hosts]
nis:nisDomain	-- NIS domain name [default domain]
dns:dnsHost	-- (a list of) DNS server

DNS Routing: A resolver can be applied to specific queries from specific clients. The optional queryHostList specifies for which hosts or addresses the resolver is applied. The optional clientHostList specifies for which client hosts the resolver is applied.

Example: selecting DNS servers depending on the inquired host/address

RESOLV="cache,dns:{192.168.1.2:8053}:{192.168.*,*.localdomain},dns:192.168.1.1"
// resolve local hosts with DNS sever at 192.168.1.2:8053
// and resolve others with 192.168.1.1:53
// this can be decomposed into a set of parameters like follows:
RESOLV="cache,dns:local-dns:local-hosts,dns:192.168.1.1"
HOSTLIST=local-dns:192.168.1.2:8053
HOSTLIST=local-hosts:192.168.*,*.localdomain


Example: selecting resolvers depending on the inquiring (client) DNS host

RESOLV="file:/etc/hosts:localHosts:192.168.*,dns:xx.xx.xx.xx"
HOSTLIST="localHosts:192.168.*,*.localdomain,*.mydomain"
// queries from local hosts (192.168.*) for "localHosts" are resolved
// with the file "/etc/hosts", others are resolved with the DNS server "xx.xx.xx.xx".

By default, a connection to a host which has multiple IP addresses is tried for each address in the order they are defined in each resolver. A special parameter HOSTS="*/*/RR" can be added to specify "Round Robin" where those IP addresses are tried in round robin order.

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