1DNRD(8) Domain Name Relay Daemon DNRD(8)
2
6 dnrd - proxy name server
7
9 dnrd [-a localaddress | --address=localaddress] [-b | --load-balance]
10 [-B BLACKLIST | --blacklist=BLACKLIST]
11 [-c (off|[low:]high) | --cache=(off|[low:]high)]
12 [-d LEVEL | --debug=LEVEL] [-h | --help] [-i | --ignore]
13 [-k | --kill] [-l | --log] [-m (off|FILE) | --master=(off|FILE)]
14 [-M N | --max-sock=N] [-r N | --retry=N]
15 [-R DIR | --dnrd-root=DIR]
16 [-s ipaddr(:domain) | --server=ipaddr(:domain)]
17 [-S N[+] | --stats=N[+]] [-t N | --timeout=N]
18 [-u userid | --uid=userid] [-v | --version]
19
21 dnrd is a proxying nameserver. It forwards DNS queries to the
22 appropriate nameserver, but can also act as the primary nameserver for
23 a subnet behind a firewall. Proxying is configured on the command line
24 using the -s option. By default, dnrd will act as the primary
25 nameserver for hosts found in /etc/dnrd/master and queries to hostnames
26 listed in /etc/dnrd/blacklist will be answered with a "host not found".
27
30 -a
31 --address
33 Bind only to the interface with the specified address. By
34 default dnrd binds to everything.
35 -b
38 --load-balance
40 Turn on load balancing. All forward servers (specified with -s)
41 after this option will load balance in a round robin scheme. By
42 default, dnrd will use the next server in the list if the first
43 times out. As soon as the first is reactivated, it will be used
44 again. With -b option, dnrd will use next active server as soon
45 a request is served. If a server times out it will be
46 deactivated and will not be used until it comes back. As soon it
47 is reactivated it will join the list.
48 Note that if there are no servers specified with -s after the
50 -b, this will do nothing at all.
51 -B BLACKLIST
54 --blacklist=BLACKLIST
56 Blacklist all hostnames listed in the file BLACKLIST. Queries to
57 hosts listed in this file will be answered with "host not
58 found". The file BLACKLIST is specified relative to the DNRD
59 chroot directory (defaults to /etc/dnrd). By default dnrd will
60 look for a file named "blacklist".
61 -c (off|[low:]high)
64 --cache=(off|[low:]high)
66 This option can be used to either turn off caching of DNS
67 responses, or to change the high and low watermarks. With the
68 high/low water mark option, cached entries are purged when the
69 number of responses reaches the high-water mark, and they will
70 be purged until the number of cached responses reaches the
71 low-water mark, purging the oldest first. By default, caching is
72 on, with low and high water-marks of 800 and 1000 respectively.
73 -d LEVEL
76 --debug=LEVEL
78 This turns on debugging level LEVEL. The dnrd process will not
79 fork into the background and print out debugging information in
80 the current console. Supported debug levels are 1-4 The higher
81 level, the more debug info is printed.
82 The -l option can be used to force dnrd to run in the background
84 and log debug info to syslog.
85 Sending signal SIGUSR1 will toggle the debug level between level
87 0 (no debugging) and level 3.
88 -h
91 --help Prints usage information
93 -i
96 --ignore
98 Ignore cache for deactivated servers. If a forward DNS server
99 times out and gets deactivated, all cache entries for this
100 server are ignored. This helps avoid network timeout delays when
101 dnrd serves a offline/dialup network.
102 -k
105 --kill Kills the currently running dnrd process.
107 -l
110 --log Send all messages to syslog. dnrd uses the deamon facility. If
112 used with the -d flag, this option will cause dnrd to fork and
113 run in the background, logging all debugging messages to syslog.
114 -m (off|FILE)
117 --master=(off|FILE)
119 dnrd can act as the primary name server for a number of hosts.
120 By default, it will read in /etc/dnrd/master to determine how
121 this is done. This option specifies another file than
122 /etc/dnrd/master or turns off all primary server functionality.
123 Sending dnrd signal -HUP will make dnrd try to re-read the
124 master file unless this is option is set to "off". Therefore,
125 the master file have to be within the dnrd-root. the file is
126 specified relative to dnrd-root.
127 -M N
131 --max-sock=N
133 Set the maximum allowed open sockets. Default is 200.
134 -r N
138 --retry=N
140 Set the retry interval time. When a forward DNS server times out
141 it is deactivated. (use the -t option to set the timeout value)
142 dnrd will try to send a request for localhost every N seconds.
143 As soon there are a respose from a deactivated server, it is
144 reactivated. The default value is 10 seconds. Setting this to
145 zero will make dnrd to never deactivate a server.
146 -R DIR
150 --dnrd-root=DIR
152 Set the dnrd-root to DIR. dnrd will chroot to this directory at
153 startup so all files, masterfile and blacklist, must be here.
154 This option overrides the environment variable DNRD_ROOT.
155 Default dnrd-root is /etc/dnrd.
156 -s ipaddr(:domain)
160 --server=ipaddr(:domain)
162 Add a forward DNS server. If -s is used multiple times, the
163 first is the primary DNS server and the rest are backup servers.
164 If the primary DNS server times out, it is deactivated and the
165 next specified server (that is active) is used until the
166 previous gets reactivated.
167 The domain option allows dnrd to determine which DNS server
169 should get the query based on the domain name in the query. This
170 is useful when you have an internet connection and a vpn
171 connection to work, for instance. Several servers with the same
172 domain might be specified and then will they work as backup
173 servers.
174 If the -b option is specified, then all servers specified after
176 the -b option are load balanced per domain.
177 -S N[+]
181 --stats=N[+]
183 Print statistics about cache hits, cache misses and timeouts to
184 syslog every N seconds. If + is specified, the counters will
185 not be reset after the print.
186 -t N
189 --timeout=N
191 Set the timeout value for forward DNS servers. If a server don't
192 respond to a query within N seconds it is deactivated. The
193 default value is 12
194 Setting this to zero will make dnrd to never deactivate a server
196 because of timeouts. However, a server might be deactivated if
197 sendto fails.
198 -u userid
202 --userid=userid
204 Set the UID that dnrd will run as. By default, dnrd tries to
205 switches to uid dnrd after starting up.
206 -v
210 --version
212 Prints out the version number.
213
216 The TTL's are not respected for the cache.
217
220 /etc/dnrd/master
221 This file is used to configure dnrd as a primary nameserver.
223 /etc/dnrd/blacklist
225 Hosts listed in this file are blacklisted.
227 /var/run/dnrd.pid
229 The currently-running dnrd process' pid is placed into this file. It is
231 needed to allow new dnrd processes to find and kill the currently
232 running process.
233
236 The original version of dnrd was written by Brad Garcia garsh@home.com.
237 Other contributors are listed in the HISTORY file included with the
238 source code.
239DNRD v2.20 Domain Name Relay Daemon DNRD(8)