<<DNS Balance>>
By: YOKOTA Hiroshi <yokota@netlab.is.tsukuba.ac.jp>
[1. What's this]
DNS Balance is a load-balancing DNS server.
Today's Web server, like "kernel.org", "*bsd.org" and Ring Server Project
(http://www.ring.gr.jp/) are mirrored all over the world. DNS Balance
selects fast server from all over the world for DNS resolver.
DNS Balance has these functions:
o Dynamic load balancing.
o Answer different IP address between DNS client's IP address.
o Minimun implement. This may be good for security.
[2. What you need]
DNS Balance requires Ruby (http://www.ruby-lang.org/).
So, you must install it. Some PC-UNIX has binary packages.
[3. What you do]
1. Extract the archive in "/usr/local/share". If you want to extract another
directory, change "$prefix" in script "dns_balance.rb".
2. File "addrdb.rb" is the address database. You must edit this for
your site.
------------------
$addr_db = {
"130.12.0.0/16" => { # => Request from 130.12.0.0/16
# For example, DNS client's IP is
# "123.45.67.89", search "123.45.67.89/32" to
# "0.0.0.0/1".
"www.foo.com" => [ # => IP address for "www.foo.com"
# This host name must be lower case character.
[[1,2,3,4], 0], # => IP address and badness information.
[[1,2,3,5], 10000], # Badness must be 0-10000. 0 is for fastest
[[1,2,3,6], 9000], # server, and 10000 is for downed server.
[[1,2,3,7], 9000],
],
},
"default" => { # => If theres nothing to match, use "default".
"www.foo.com" => [
[[1,2,3,4], 0],
[[1,2,3,5], 100],
[[1,2,3,6], 1000],
[[1,2,3,7], 9000],
],
"localhost" => [
[[127,0,0,1], 0],
],
},
}
------------------
3. If your addrdb.rb is too complex to maintain, you can use namespace.rb .
------------------
$namespace_db = {
"127.0.0.0/8" => "localnet", # Write IP address and its alias name.
"192.168.0.0/16" => "foo-net", # If client IP is 123.45.67.89, search
"130.199.0.0/16" => "foo-net", # "123.45.67.89/32" to "0.0.0.0/1".
"130.123.12.0/28" => "foo-net",
}
------------------
If you use namespace.rb , you can write this way.
------------------
$addr_db = {
"localnet" => {
"www.foo.com" => [
[[1,2,3,6], 2000],
[[1,2,3,7], 1000],
],
},
"foo-net" => {
"www.foo.com" => [
[[1,2,3,4], 0],
[[1,2,3,5], 100],
],
},
"default" => {
"www.foo.com" => [
[[1,2,3,4], 0],
[[1,2,3,5], 10000],
[[1,2,3,6], 9000],
[[1,2,3,7], 9000],
],
},
}
------------------
4. You can use "--as" option to use "Autonomous System" information
from whois.ra.net .
whois.ra.net offers AS information.
---------
$ whois -h whois.ra.net 192.168.0.1
route: 192.168.0.0/24
descr: Foo networks
origin: AS1000 <==================== This is AS information
member-of: RS-COMM_FOONET
mnt-by: MAINT-AS1000
changed: rm@foo.ad.jp 99999999
source: BARNET
---------
You can use AS information like this.
--------------
$addr_db = {
"AS1000" => {
"www.foo.com" => [
[[1,2,3,4], 0],
],
},
"default" => {
"www.foo.com" => [
[[1,2,3,4], 0],
[[1,2,3,5], 10000],
],
},
}
--------------
5. Run DNS Balance. Type "ruby /usr/local/lib/DNS-Balance-x.x/dns_balance.rb"
for run DNS Balance.
6. If exists a file named "addr", DNS Balance is loads automatically every
5 minutes. This file contains same database as "addrdb.rb".
I make some sample script like CSV -> address database converter.
See "sample" directory
7. "-i xxx.xxx.xxx.xxx" to specify listen IP address.
And "-h" to display some help message.
[4. Copyright]
See README.dns_balance.
If you want newer version, see my homepage.
URL http://www.netlab.is.tsukuba.ac.jp/~yokota/
http://www.netlab.is.tsukuba.ac.jp/~yokota/izumi/dns_balance/
Any questions and suggestions are welcome.
2002/09/06: YOKOTA Hiroshi (yokota@netlab.is.tsukuba.ac.jp)