| iluvAS |
07-17-2011 08:12 AM |
Setting up DNS in RHEL5 (newbie)
Hi there, I've been googling for solutions but I couldn't find much that explains how named.conf and zone files work. Anyways for my school project using RHEL5 I am suppose to set up the following:
- a DNS master server for the domain p0920948.com
- I will be using bind-chroot
- I have two machines one server (172.16.112.39/24) and another client (172.16.112.40/24)
- Client has to be able to ping server by p0920948S1.p0920948.com
- This part im not sure what it means by "dig" but its in the instructions: dig p0920948S1.p0920948.com
- Client able to ping server by aliased www.p0920948.com
- client able to ping itself by p0920948C1.p0920948.com
So what I've done so far is - install bind and chroot
- write the command chkconfig named on to start it on boot
- Copied some files from /usr/share/doc/bind-*/sample into chroot
- Modified resolve.config adding in "nameserver 127.0.0.1" for localhost
- Add in "listen-on port 53 {127.0.0.1; 172.16.112.39; 172.16.112.40};" under the options bracket in named.conf
- declared an acl "safe-subnet" {172.16.112.0/24}; and added it into the match-clients and match-destinations for internal
- And within internal i added in a zone file refrence
- I modified named.root.hints to add in a zone reference as well
- Created the zone file
NAMED.CONF FILE
Code:
//
// Sample named.conf BIND DNS server 'named' configuration file
// for the Red Hat BIND distribution.
//
// See the BIND Administrator's Reference Manual (ARM) for details, in:
// file:///usr/share/doc/bind-*/arm/Bv9ARM.html
// Also see the BIND Configuration GUI : /usr/bin/system-config-bind and
// its manual.
//
options
{
listen-on port 53 { 127.0.0.1; 172.16.112.39; 172.16.112.40; };
// Those options should be used carefully because they disable port
// randomization
// query-source port 53;
// query-source-v6 port 53;
// Put files that named is allowed to write in the data/ directory:
directory "/var/named"; // the default
dump-file "data/cache_dump.db";
statistics-file "data/named_stats.txt";
memstatistics-file "data/named_mem_stats.txt";
};
logging
{
/* If you want to enable debugging, eg. using the 'rndc trace' command,
* named will try to write the 'named.run' file in the $directory (/var/named).
* By default, SELinux policy does not allow named to modify the /var/named directory,
* so put the default debug log file in data/ :
*/
channel default_debug {
file "data/named.run";
severity dynamic;
};
};
//
// All BIND 9 zones are in a "view", which allow different zones to be served
// to different types of client addresses, and for options to be set for groups
// of zones.
//
// By default, if named.conf contains no "view" clauses, all zones are in the
// "default" view, which matches all clients.
//
// If named.conf contains any "view" clause, then all zones MUST be in a view;
// so it is recommended to start off using views to avoid having to restructure
// your configuration files in the future.
//
view "localhost_resolver"
{
/* This view sets up named to be a localhost resolver ( caching only nameserver ).
* If all you want is a caching-only nameserver, then you need only define this view:
*/
match-clients { localhost; };
match-destinations { localhost; };
recursion yes;
# all views must contain the root hints zone:
include "/etc/named.root.hints";
/* these are zones that contain definitions for all the localhost
* names and addresses, as recommended in RFC1912 - these names should
* ONLY be served to localhost clients:
*/
include "/etc/named.rfc1912.zones";
};
acl "safe-subnet" { 172.16.112.0/24; };
view "internal"
{
/* This view will contain zones you want to serve only to "internal" clients
that connect via your directly attached LAN interfaces - "localnets" .
*/
match-clients { localnets; localhost; safe-subnet; };
match-destinations { localnets; localhost; safe-subnet; };
recursion yes;
// all views must contain the root hints zone:
include "/etc/named.root.hints";
// include "named.rfc1912.zones";
// you should not serve your rfc1912 names to non-localhost clients.
// These are your "authoritative" internal zones, and would probably
// also be included in the "localhost_resolver" view above :
zone "p0920948.com" {
type master;
notify no;
allow-query { any; };
file "var/named/zones/internal/p0920948.zone";
};
zone "my.internal.zone" {
type master;
file "my.internal.zone.db";
};
zone "my.slave.internal.zone" {
type slave;
file "slaves/my.slave.internal.zone.db";
masters { /* put master nameserver IPs here */ 127.0.0.1; } ;
// put slave zones in the slaves/ directory so named can update them
};
zone "my.ddns.internal.zone" {
type master;
allow-update { key ddns_key; };
file "slaves/my.ddns.internal.zone.db";
// put dynamically updateable zones in the slaves/ directory so named can update them
};
};
key ddns_key
{
algorithm hmac-md5;
secret "use /usr/sbin/dns-keygen to generate TSIG keys";
};
view "external"
{
/* This view will contain zones you want to serve only to "external" clients
* that have addresses that are not on your directly attached LAN interface subnets:
*/
match-clients { any; };
match-destinations { any; };
recursion no;
// you'd probably want to deny recursion to external clients, so you don't
// end up providing free DNS service to all takers
allow-query-cache { none; };
// Disable lookups for any cached data and root hints
// all views must contain the root hints zone:
include "/etc/named.root.hints";
// These are your "authoritative" external zones, and would probably
// contain entries for just your web and mail servers:
zone "my.external.zone" {
type master;
file "my.external.zone.db";
};
};
NAMED ROOT HINTS
Code:
//
// The 'named.root' root cache hints zone for the bind DNS 'named' nameserver.
//
// named's cache must be primed with the addresses of the root zone '.' nameservers.
// The root zone file can be obtained by querying the root 'A' nameserver:
// $ dig . ns @198.41.0.4 > named.root
// Or by download via FTP / HTTP:
// $ wget ftp://ftp.rs.internic.net/domain/named.root
//
// Every view that is to provide recursive service must include this zone.
//
zone "." IN {
type hint;
file "named.root";
};
zone "p09209498.com" IN {
type master;
file "/var/named/zones/internal/p0920948.zone";
allow-update { none; };
};
zone file "p0920948.zone"
Code:
;
; Zone file for p0920948.com
;
; The full zone file
;
$TTL 3D
@ IN SOA www.p0920948.com. hostmaster.p0920948.com. (
200211152 ; serial#
3600 ; refresh, seconds
3600 ; retry, seconds
3600 ; expire, seconds
3600 ) ; minimum, seconds
NS www ; Inet Address of nameserver
p0920948S1.p0920948.com. A 10 p0920948S1 ; Server
p0920948C1.p0920948.com. A 10 p0920948C1 ; Client
p0920948S1 A 172.16.112.39
p0290948C1 A 172.16.112.40
www CNAME p0920948S1
INTERNAL_ZONES.CONF
Code:
zone "p09209498.com" IN {
type master;
file "/var/named/zones/internal/p0920948.zone";
allow-update { none; };
};
After all that when i execute the /etc/init.d/named restart command, i got bombarded with errors and I tried debugging line by line and gave up when i realize its due to my lack of the concept on how zone files work and me copying chunks of code i find online thats causing the errors. So it would be great if anyone can help explain the concept or point out some of the mistakes i make.
Thanks for reading my epicly long post, any help will be greatly appreciated. |
