Tuesday, January 8, 2013

DNS notes

first record of the zone is source of authority..

usually prefix using @ sign folllowed by tab followed by IN internet type followed by SOA source of authority followed by domain in our case localhost followed by domain owner in our case root followed by open parenthesis for few settings...

@     IN SOA    localhost    root (
   
now just below SOA we define serial number yymmdd-01 followed by semicolum

        2010081801;    SERIAL number
        1D      ;    refresh => refresh rate is 1 day
        1H      ;    retry  ==> retry pperiod set to 1 hrs
        1W      ;    expiration ==>> how long zone period expires 1 week
        1D )      ;     min    86400 sec -->> min time some can hold this information.
       
// make sure to close the parenthesis. this all section is source of authority for a given zone now specify the name server

IN type record IN name server NS record  @ (means domain here in our case localhost)
IN     NS     @

now define the resource record. zone file should contain resource record..
resource record is defined by A (address resource record) points to the hosts so we use its ipaddress which is locahost ip address 127.0.0.1

now on reverse zone

we modify soa file just adding . on the domain like localhost. followed by root.localhost.

on the NS instead of @ we use the domain that is localhost.
on the A address record we use PTR pointer record followed by localhost.

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DNS record types

A ==>> COmmonly used to map hostnames to an ip address of the host
AAAA - ipv6 map hostnames to an ip address of the host
CNAME ==> Alias of one name to another.
MX =>> Maps a domain name to a list of message transfer agent (MTA) for that domain
NS => Delegates a DNS zone to use the given authoritative name server...
PTR => Pointer to a canonical name. use for reverse DNS lookup.

SOA =>> Start of authority=>>    Specifies anthoritative information about a DNS zone, including primary name server, e-mail of domain admin, domain serial number, timer related to refreshing the zone..

Incomplete note:

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