17. DNS 서버 실습

DNS실습 정리도

내 PC내에서 만 일어나기때문에 포트포워딩 불필요!
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DNS 서버
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1 리눅스에서 DNS서버(bind)
  1) 설치
yum install bind

  2) 설정 파일
/etc/named.conf

2 named.conf 파일

  1) 기본 설정
options {
        directory "/var/named"; //영역파일의 위치, 영역을 표시한다
}; //마지막엔 세미콜론


zone "sjb.com" in {
        type master;  //마스터 서버 slave 보조서버.
        file "sjb.com.zone"; //sjb파일의 도메인 주소를 저장.
};



옵션이라는 부분에 서버에 설정

  2) 설정 확인
named-checkconf 출력 결과가 없으면 정상
출력시 에러


3 zone 영역 파일
  1) 영역 파일 설정
[vi] /var/named/sjb.com.zone //처음엔 다 비여있음 //앞에 ;가 있으면 주석

;(name)         (ttl)   CLASS   TYPE    Origin          DNSMaster
;-------------------------------------------------------------------------------
$TTL 1D //(Time to Live  1Day)
@                       IN      SOA     ns.sjb.com.     root.sjb.com. (
                                        2023020901      ;serial number
                                        3600            ;Refresh
                                        1800            ;Retry
                                        36000           ;Expire
                                        86400           );TTL

//ns(name server) 관리자 주소(
//영역파일에 시리얼 번호(마스터, 슬레이브 업데이트 보통 날짜를 작성함)
//업데이트 주기 (3600초)
//언제한번 다시시도하는가(1800초)
//얼마까지 다시 시도하는가 이시간이 넘으면 새로고침안함(36000초)
//

;(name)         (ttl)   CLASS   TYPE    Value
;-------------------------------------------------------------------------------
                        IN      NS      ns.sjb.com.
ns                      IN      A       [ip주소]
www                 IN      A       [ip주소]
news                 IN      A       [ip주소]
server IN CNAME www

// NS(Dns서버) 
//ns라는 친구는 ns라는 서버를쓴다
// 내PC주소
// 서버주소
// 벌명
TYPE
NS : 이름 서버
A : IPv4 주소
AAAA : IPv6 주소
MX : 메일 서버
CNAME : 별


  2) 영역 파일 설정 확인
named-checkzone [도메인] [영역파일] OK가 뜨면 문제가 없음



4 루트 힌트 서버 추가

  1) /etc/named.conf

zone "." in {
        type hint;
        file "named.root";
};


  2) 루트 힌트 서버 파일 다운
cd /var/named

wget https://www.internic.net/domain/named.root

  3) 서비스 재시작
설정이 변경되었으니 서비스를 한 번 재시작한다.
systemctl restart named

  4) 확인
nslookup
server [본인 리눅스IP]
www.naver.com 를 물어봤을 때 제대로 알려주면 성공

dig @192.168.240.100  www.naver.com       A        +trace
    [물어 볼 DNS서버]    [물어볼 도메인]   [레코드 타입]   [경로 추적 옵션]




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실습


존 영역 파일 공유 실습



cmd

nslookup

set type=all
(반복)

[도메인]

server [DNS 서버]

ls -d [도메인]

server 8.8.8.8

5. 보안 설정

  1) /etc/named.conf
options {
        directory "/var/named";
        allow-query { any; }; // 내 DNS 서버에게 물어볼 수 있는 컴퓨터
        allow-transfer { 192.168.214.0/24; }; // 내 DNS 서버에게 zone 영역 파일을 받아갈 수 있는 컴퓨터
};


6. 보조 DNS 서버(영역 전송)
  1) 보조 DNS 서버 준비
리눅스 설치
네트워크 설정
DNS 서버 설치


  2) /etc/named.conf
options {
        directory "/var/named";
};

zone "sjb.com" in {
        type slave;
        file "slaves/sjb.com.zone";
        masters { 192.168.240.100; };
};

  3) 마스터에서 알람 설정
options {
        directory "/var/named";
        allow-query { any; };
        allow-transfer { 192.168.214.0/24; };
        notify yes; // 슬레이브에게 변경된 사항을 알려주는 설정, slave는 영역 파일에서 NS 타입으로 된 주소의 서버
};


  4) 마스터에서 영역 파일 수정

;(name)         (ttl)   CLASS   TYPE    Origin          DNSMaster
;-------------------------------------------------------------------------------
$TTL 1D
@                       IN      SOA     ns.sjb.com.     root.sjb.com. (
                                        2023020905      ;serial number
                                        3600            ;Refresh
                                        1800            ;Retry
                                        36000           ;Expire
                                        86400           );TTL

;(name)         (ttl)   CLASS   TYPE    Value
;-------------------------------------------------------------------------------
                        IN      NS      ns.sjb.com.
                        IN      NS      ns2.sjb.com.
ns                      IN      A       192.168.214.100
ns2                     IN      A       192.168.214.200
www                     IN      A       192.168.0.222
server                  IN      CNAME   www