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웹 서버에 접속할 수 없지만 SSH를 통해 접속할 수 있습니다.

tag-icon • tag-icon ubuntu networking apache-httpd ping
웹 서버에 접속할 수 없지만 SSH를 통해 접속할 수 있습니다.

Ubuntu 서버가 있는데 이해할 수 없는 이상한 일이 일어나고 있습니다.

IP 주소로 서버를 핑할 수는 없지만 ssh를 통해 서버에 연결할 수는 있습니다. 명령줄을 통해 서버 내부의 Apache 서버에 액세스할 수 있지만 Windows 브라우저에서는 액세스할 수 없습니다.

지금 어떤 설정을 확인해야 합니까?

답변1

다음 도구를 사용하여 문제를 디버깅할 수 있습니다.

  1. wireshark또는를 실행 tcpdump하고 HTTP 요청이 서버에 도달하는지 확인합니다.

  2. 사용tcptraceroute

    $ tcptraceroute "webserver-ip" 80

  3. 웹 서버가 모든 인터페이스(0.0.0.0)가 아닌 로컬 호스트(127.0.0.1)에서만 수신 대기할 수도 있습니다.

    $ sudo netstat -taupen | grep LISTEN

  4. 다음 명령을 사용하여 iptables 규칙을 확인하십시오.

    $ sudo iptables -nvL

  5. 방화벽 역할도 하는 SELinux의 상태를 확인합니다.

    $ sudo sestatus

답변2

  1. 액세스를 차단하는 방화벽 규칙이 있을 수 있습니다. 출력을 확인하십시오 iptables -L. SSH를 제외한 모든 것이 차단되었을 수도 있습니다.

  2. 이러한 서비스는 올바른 인터페이스나 포트에서 수신 대기하지 않을 수 있습니다. 출력을 확인하십시오 netstat -ntl.

이러한 명령이 문제 해결에 도움이 되지 않으면 질문에 해당 명령의 출력을 추가하세요. 출력도 추가되었습니다 ifconfig.

답변3

나에게도 이 문제가 있다. 위 명령의 일부 출력은 다음과 같습니다.

# netstat -taupen | grep LISTEN
tcp        0      0 0.0.0.0:139             0.0.0.0:*               LISTEN      0          19239      2490/smbd
tcp        0      0 0.0.0.0:10000           0.0.0.0:*               LISTEN      0          19149      2475/perl
tcp        0      0 0.0.0.0:22              0.0.0.0:*               LISTEN      0          18616      1241/sshd
tcp        0      0 127.0.0.1:25            0.0.0.0:*               LISTEN      0          20281      2487/master
tcp        0      0 0.0.0.0:445             0.0.0.0:*               LISTEN      0          19238      2490/smbd
tcp6       0      0 :::8009                 :::*                    LISTEN      91         19311      1247/java
tcp6       0      0 :::139                  :::*                    LISTEN      0          19237      2490/smbd
tcp6       0      0 :::80                   :::*                    LISTEN      0          163453     4050/httpd
tcp6       0      0 :::8080                 :::*                    LISTEN      91         19310      1247/java
tcp6       0      0 :::21                   :::*                    LISTEN      0          19479      1282/vsftpd
tcp6       0      0 :::22                   :::*                    LISTEN      0          18618      1241/sshd
tcp6       0      0 ::1:25                  :::*                    LISTEN      0          20282      2487/master
tcp6       0      0 :::445                  :::*                    LISTEN      0          19236      2490/smbd
tcp6       0      0 127.0.0.1:8005          :::*                    LISTEN      91         20467      1247/java

# netstat -ntl
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address           Foreign Address         State
tcp        0      0 0.0.0.0:139             0.0.0.0:*               LISTEN
tcp        0      0 0.0.0.0:10000           0.0.0.0:*               LISTEN
tcp        0      0 0.0.0.0:22              0.0.0.0:*               LISTEN
tcp        0      0 127.0.0.1:25            0.0.0.0:*               LISTEN
tcp        0      0 0.0.0.0:445             0.0.0.0:*               LISTEN
tcp6       0      0 :::8009                 :::*                    LISTEN
tcp6       0      0 :::139                  :::*                    LISTEN
tcp6       0      0 :::80                   :::*                    LISTEN
tcp6       0      0 :::8080                 :::*                    LISTEN
tcp6       0      0 :::21                   :::*                    LISTEN
tcp6       0      0 :::22                   :::*                    LISTEN
tcp6       0      0 ::1:25                  :::*                    LISTEN
tcp6       0      0 :::445                  :::*                    LISTEN
tcp6       0      0 127.0.0.1:8005          :::*                    LISTEN

IP 테이블 출력:

# iptables -L
Chain INPUT (policy ACCEPT)
target     prot opt source               destination
ACCEPT     all  --  anywhere             anywhere             ctstate RELATED,ESTABLISHED
ACCEPT     all  --  anywhere             anywhere
INPUT_direct  all  --  anywhere             anywhere
INPUT_ZONES_SOURCE  all  --  anywhere             anywhere
INPUT_ZONES  all  --  anywhere             anywhere
ACCEPT     icmp --  anywhere             anywhere
REJECT     all  --  anywhere             anywhere             reject-with icmp-host-prohibited

Chain FORWARD (policy ACCEPT)
target     prot opt source               destination
ACCEPT     all  --  anywhere             anywhere             ctstate RELATED,ESTABLISHED
ACCEPT     all  --  anywhere             anywhere
FORWARD_direct  all  --  anywhere             anywhere
FORWARD_IN_ZONES_SOURCE  all  --  anywhere             anywhere
FORWARD_IN_ZONES  all  --  anywhere             anywhere
FORWARD_OUT_ZONES_SOURCE  all  --  anywhere             anywhere
FORWARD_OUT_ZONES  all  --  anywhere             anywhere
ACCEPT     icmp --  anywhere             anywhere
REJECT     all  --  anywhere             anywhere             reject-with icmp-host-prohibited

Chain OUTPUT (policy ACCEPT)
target     prot opt source               destination
OUTPUT_direct  all  --  anywhere             anywhere

Chain FORWARD_IN_ZONES (1 references)
target     prot opt source               destination
FWDI_internal  all  --  anywhere             anywhere            [goto]
FWDI_internal  all  --  anywhere             anywhere            [goto]

Chain FORWARD_IN_ZONES_SOURCE (1 references)
target     prot opt source               destination

Chain FORWARD_OUT_ZONES (1 references)
target     prot opt source               destination
FWDO_internal  all  --  anywhere             anywhere            [goto]
FWDO_internal  all  --  anywhere             anywhere            [goto]

Chain FORWARD_OUT_ZONES_SOURCE (1 references)
target     prot opt source               destination

Chain FORWARD_direct (1 references)
target     prot opt source               destination

Chain FWDI_internal (2 references)
target     prot opt source               destination
FWDI_internal_log  all  --  anywhere             anywhere
FWDI_internal_deny  all  --  anywhere             anywhere
FWDI_internal_allow  all  --  anywhere             anywhere

Chain FWDI_internal_allow (1 references)
target     prot opt source               destination

Chain FWDI_internal_deny (1 references)
target     prot opt source               destination

Chain FWDI_internal_log (1 references)
target     prot opt source               destination

Chain FWDO_internal (2 references)
target     prot opt source               destination
FWDO_internal_log  all  --  anywhere             anywhere
FWDO_internal_deny  all  --  anywhere             anywhere
FWDO_internal_allow  all  --  anywhere             anywhere

Chain FWDO_internal_allow (1 references)
target     prot opt source               destination

Chain FWDO_internal_deny (1 references)
target     prot opt source               destination

Chain FWDO_internal_log (1 references)
target     prot opt source               destination

Chain INPUT_ZONES (1 references)
target     prot opt source               destination
IN_internal  all  --  anywhere             anywhere            [goto]
IN_internal  all  --  anywhere             anywhere            [goto]

Chain INPUT_ZONES_SOURCE (1 references)
target     prot opt source               destination

Chain INPUT_direct (1 references)
target     prot opt source               destination

Chain IN_internal (2 references)
target     prot opt source               destination
IN_internal_log  all  --  anywhere             anywhere
IN_internal_deny  all  --  anywhere             anywhere
IN_internal_allow  all  --  anywhere             anywhere

Chain IN_internal_allow (1 references)
target     prot opt source               destination
ACCEPT     udp  --  anywhere             224.0.0.251          udp dpt:mdns ctstate NEW
ACCEPT     tcp  --  anywhere             anywhere             tcp dpt:http ctstate NEW
ACCEPT     udp  --  anywhere             anywhere             udp dpt:ipp ctstate NEW
ACCEPT     tcp  --  anywhere             anywhere             tcp dpt:ssh ctstate NEW
ACCEPT     udp  --  anywhere             anywhere             udp dpt:netbios-ns ctstate NEW
ACCEPT     udp  --  anywhere             anywhere             udp dpt:netbios-dgm ctstate NEW

Chain IN_internal_deny (1 references)
target     prot opt source               destination

Chain IN_internal_log (1 references)
target     prot opt source               destination

Chain OUTPUT_direct (1 references)
target     prot opt source               destination
[root@localhost etc]# iptables -L
Chain INPUT (policy ACCEPT)
target     prot opt source               destination
ACCEPT     all  --  anywhere             anywhere             ctstate RELATED,ESTABLISHED
ACCEPT     all  --  anywhere             anywhere
INPUT_direct  all  --  anywhere             anywhere
INPUT_ZONES_SOURCE  all  --  anywhere             anywhere
INPUT_ZONES  all  --  anywhere             anywhere
ACCEPT     icmp --  anywhere             anywhere
REJECT     all  --  anywhere             anywhere             reject-with icmp-host-prohibited

Chain FORWARD (policy ACCEPT)
target     prot opt source               destination
ACCEPT     all  --  anywhere             anywhere             ctstate RELATED,ESTABLISHED
ACCEPT     all  --  anywhere             anywhere
FORWARD_direct  all  --  anywhere             anywhere
FORWARD_IN_ZONES_SOURCE  all  --  anywhere             anywhere
FORWARD_IN_ZONES  all  --  anywhere             anywhere
FORWARD_OUT_ZONES_SOURCE  all  --  anywhere             anywhere
FORWARD_OUT_ZONES  all  --  anywhere             anywhere
ACCEPT     icmp --  anywhere             anywhere
REJECT     all  --  anywhere             anywhere             reject-with icmp-host-prohibited

Chain OUTPUT (policy ACCEPT)
target     prot opt source               destination
OUTPUT_direct  all  --  anywhere             anywhere

Chain FORWARD_IN_ZONES (1 references)
target     prot opt source               destination
FWDI_internal  all  --  anywhere             anywhere            [goto]
FWDI_internal  all  --  anywhere             anywhere            [goto]

Chain FORWARD_IN_ZONES_SOURCE (1 references)
target     prot opt source               destination

Chain FORWARD_OUT_ZONES (1 references)
target     prot opt source               destination
FWDO_internal  all  --  anywhere             anywhere            [goto]
FWDO_internal  all  --  anywhere             anywhere            [goto]

Chain FORWARD_OUT_ZONES_SOURCE (1 references)
target     prot opt source               destination

Chain FORWARD_direct (1 references)
target     prot opt source               destination

Chain FWDI_internal (2 references)
target     prot opt source               destination
FWDI_internal_log  all  --  anywhere             anywhere
FWDI_internal_deny  all  --  anywhere             anywhere
FWDI_internal_allow  all  --  anywhere             anywhere

Chain FWDI_internal_allow (1 references)
target     prot opt source               destination

Chain FWDI_internal_deny (1 references)
target     prot opt source               destination

Chain FWDI_internal_log (1 references)
target     prot opt source               destination

Chain FWDO_internal (2 references)
target     prot opt source               destination
FWDO_internal_log  all  --  anywhere             anywhere
FWDO_internal_deny  all  --  anywhere             anywhere
FWDO_internal_allow  all  --  anywhere             anywhere

Chain FWDO_internal_allow (1 references)
target     prot opt source               destination

Chain FWDO_internal_deny (1 references)
target     prot opt source               destination

Chain FWDO_internal_log (1 references)
target     prot opt source               destination

Chain INPUT_ZONES (1 references)
target     prot opt source               destination
IN_internal  all  --  anywhere             anywhere            [goto]
IN_internal  all  --  anywhere             anywhere            [goto]

Chain INPUT_ZONES_SOURCE (1 references)
target     prot opt source               destination

Chain INPUT_direct (1 references)
target     prot opt source               destination

Chain IN_internal (2 references)
target     prot opt source               destination
IN_internal_log  all  --  anywhere             anywhere
IN_internal_deny  all  --  anywhere             anywhere
IN_internal_allow  all  --  anywhere             anywhere

Chain IN_internal_allow (1 references)
target     prot opt source               destination
ACCEPT     udp  --  anywhere             224.0.0.251          udp dpt:mdns ctstate NEW
ACCEPT     tcp  --  anywhere             anywhere             tcp dpt:http ctstate NEW
ACCEPT     udp  --  anywhere             anywhere             udp dpt:ipp ctstate NEW
ACCEPT     tcp  --  anywhere             anywhere             tcp dpt:ssh ctstate NEW
ACCEPT     udp  --  anywhere             anywhere             udp dpt:netbios-ns ctstate NEW
ACCEPT     udp  --  anywhere             anywhere             udp dpt:netbios-dgm ctstate NEW

Chain IN_internal_deny (1 references)
target     prot opt source               destination

Chain IN_internal_log (1 references)
target     prot opt source               destination

Chain OUTPUT_direct (1 references)
target     prot opt source               destination

답변4

http와 같은 특정 포트나 서비스를 허용하려면 방화벽을 사용해야 할 수도 있습니다.

sudo firewall-cmd --permanent --add-service=http && firewall-cmd --reload

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