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Arch Linux 解決問題

tag-icon • tag-icon arch-linux dns raspberry-pi systemd-resolved
Arch Linux 解決問題

我有一個運行 Arch 的 Rasberry Pi，我遇到了一些奇怪的解決行為。長話短說，dig可以nslookup解析主機名，，，，curl不能。如果我新增一個主機，那麼該主機的一切正常。wgetpacman/etc/hosts

以下是一些故障排除的輸出：

  1. resolv.conf存在並且可讀：

    $ ls -l /etc/resolv.conf
-rw-r--r-- 1 root root 19 Apr 28 10:45 /etc/resolv.conf

  2. 我有一個名稱伺服器：

    $ cat /etc/resolv.conf
nameserver 8.8.8.8

  3. nslookup作品：

    $ nslookup google.com
Server:         8.8.8.8
Address:        8.8.8.8#53

Non-authoritative answer:
Name:   google.com
Address: 92.87.11.30
Name:   google.com
Address: 92.87.11.54
Name:   google.com
Address: 92.87.11.49
Name:   google.com
Address: 92.87.11.45
...

  4. dig作品：

    $ dig google.com

; <<>> DiG 9.11.0-P3 <<>> google.com
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 20686
;; flags: qr rd ra; QUERY: 1, ANSWER: 16, AUTHORITY: 0, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 512
;; QUESTION SECTION:
;google.com.                    IN      A

;; ANSWER SECTION:
google.com.             299     IN      A       92.87.175.49
google.com.             299     IN      A       92.87.175.50
google.com.             299     IN      A       92.87.175.48
google.com.             299     IN      A       92.87.175.44
google.com.             299     IN      A       92.87.175.42
google.com.             299     IN      A       92.87.175.41
google.com.             299     IN      A       92.87.175.51
google.com.             299     IN      A       92.87.175.36
google.com.             299     IN      A       92.87.175.39
google.com.             299     IN      A       92.87.175.45
google.com.             299     IN      A       92.87.175.37
google.com.             299     IN      A       92.87.175.40
google.com.             299     IN      A       92.87.175.38
google.com.             299     IN      A       92.87.175.47
google.com.             299     IN      A       92.87.175.43
google.com.             299     IN      A       92.87.175.46

;; Query time: 40 msec
;; SERVER: 8.8.8.8#53(8.8.8.8)
;; WHEN: Fri Apr 28 11:37:32 EEST 2017
;; MSG SIZE  rcvd: 295

  5. 我可以使用ping其中一個 IP：

    $ ping 92.87.175.49
PING 92.87.175.49 (92.87.175.49) 56(84) bytes of data.
64 bytes from 92.87.175.49: icmp_seq=1 ttl=54 time=3.75 ms
64 bytes from 92.87.175.49: icmp_seq=2 ttl=54 time=3.71 ms

--- 92.87.175.49 ping statistics ---
2 packets transmitted, 2 received, 0% packet loss, time 1001ms
rtt min/avg/max/mdev = 3.711/3.734/3.758/0.065 ms

  6. wget失敗：

    $ wget https://google.com
--2017-04-28 11:39:31--  https://google.com/
Loaded CA certificate '/etc/ssl/certs/ca-certificates.crt'
Resolving google.com... failed: Name or service not known.
wget: unable to resolve host address 'google.com'

  7. curl失敗：

    $ curl https://google.com
curl: (6) Could not resolve host: google.com

我錯過了什麼？

編輯：

$ cat /etc/hosts
#
# /etc/hosts: static lookup table for host names
#

#<ip-address>   <hostname.domain.org>   <hostname>
127.0.0.1       localhost.localdomain   localhost
::1             localhost.localdomain   localhost

# End of file

$ cat /etc/nsswitch.conf
# Begin /etc/nsswitch.conf

passwd: compat mymachines systemd
group: compat mymachines systemd
shadow: compat

publickey: files

hosts: files mymachines resolve [!UNAVAIL=return] dns myhostname
networks: files

protocols: files
services: files
ethers: files
rpc: files

netgroup: files

# End /etc/nsswitch.conf

看來是跟有什麼關係systemd-resolvd。如果我停止它或resolve [!UNAVAIL=return]從 中刪除/etc/nsswitch.conf，則解析對每個應用程式都可以正常工作，如果我再次啟動它或/etc/nsswitch.conf按原樣保留，則解析僅適用於nslookup& dig。

答案1

archlinuxarm 更新後我遇到了類似的問題：某些網站可以工作，但大多數網站不可用，而且 pacman 無法更新。就我而言，問題是系統解析器上的 dnssec。可以透過從控制台運行來檢測它：

resolvectl 查詢 archlinuxarm.org（或任何其他不可用的站點）

答案是：... DNSSEC 驗證失敗：無效

就我而言，幫助將 DNSSEC=false 新增至 /etc/systemd/resolved.conf 並重新啟動

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