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named/bind 在自行解析某些域名后拒绝为其提供服务

tag-icon • tag-icon bind internal-dns dns-zone dns-hosting named-conf
named/bind 在自行解析某些域名后拒绝为其提供服务

为什么 bind 拒绝了我的某些查询？这种情况仅发生在某些域中。

通过命名的查询失败：

$ dig -t A fedoraproject.org @127.0.0.1
;; ->>HEADER<<- opcode: QUERY, status: SERVFAIL, id: 33117

$ journalctl -n10
...
Aug 01 17:07:11 ns3.r3.mclarkdev.com named[10807]: resolver priming query complete
Aug 01 17:09:57 ns3.r3.mclarkdev.com named[10807]: timed out resolving 'fedoraproject.org/DNSKEY/IN': 8.8.8.8#53
Aug 01 17:09:59 ns3.r3.mclarkdev.com named[10807]: timed out resolving 'fedoraproject.org/DNSKEY/IN': 8.8.8.8#53

但是直接查询转发器是可行的：

$ dig -t A fedoraproject.org @8.8.8.8
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 42249

  ... records ...

Bind 使用非常默认的配置。
我唯一更改的是允许从任何地方进行查询，并添加区域文件以提供一些本地记录。

options {
    listen-on port 53 { any; };
    allow-query     { any; };
    forwarders      { 8.8.8.8; };
    recursion yes;
    ...
    dnssec-enable yes;
    dnssec-validation yes; // also tried auto
}

...

// includes two additional `zone` definitions
include "/opt/dns/named.zones";

操作系统版本：CentOS Linux 版本 8.4.2105
内核版本：4.18.0-305.10.2.el8_4.x86_64
命名版本：BIND 9.11.26-RedHat-9.11.26-4.el8_4

观看tcpdump，我可以看到 named 正在联系转发器并检索 A 记录，但是在进行了一些额外查询后拒绝将它们提供给客户端。

localhost.49683 > localhost.domain: 14274+ A? fedoraproject.org. (35)
ns3.r3.mclarkdev.com.56668 > 8.8.8.8.domain: 21852+% [1au] A? fedoraproject.org. (58)
localhost.39587 > localhost.domain: 53253+ PTR? 8.8.8.8.in-addr.arpa. (38)
ns3.r3.mclarkdev.com.55378 > 8.8.8.8.domain: 61019+% [1au] PTR? 8.8.8.8.in-addr.arpa. (61)
8.8.8.8.domain > ns3.r3.mclarkdev.com.56668: 21852$ 12/0/1 fedoraproject.org. A 140.211.169.206, fedoraproject.org. A 152.19.134.198, fedoraproject.org. A 8.43.85.73, fedoraproject.org. A 152.19.134.142, fedoraproject.org. A 38.145.60.21, fedoraproject.org. A 140.211.169.196, fedoraproject.org. A 209.132.190.2, fedoraproject.org. A 8.43.85.67, fedoraproject.org. A 67.219.144.68, fedoraproject.org. A 38.145.60.20, fedoraproject.org. RRSIG, fedoraproject.org. RRSIG (528)
  /\ bind has the A records

ns3.r3.mclarkdev.com.52120 > 8.8.8.8.domain: 7073+% [1au] DNSKEY? fedoraproject.org. (58)
8.8.8.8.domain > ns3.r3.mclarkdev.com.55378: 61019 1/0/1 8.8.8.8.in-addr.arpa. PTR dns.google. (73)
ns3.r3.mclarkdev.com.55309 > 8.8.8.8.domain: 23607+% [1au] DS? 8.in-addr.arpa. (55)
localhost.48388 > localhost.domain: 55328+ PTR? 201.23.16.172.in-addr.arpa. (44)
  /\ bind makes some extra queries

localhost.domain > localhost.48388: 55328 NXDomain* 0/1/0 (98)
  /\ bind serves NXDomain to client

为什么 named 拒绝向客户端提供结果？这种情况仅发生在约 1% 的域中。

答案1

tcpdump 显示它已成功获取A的记录fedoraproject.org，但它还尝试获取DNSKEY用于 DNSSEC 验证的 记录。但是没有对此做出任何回应。

我查询8.8.8.8了该DNSKEY记录，并且运行正常。

$ dig fedoraproject.org dnskey @8.8.8.8

; <<>> DiG 9.10.6 <<>> fedoraproject.org dnskey @8.8.8.8
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 63666
;; flags: qr rd ra ad; QUERY: 1, ANSWER: 4, AUTHORITY: 0, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 512
;; QUESTION SECTION:
;fedoraproject.org.     IN  DNSKEY

;; ANSWER SECTION:
fedoraproject.org.  108 IN  DNSKEY  256 3 5 AwEAAcCWNQWl5pCI3iOOP2r8nStL60Zjb/2JQLQytamVap0L44z0YWft u7pu0hx3cnIM1ejQOsEwbg2/10IyC+38cYqJDXbSdFg1zGztOS5xNz7r 9hzSRK5N2jkycdJ/BoByJ4Y+XGpDqfG4I97++8sIzSrw60TmGAKTvM9v iL3ByeCN
fedoraproject.org.  108 IN  DNSKEY  257 3 5 AwEAAdTXJc0joiKGfTvLXi+LXxGpKvPvOoJEst9PR8TCCvXGVp7h3BY3 uXLkjckuT0aopCp2KF8zHgNgpMK03p1fd94pn9JZSuxfqvKsiYH2KvNO a/655oPj06jRhqAP5grX01Iz4BH411ZhGxIQ1BzZtOr1wAazojMJzLUg ChRJs8GVt3LU0e6T8z1RQF33Dt9UMHIR5EAsFAqfZ/tsbfJDYktGoZi3 nFlW7A745+ObM1LNXOWq3FcYPVzhH08Q7/7WpxmzM6/ET8VeqWIsvh8E nZNDNMfJyPbY9B1BOIrFCpE03ALgFMejaBZwmeQaX+D4Duup5xGOmdtC O4GSpM1YH6c=
fedoraproject.org.  108 IN  DNSKEY  257 3 14 7ttmhus8JD56ybsvMVZVsXa3U2R+2+WmOPIP7BU6t2LicosMZ2Ju3pfv ijsa5LvBvVCB4xVtLSqEdLSvW4vJPLSAB2uyJwHPJMezh0SzGmVCImLU 6qDxsxjHqtZ76/Sf
fedoraproject.org.  108 IN  DNSKEY  256 3 14 04ZsDOgyzs3kJsJ4jEY3MYufkCOWm1OI8N4M+dlBOBmweln0TSaKfafH zNCkaPiVG4bdgdnrzwxmjpK5GQgsiB47np+I8850Ea3EJG5ORDl3f//l rr92HiYh5DxCNhkG

所以我怀疑你的环境中有什么东西阻碍了查询或响应。这可能是防火墙问题、过滤 DNS 记录类型或大型响应。

答案2

您的 bind 安装似乎无法对 DNSSEC 签名域进行 DNSSEC 验证。较新版本的 bind 默认启用了 DNSSEC 验证，但旧版本（例如 9.11）需要明确启用它：

options {
         ...
         dnssec-validation auto;
         ...
 };

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