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环境和目标

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环境和目标

环境和目标

在我的测试 KVM 实验室中，我有一个虚拟网络172.16.50/24，在这个网络中我有 2 个运行 Bind 9 和 ISC DHCP 服务器的 Centos 7 VM：

  • DNS 主服务器:controller.wsvirt.home (172.16.50.2)
  • 从属 DNS：controller2.wsvirt.home (172.16.50.3)

网络中的所有客户端都是 Linux VM，它们都从 DHCP 服务器获取网络配置。该服务器动态更新 DNS 区域。

Bind 9 是区域的权威服务器wsvirt.home。

在实验室环境中，我测试了必须在我们的商务办公网络中实施的场景。在业务环境中，我应该创建一个 AD 域来为 Windows 客户端提供服务，为此，我们决定使用 Samba 4 作为 DC。我已经为 Centos 7 构建了一个 Samba 服务器，并从源代码中支持 Heimdal Kerberos。

对于 AD，我分配了子网172.16.50.192/26并指定了ad.wsvirt.home域。

AD DC 是运行 Samba 4、Bind 9 和 ISC DHCP 服务器的 Centos 7 VM。Samba 使用 BIND_DLZ 作为 DNS 后端。AD 控制器具有addc1.ad.wsvirt.home域名和IP 172.16.50.193。

所有 Windows AD 客户端都从在 AD DC 上运行的 DHCP 服务器获取 IP，该服务器动态更新绑定 DLZ 区域。

在实际工作的物理环境中，来自两个网络的所有客户端PC都应连接到一个广播域。

为了满足要求，我将正向ad.wsvirt.home和反向172.16.50.192/26DNS 区域的权限从服务器上的 Bind 委托controller.wsvirt.home给 AD 控制器，addc1.ad.wsvirt.home以便RFC 2317。


＃ 问题 ＃

除了一件事之外，一切都运行正常。当我通过 AD DC 测试委派反向区域的反向查找时，结果看起来不错，因此 Windows AD 客户端可以解析两个域中的所有反向域名。：

$ dig -x 172.16.50.193 @addc1.ad.wsvirt.home

; <<>> DiG 9.11.4-P2-RedHat-9.11.4-9.P2.el7 <<>> -x 172.16.50.193 @addc1.ad.wsvirt.home
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 43507
;; flags: qr rd ra; QUERY: 1, ANSWER: 2, AUTHORITY: 0, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 4096
;; QUESTION SECTION:
;193.50.16.172.in-addr.arpa.    IN      PTR

;; ANSWER SECTION:
193.50.16.172.in-addr.arpa. 86400 IN    CNAME   193.50.16.172.ddns.
193.50.16.172.ddns.     900     IN      PTR     addc1.ad.wsvirt.home.

;; Query time: 7 msec
;; SERVER: 172.16.50.193#53(172.16.50.193)
;; WHEN: Mon Mar 30 21:05:12 IDT 2020
;; MSG SIZE  rcvd: 121

但是，当我将请求路由到 DNS 服务器时，controller.wsvirt.home它不会解析域中的任何反向名称ad.wsvirt.home，因此 Linux 客户端也无法查找任何反向名称：

$ dig -x 172.16.50.193 @controller.wsvirt.home

; <<>> DiG 9.11.4-P2-RedHat-9.11.4-9.P2.el7 <<>> -x 172.16.50.193 @controller.wsvirt.home
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NXDOMAIN, id: 48825
;; flags: qr aa rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 1, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 4096
;; QUESTION SECTION:
;193.50.16.172.in-addr.arpa.    IN      PTR

;; ANSWER SECTION:
193.50.16.172.in-addr.arpa. 86400 IN    CNAME   193.50.16.172.ddns.

;; AUTHORITY SECTION:
.                       8133    IN      SOA     a.root-servers.net. nstld.verisign-grs.com. 2020033001 1800 900 604800 86400

;; Query time: 0 msec
;; SERVER: 172.16.50.2#53(172.16.50.2)
;; WHEN: Mon Mar 30 21:49:41 IDT 2020
;; MSG SIZE  rcvd: 162

我需要域中的 Linux 客户端wsvirt.home能够解析域中的反向域名ad.wsvirt.home。这可能吗？


配置

为了更准确，我在这里放了两个服务器的配置文件

服务器控制器.wsvirt.home

/etc/named.conf

acl local { 172.16.50.0/24; 127.0.0.1; };

include "/etc/named.rfc1912.zones";
include "/etc/named.root.key";
include "/etc/rndc.key";

server 172.16.50.3 {
        keys { "rndc-key"; };
};

...

options {
        listen-on port 53 { local; };
        listen-on-v6 port 53 { ::1; };
        directory       "/var/named";
        dump-file       "/var/named/data/cache_dump.db";
        statistics-file "/var/named/data/named_stats.txt";
        memstatistics-file "/var/named/data/named_mem_stats.txt";
        recursing-file  "/var/named/data/named.recursing";
        secroots-file   "/var/named/data/named.secroots";
        allow-query     { local; };
        allow-transfer { none; };
        notify no; 
        forwarders { 8.8.8.8; 8.8.4.4; };
        forward only;
        recursion yes;
        dnssec-enable yes;
        dnssec-validation yes;
        bindkeys-file "/etc/named.iscdlv.key";
        managed-keys-directory "/var/named/dynamic";
        pid-file "/run/named/named.pid";
        session-keyfile "/run/named/session.key";
};


zone "." IN {
        type hint; 
        file "named.ca";
};

zone "wsvirt.home" IN {
        type master;
        file "wsvirt.home.db";
        allow-update { key "rndc-key"; };
        allow-transfer { key "rndc-key"; };
        notify yes;
        forwarders {};
};

zone "50.16.172.in-addr.arpa" IN {
        type master;
        file "50.16.172.db";
        allow-update { key "rndc-key"; };
        allow-transfer { key "rndc-key"; };
        notify yes;
};

/var/named/50.16.172.db

$ORIGIN .
$TTL 86400      ; 1 day
50.16.172.in-addr.arpa  IN SOA  controller.wsvirt.home. root.wsvirt.home. (
                                153        ; serial
                                3600       ; refresh (1 hour)
                                1800       ; retry (30 minutes)
                                604800     ; expire (1 week)
                                86400      ; minimum (1 day)
                                )
                        NS      controller.wsvirt.home.
                        NS      controller2.wsvirt.home.
$ORIGIN 50.16.172.in-addr.arpa.
2                       PTR     controller.wsvirt.home.
$TTL 86400      ; 1 day
3                       PTR     controller2.wsvirt.home.
...
;
50.16.172.ddns.         IN      NS      addc1.ad.wsvirt.home.
$GENERATE 193-254 $     IN      CNAME   $.50.16.172.ddns.

/etc/dhcp/dhcpd.conf

include "/etc/rndc.key";

default-lease-time 600;
max-lease-time 7200;
authoritative;
ddns-update-style interim;

class "windows" {  
        match if substring (option vendor-class-identifier, 0, 8) = "MSFT 5.0";
}

subnet 172.16.50.0 netmask 255.255.255.0 {
        log (info, concat("Vendor Class ID (60): ", option vendor-class-identifier));
        log (info, concat("DHCP Client ID (61): ", option dhcp-client-identifier));
        log (info, concat("User Class ID (77): ", option user-class));
        option domain-name-servers 172.16.50.2, 172.16.50.3;
        option ntp-servers 172.16.50.2;
        option routers 172.16.50.1;
        option broadcast-address 172.16.50.255;
        default-lease-time 600;
        max-lease-time 7200;
        option ip-forwarding off;
        ignore client-updates;
        option domain-name "wsvirt.home";
        option domain-search "wsvirt.home";
        option netbios-scope "";
        option netbios-node-type 8;
        option netbios-name-servers 172.16.50.2;
        option netbios-dd-server 172.16.50.2;
        ddns-updates on;
        ddns-domainname "wsvirt.home.";
        ddns-rev-domainname "in-addr.arpa.";

        pool {  
                range 172.16.50.21 172.16.50.190;
                deny members of "windows";
        }

        zone wsvirt.home {
                primary 172.16.50.2;
                key "rndc-key";
        }

        zone 50.16.172.in-addr.arpa {
                primary 172.16.50.2;
                key "rndc-key";
        }
}

广告 DC addc1.ad.wsvirt.home

/etc/named.conf

options {
    listen-on port 53 { any; };
    listen-on-v6 port 53 { ::1; };
    directory   "/var/named";
    dump-file   "/var/named/data/cache_dump.db";
    statistics-file "/var/named/data/named_stats.txt";
    memstatistics-file "/var/named/data/named_mem_stats.txt";
    recursing-file  "/var/named/data/named.recursing";
    secroots-file   "/var/named/data/named.secroots";
    allow-query     { any; };
    forwarders  { 172.16.50.2; 172.16.50.3; };
    forward only;
    recursion yes;
    dnssec-enable no;
    dnssec-validation no;
    bindkeys-file "/etc/named.root.key";
    managed-keys-directory "/var/named/dynamic";
    pid-file "/run/named/named.pid";
    session-keyfile "/run/named/session.key";
    tkey-gssapi-keytab "/var/lib/samba/private/dns.keytab";
    minimal-responses yes;
};

...

zone "." IN {
    type hint;
    file "named.ca";
};

include "/etc/rndc.key";
include "/etc/named.rfc1912.zones";
include "/etc/named.root.key";
include "/var/lib/samba/bind-dns/named.conf";

/etc/dhcp/dhcpd.conf

include "/etc/rndc.key";

default-lease-time 600;
max-lease-time 7200;
min-secs 5;
authoritative;
ddns-update-style none;

class "others" {
    match if substring (option vendor-class-identifier, 0, 8) != "MSFT 5.0";
}

subnet 172.16.50.192 netmask 255.255.255.192 {
    log (info, concat("Vendor Class ID (60): ", option vendor-class-identifier));
    log (info, concat("DHCP Client ID (61): ", option dhcp-client-identifier));
    log (info, concat("User Class ID (77): ", option user-class));
    option routers 172.16.50.1;
    option broadcast-address 172.16.50.255;
    default-lease-time 600;
    max-lease-time 7200;
    option ip-forwarding off;
    ignore client-updates;
    option ntp-servers 172.16.50.193;
    option domain-name-servers 172.16.50.193;
    option domain-name "ad.wsvirt.home";
    option domain-search "ad.wsvirt.home";
    option netbios-name-servers 172.16.50.193;
    option netbios-dd-server 172.16.50.193;
    option netbios-scope "";
    option netbios-node-type 8;
    ddns-rev-domainname "ddns";

    pool {
        range 172.16.50.210 172.16.50.254;
        deny members of "others";
    }
}

on commit {
    set noname = concat("dhcp-", binary-to-ascii(10, 8, "-", leased-address));
    set ClientIP = binary-to-ascii(10, 8, ".", leased-address);
    set ClientDHCID = concat (
    suffix (concat ("0", binary-to-ascii (16, 8, "", substring(hardware,1,1))),2), ":",
    suffix (concat ("0", binary-to-ascii (16, 8, "", substring(hardware,2,1))),2), ":",
    suffix (concat ("0", binary-to-ascii (16, 8, "", substring(hardware,3,1))),2), ":",
    suffix (concat ("0", binary-to-ascii (16, 8, "", substring(hardware,4,1))),2), ":",
    suffix (concat ("0", binary-to-ascii (16, 8, "", substring(hardware,5,1))),2), ":",
    suffix (concat ("0", binary-to-ascii (16, 8, "", substring(hardware,6,1))),2)
    );
    set ClientName = pick-first-value(option host-name, config-option-host-name, client-name, noname);
    log(concat("Commit: IP: ", ClientIP, " DHCID: ", ClientDHCID, " Name: ", ClientName));
    execute("/usr/local/sbin/dhcp-dyndns.sh", "add", ClientIP, ClientDHCID, ClientName);
}

on release {  
    set ClientIP = binary-to-ascii(10, 8, ".", leased-address);
    set ClientDHCID = concat (
    suffix (concat ("0", binary-to-ascii (16, 8, "", substring(hardware,1,1))),2), ":",
    suffix (concat ("0", binary-to-ascii (16, 8, "", substring(hardware,2,1))),2), ":",
    suffix (concat ("0", binary-to-ascii (16, 8, "", substring(hardware,3,1))),2), ":",
    suffix (concat ("0", binary-to-ascii (16, 8, "", substring(hardware,4,1))),2), ":",
    suffix (concat ("0", binary-to-ascii (16, 8, "", substring(hardware,5,1))),2), ":",
    suffix (concat ("0", binary-to-ascii (16, 8, "", substring(hardware,6,1))),2)
    );
    log(concat("Release: IP: ", ClientIP));
    execute("/usr/local/sbin/dhcp-dyndns.sh", "delete", ClientIP, ClientDHCID);
}

on expiry {   
    set ClientIP = binary-to-ascii(10, 8, ".", leased-address);
    log(concat("Expired: IP: ", ClientIP));
    execute("/usr/local/sbin/dhcp-dyndns.sh", "delete", ClientIP, "", "0");
}

AD DC 上的 DLZ 反向区域 50.16.172.ddns

$ samba-tool dns query localhost 50.16.172.ddns @ ALL 
Password for [[email protected]]:
  Name=, Records=2, Children=0
    SOA: serial=3, refresh=900, retry=600, expire=86400, minttl=3600, ns=addc1.ad.wsvirt.home., email=hostmaster.ad.wsvirt.home. (flags=600000f0, serial=3, ttl=3600)
    NS: addc1.ad.wsvirt.home. (flags=600000f0, serial=1, ttl=3600)
  Name=193, Records=1, Children=0
    PTR: addc1.ad.wsvirt.home (flags=f0, serial=3, ttl=900)
  Name=230, Records=1, Children=0
    PTR: winxp-1.ad.wsvirt.home (flags=f0, serial=3, ttl=3600)

答案1

得到不PTR一样的答案是正常的，因为controller.wsvirt.home.不是一个权威性这两个区域的名称服务器。flags: aa称这是权威答案，但对 来说并非如此193.50.16.172.ddns. IN PTR。因此，无法发送此权威答案。

这实际上不是一个问题，因为这只会导致对 的另一次查询193.50.16.172.ddns. IN PTR，然后可以递归地回答。客户端应该知道在有CNAME答案的情况下自动执行此操作。

关于这一点，另一个问题，因为只有addc1.ad.wsvirt.home.区域50.16.172.ddns.；你会得到NXDOMAIN答案：

dig 193.50.16.172.ddns. PTR @controller.wsvirt.home

被controller.wsvirt.home.配置为递归 ( recursion yes;)，但它不知道这些地址可以在 上找到addc1.ad.wsvirt.home.。因此，它尝试将它们解析为其他所有内容：来自forwarders { 8.8.8.8; 8.8.4.4; };... 并失败。

您可以将 添加为addc1.ad.wsvirt.home.的转发器：50.16.172.ddns.controller.wsvirt.home.

zone "50.16.172.ddns." { 
    type forward; 
    forwarders { 172.16.50.193; }; 
};

最后， 的区域$ORIGIN 50.16.172.in-addr.arpa.只能委托对其自己的子域的控制，而不能委托对完全不相关的 的控制50.16.172.ddns.。

如果您确实仍想发送PTR相同的响应，则需要50.16.172.ddns.通过添加slave区域（而不是区域forward）使该域具有权威性，例如

zone "50.16.172.ddns." { 
    type slave;
    file "50.16.172.ddns.db";
    masters { 172.16.50.193; }; 
};

主服务器（addc1.ad.wsvirt.home.）需要意识到这一点，并允许从 进行区域传输controller.wsvirt.home.（并且controller2.wsvirt.home，如果它应该采取类似行动）：

options {
    . . .
    allow-transfer { 172.16.50.2; 172.16.50.3; };
}

答案2

如果您要使用我的脚本，请正确使用它;-)

在 DC 上运行 Bind9 和 isc-dhcp，而不是在其他地方。请参见此处：

https://wiki.samba.org/index.php/Setting_up_a_BIND_DNS_Server

https://wiki.samba.org/index.php/Configure_DHCP_to_update_DNS_records_with_BIND9

您的主要问题之一是您尝试将反向区域存储在“平面文件”中，而 bind9_dlz 不适用于平面文件。

答案3

根据 Esa Jokinen 的建议我做了以下事情：

在控制器.wsvirt.home在/etc/named.conf我为 创建了一个区域部分50.16.172.ddns。

zone "50.16.172.ddns." { 
    type slave;
    file "slaves/50.16.172.ddns.db";
    masters { 172.16.50.193; }; 
};

在区域文件中，/var/named/50.16.172.db我注释掉了委派区域的行50.16.172.ddns：

;50.16.172.ddns.                IN      NS      addc1.ad.wsvirt.home.
;$GENERATE 193-254 $    IN      CNAME   $.50.16.172.ddns.

在添加 c1.ad.wsvirt.home。在里面/etc/named.conf：

options {
    . . .
    allow-transfer { 172.16.50.2; 172.16.50.3; };
}


因此，我拥有该区域的权限50.16.172.ddns，但是反向名称根本没有解析：

dig -x 172.16.50.193 @addc1.ad.wsvirt.home

; <<>> DiG 9.11.4-P2-RedHat-9.11.4-9.P2.el7 <<>> -x 172.16.50.193 @addc1.ad.wsvirt.home
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NXDOMAIN, id: 30147
;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 4096
;; QUESTION SECTION:
;193.50.16.172.in-addr.arpa.    IN      PTR

;; AUTHORITY SECTION:
50.16.172.in-addr.arpa. 10800   IN      SOA     controller.wsvirt.home. root.wsvirt.home. 154 3600 1800 604800 86400

;; Query time: 5 msec
;; SERVER: 172.16.50.193#53(172.16.50.193)
;; WHEN: Wed Apr 01 17:20:44 IDT 2020
;; MSG SIZE  rcvd: 118



$ dig -x 172.16.50.193 

; <<>> DiG 9.11.4-P2-RedHat-9.11.4-9.P2.el7 <<>> -x 172.16.50.193
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NXDOMAIN, id: 62725
;; flags: qr aa rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 4096
;; QUESTION SECTION:
;193.50.16.172.in-addr.arpa.    IN      PTR

;; AUTHORITY SECTION:
50.16.172.in-addr.arpa. 86400   IN      SOA     controller.wsvirt.home. root.wsvirt.home. 154 3600 1800 604800 86400

;; Query time: 0 msec
;; SERVER: 172.16.50.2#53(172.16.50.2)
;; WHEN: Wed Apr 01 17:20:56 IDT 2020
;; MSG SIZE  rcvd: 118

答案4

最后，我发现了问题的根源。关键在于，Bind 9 在作为转发器工作时会剥离 DNSSEC 签名。我知道这一点，因此在named.conf服务器上addc1.ad.wsvirt.home我设置了以下选项作为解决方法：

dnssec-enable no; 
dnssec-validation no;


但我忘了在 上做同样的事情controller.wsvirt.home，现在我已经修复了我的疏忽，一切正常。显然， 的区域部分必须50.16.172.ddns位于服务器上的 Bind 配置文件中addc1.ad.wsvirt.home：

zone "50.16.172.ddns." { 
    type forward; 
    forwarders { 172.16.50.193; }; 
};

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