Ipv6

除非指定 +trace,否則 ipv6 反向 dns 不起作用

  • October 20, 2014

我正在嘗試在我的區域網路中為 ipv6 設置反向 dns。應委派的 dns 伺服器位於 2001:5c0:1400:b::9,RDNS 應為其工作的主機位於 2001:5c0:1500:300::1。問題是,除非指定 +trace,否則 dig -x 似乎不起作用:

$ dig -x 2001:5c0:1500:300::1

; <<>> DiG 9.9.5-3-Ubuntu <<>> -x 2001:5c0:1500:300::1
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: SERVFAIL, id: 24545
;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 4096
;; QUESTION SECTION:
;1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.3.0.0.0.5.1.0.c.5.0.1.0.0.2.ip6.arpa. IN PTR

;; Query time: 714 msec
;; SERVER: 192.168.0.1#53(192.168.0.1)
;; WHEN: Sun Oct 19 23:31:58 CEST 2014
;; MSG SIZE  rcvd: 101


$ dig -x 2001:5c0:1500:300::1 +trace

; <<>> DiG 9.9.5-3-Ubuntu <<>> -x 2001:5c0:1500:300::1 +trace                                                                                      
;; global options: +cmd                                                                                                                            
.                       433182  IN      NS      l.root-servers.net.                                                                                
.                       433182  IN      NS      a.root-servers.net.                                                                                
.                       433182  IN      NS      f.root-servers.net.
.                       433182  IN      NS      c.root-servers.net.
.                       433182  IN      NS      h.root-servers.net.
.                       433182  IN      NS      i.root-servers.net.
.                       433182  IN      NS      g.root-servers.net.
.                       433182  IN      NS      e.root-servers.net.
.                       433182  IN      NS      b.root-servers.net.
.                       433182  IN      NS      j.root-servers.net.
.                       433182  IN      NS      k.root-servers.net.
.                       433182  IN      NS      d.root-servers.net.
.                       433182  IN      NS      m.root-servers.net.
.                       435889  IN      RRSIG   NS 8 0 518400 20141025170000 20141018160000 22603 . kvgfN/rC3esMrbGF3KZFrwogm1EKA+nwZrFMXHf3a9sJsDZdpe4iDrOB 0xKyu9dvcsdfLcVLDMHGojlQqUAOda9KIcOGIdeFXl3IOKAk91XvQfrq mLOz02vrBog6gfFnzA34lGkLan1BtRFqKkjxvIHUyIcxstZkak44p/2/ t1w=
;; Received 913 bytes from 192.168.0.1#53(192.168.0.1) in 369 ms

ip6.arpa.               172800  IN      NS      d.ip6-servers.arpa.
ip6.arpa.               172800  IN      NS      b.ip6-servers.arpa.
ip6.arpa.               172800  IN      NS      c.ip6-servers.arpa.
ip6.arpa.               172800  IN      NS      e.ip6-servers.arpa.
ip6.arpa.               172800  IN      NS      f.ip6-servers.arpa.
ip6.arpa.               172800  IN      NS      a.ip6-servers.arpa.
ip6.arpa.               86400   IN      DS      13880 8 2 068554EFCB5861F42AF93EF8E79C442A86C16FC5652E6B6D2419ED52 7F344D17
ip6.arpa.               86400   IN      RRSIG   DS 8 2 86400 20141026190000 20141019180000 10069 arpa. oRqujHjYlEPu3LNM61WtGMXvMyXYYxvBnTPxYLhZxs3rZxqLNaqmzMQr 5cGjUBoEPbAQSsSvpXBX/VHKRf0FjcpL1kXt6YcmzwMyMKdlQrC9Rrxz AQd1csbsfpJP6E6AwWz3Vbd/AnsghIk+BRKerC2+DxjCxU8UpV9ae/3v R0o=
;; Received 685 bytes from 192.33.4.12#53(c.root-servers.net) in 77 ms

1.0.c.5.0.1.0.0.2.ip6.arpa. 86400 IN    NS      ns2.gogo6.com.
1.0.c.5.0.1.0.0.2.ip6.arpa. 86400 IN    NS      ns1.gogo6.com.
1.0.c.5.0.1.0.0.2.ip6.arpa. 10800 IN    NSEC    8.c.5.0.1.0.0.2.ip6.arpa. NS RRSIG NSEC
1.0.c.5.0.1.0.0.2.ip6.arpa. 10800 IN    RRSIG   NSEC 5 11 10800 20141102202721 20141019192721 49851 5.0.1.0.0.2.ip6.arpa. GVMC0TF/hNZGCCRXY4bvpvuyqtmqC5mqhVp0DGhxldJ0m64CVzmOcFMf S3aqoggYRPMYqHNKG4Zjg40/IlwXSdsLmTmOQgBu0OBR4tJBGuomqoTP 7BsXeKx0a3Vgz/8mdz1Nf8e4czGWwkCAo/AomluyWKdEDM5bQiX30Uqa e0k=
;; Received 372 bytes from 2001:dc0:2001:a:4608::59#53(e.ip6-servers.arpa) in 373 ms

3.0.0.0.5.1.0.c.5.0.1.0.0.2.ip6.arpa. 3600 IN NS wonderland.broker.freenet6.net.
;; Received 173 bytes from 72.55.143.215#53(ns1.gogo6.com) in 125 ms

1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.3.0.0.0.5.1.0.c.5.0.1.0.0.2.ip6.arpa. 3600 IN PTR wonderland.broker.freenet6.net.
;; Received 128 bytes from 2001:5c0:1400:b::9#53(wonderland.broker.freenet6.net) in 0 ms

我還嘗試了http://www.sput.nl/internet/ipv6/chkip6rev.html之類的線上工具,他們確實報告了 SERVFAIL。我等了一天,看看這是否是一些記憶體的影響,但問題仍然存在。這裡可能發生了什麼?

此委託中的某些 DNS 解析器將失敗:

3.0.0.0.5.1.0.c.5.0.1.0.0.2.ip6.arpa. 3600 IN NS wonderland.broker.freenet6.net.

DNS 伺服器wonderland.broker.freenet6.net只有一個 IPv6 地址:

$ host wonderland.broker.freenet6.net
wonderland.broker.freenet6.net has IPv6 address 2001:5c0:1400:b::9

當您這樣做時dig,您要求您配置的 DNS 解析器為您解析地址。如果該解析器沒有 IPv6,那麼它將無法遵循此委託,因為它無法訪問僅限 IPv6 的 DNS 伺服器。當你這樣做時,你dig +trace會自己解決所有問題。如果您的系統有 IPv6,那麼它可以遵循整個鏈。在沒有 IPv6 的系統上,解析也會失敗。

在這種情況下,問題(也是?)似乎與權威 DNS 伺服器中的錯誤有關2001:5c0:1400:b::9。它發送的答案不符合 DNS 標準。根據RFC 1034,原始問題必須包含在響應中。但是,您的 DNS 伺服器會發送一個空的問題部分(BIND 報告為“問題太多”,儘管從技術上講它是“問題不足”,!= 1我猜是匹配的):

Domain Name System (response)
 Transaction ID: 0xad20
 Flags: 0x8400 Standard query response, No error
 Questions: 0
 Answer RRs: 1
 Authority RRs: 0
 Additional RRs: 0
 Answers
   1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.3.0.0.0.5.1.0.c.5.0.1.0.0.2.ip6.arpa:
                          type PTR, class IN, wonderland.broker.freenet6.net

所以基本上你的權威 DNS 伺服器壞了,dig不在乎,但“真正的”DNS 解析器會……

引用自:https://serverfault.com/questions/638173