diff --git a/sources/tech/20211204 How to use dig.md b/sources/tech/20211204 How to use dig.md deleted file mode 100644 index 101984aa4d..0000000000 --- a/sources/tech/20211204 How to use dig.md +++ /dev/null @@ -1,279 +0,0 @@ -[#]: subject: "How to use dig" -[#]: via: "https://jvns.ca/blog/2021/12/04/how-to-use-dig/" -[#]: author: "Julia Evans https://jvns.ca/" -[#]: collector: "lujun9972" -[#]: translator: "wxy" -[#]: reviewer: " " -[#]: publisher: " " -[#]: url: " " - -How to use dig -====== - -Hello! I talked to a couple of friends recently who mentioned they wished they knew how to use `dig` to make DNS queries, so here’s a quick blog post about it. - -When I first started using `dig` I found it a bit intimidating – there are so many options! I’m going to leave out most of dig’s options in this post and just talk about the ones I actually use. - -Also I learned recently that you can set up a `.digrc` configuration file to make its output easier to read and it makes it SO MUCH nicer to use. - -I also drew a [zine page about dig][1] a few years ago, but I wanted to write this post to include a bit more information. - -### 2 types of dig arguments: query and formatting - -There are 2 main types of arguments you can pass to `dig`: - - 1. arguments that tell dig **what DNS query to make** - 2. arguments that tell dig how to **format the response** - - - -First, let’s go through the query options. - -### the main query options - -The 3 things you usually want to control about a DNS query are: - - 1. the **name** (like `jvns.ca`). The default is a query for the empty name (`.`). - 2. the **DNS query type** (like `A` or `CNAME`). The default is `A`. - 3. the **server** to send the query to (like `8.8.8.8`). The default is what’s in `/etc/resolv.conf`. - - - -The format for these is: - -``` - - dig @server name type - -``` - -Here are a couple of examples: - - * `dig @8.8.8.8 jvns.ca` queries Google’s public DNS server (`8.8.8.8`) for `jvns.ca`. - * `dig ns jvns.ca` makes an query with type `NS` for `jvns.ca` - - - -### `-x`: make a reverse DNS query - -One other query option I use occasionally is `-x`, to make a reverse DNS query. Here’s what the output looks like. - -``` - - $ dig -x 172.217.13.174 - 174.13.217.172.in-addr.arpa. 72888 IN PTR yul03s04-in-f14.1e100.net. - -``` - -`-x` isn’t magic – `dig -x 172.217.13.174` just makes a `PTR` query for `174.13.217.172.in-addr.arpa.`. Here’s how to make exact the same reverse DNS query without using `-x`. - -``` - - $ dig ptr 174.13.217.172.in-addr.arpa. - 174.13.217.172.in-addr.arpa. 72888 IN PTR yul03s04-in-f14.1e100.net. - -``` - -I always use `-x` though because it’s less typing. - -### options for formatting the response - -Now, let’s talk about arguments you can use to format the response. - -I’ve found that the way `dig` formats DNS responses by default is pretty overwhelming to beginners. Here’s what the output looks like: - -``` - - ; <<>> DiG 9.16.20 <<>> -r jvns.ca - ;; global options: +cmd - ;; Got answer: - ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 28629 - ;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1 - - ;; OPT PSEUDOSECTION: - ; EDNS: version: 0, flags:; udp: 4096 - ; COOKIE: d87fc3022c0604d60100000061ab74857110b908b274494d (good) - ;; QUESTION SECTION: - ;jvns.ca. IN A - - ;; ANSWER SECTION: - jvns.ca. 276 IN A 172.64.80.1 - - ;; Query time: 9 msec - ;; SERVER: 192.168.1.1#53(192.168.1.1) - ;; WHEN: Sat Dec 04 09:00:37 EST 2021 - ;; MSG SIZE rcvd: 80 - -``` - -If you’re not used to reading this, it might take you a while to sift through it and find the IP address you’re looking for. And most of the time, you’re only interested in one line of this response (`jvns.ca. 180 IN A 172.64.80.1`). - -Here are my 2 favourite ways to make dig’s output more manageable. - -**way 1: +noall +answer** - -This tells dig to just print what’s in the “Answer” section of the DNS response. Here’s an example of querying for the `NS` records for `google.com`. - -``` - - $ dig +noall +answer ns google.com - google.com. 158564 IN NS ns4.google.com. - google.com. 158564 IN NS ns1.google.com. - google.com. 158564 IN NS ns2.google.com. - google.com. 158564 IN NS ns3.google.com. - -``` - -The format here is: - -``` - - NAME TTL TYPE CONTENT - google.com 158564 IN NS ns3.google.com. - -``` - -By the way: if you’ve ever wondered what `IN` means, it’s the “query class” and stands for “internet”. It’s basically just a relic from the 80s and 90s when there were other networks competing with the internet like “chaosnet”. - -**way 2: +short** - -This is like `dig +noall +answer`, but even shorter – it just shows the content of each record. For example: - -``` - - $ dig +short ns google.com - ns2.google.com. - ns1.google.com. - ns4.google.com. - ns3.google.com. - -``` - -### you can put formatting options in `digrc` - -If you don’t like dig’s default format (I don’t!), you can tell it to use a different format by default by creating a `.digrc` file in your home directory. - -I really like the `+noall +answer` format, so I put `+noall +answer` in my `~/.digrc`. Here’s what it looks like for me when I run `dig jvns.ca` using that configuration file. - -``` - - $ dig jvns.ca - jvns.ca. 255 IN A 172.64.80.1 - -``` - -So much easier to read! - -And if I want to go back to the long format with all of the output (which I do sometimes, usually because I want to look at the records in the Authority section of the response), I can get a long answer again by running: - -``` - - $ dig +all jvns.ca - -``` - -### dig +trace - -The last dig option that I use is `+trace`. `dig +trace` mimics what a DNS resolver does when it looks up a domain – it starts at the root nameservers, and then queries the next level of nameservers (like `.com`), and so on until it reaches the authoritative nameserver for the domain. So it’ll make about 30 DNS queries. (I checked using tcpdump, it seems to make 2 queries to get A/AAAA records for each of the root nameservers so that’s already 26 queries. I’m not really sure _why_ it does this because it should already have those IPs hardcoded, but it does.) - -I find this mostly useful for understanding how DNS works though, I don’t think that I’ve used it to solve a problem. - -### why dig? - -Even though there are simpler tools to make DNS queries (like `dog` and `host`), I find myself sticking with dig. - -What I like about dig is actually the same thing I **don’t** like about dig – it shows a lot of detail! - -I know that if I run `dig +all`, it’ll show me all of the sections of the DNS response. For example, let’s query one of the root nameservers for `jvns.ca`. The response has 3 sections I might care about – Answer, Authority, and Additional. - -``` - - $ dig @h.root-servers.net. jvns.ca +all - ;; Got answer: - ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 18229 - ;; flags: qr rd; QUERY: 1, ANSWER: 0, AUTHORITY: 4, ADDITIONAL: 9 - ;; WARNING: recursion requested but not available - - ;; OPT PSEUDOSECTION: - ; EDNS: version: 0, flags:; udp: 1232 - ;; QUESTION SECTION: - ;jvns.ca. IN A - - ;; AUTHORITY SECTION: - ca. 172800 IN NS c.ca-servers.ca. - ca. 172800 IN NS j.ca-servers.ca. - ca. 172800 IN NS x.ca-servers.ca. - ca. 172800 IN NS any.ca-servers.ca. - - ;; ADDITIONAL SECTION: - c.ca-servers.ca. 172800 IN A 185.159.196.2 - j.ca-servers.ca. 172800 IN A 198.182.167.1 - x.ca-servers.ca. 172800 IN A 199.253.250.68 - any.ca-servers.ca. 172800 IN A 199.4.144.2 - c.ca-servers.ca. 172800 IN AAAA 2620:10a:8053::2 - j.ca-servers.ca. 172800 IN AAAA 2001:500:83::1 - x.ca-servers.ca. 172800 IN AAAA 2620:10a:80ba::68 - any.ca-servers.ca. 172800 IN AAAA 2001:500:a7::2 - - ;; Query time: 103 msec - ;; SERVER: 198.97.190.53#53(198.97.190.53) - ;; WHEN: Sat Dec 04 11:23:32 EST 2021 - ;; MSG SIZE rcvd: 289 - -``` - -`dog` also shows the records in the “additional” section , but it’s not super explicit about which is which (I guess the `+` means it’s in the additional section?). It doesn’t seem to show the records in the “Authority” section. - -``` - - $ dog @h.root-servers.net. jvns.ca - NS ca. 2d0h00m00s A "c.ca-servers.ca." - NS ca. 2d0h00m00s A "j.ca-servers.ca." - NS ca. 2d0h00m00s A "x.ca-servers.ca." - NS ca. 2d0h00m00s A "any.ca-servers.ca." - A c.ca-servers.ca. 2d0h00m00s + 185.159.196.2 - A j.ca-servers.ca. 2d0h00m00s + 198.182.167.1 - A x.ca-servers.ca. 2d0h00m00s + 199.253.250.68 - A any.ca-servers.ca. 2d0h00m00s + 199.4.144.2 - AAAA c.ca-servers.ca. 2d0h00m00s + 2620:10a:8053::2 - AAAA j.ca-servers.ca. 2d0h00m00s + 2001:500:83::1 - AAAA x.ca-servers.ca. 2d0h00m00s + 2620:10a:80ba::68 - AAAA any.ca-servers.ca. 2d0h00m00s + 2001:500:a7::2 - -``` - -And `host` seems to only show the records in the “answer” section (in this case no records) - -``` - - $ host jvns.ca h.root-servers.net - Using domain server: - Name: h.root-servers.net - Address: 198.97.190.53#53 - Aliases: - -``` - -Anyway, I think that these simpler DNS tools are great (I even made my own [simple web DNS tool][2]) and you should absolutely use them if you find them easier but that’s why I stick with dig. `drill`’s output format seems very similar to `dig`’s though, and maybe `drill` is better! I haven’t really tried it. - -### that’s all! - -I only learned about `.digrc` recently and I love using it so much, so I hope it helps some of you spend less time sorting though dig output! - -Someone on Twitter pointed out that it would be nice if there were a way to tell dig to show a short version of the response which also included the response’s status (like `NOERROR`, `NXDOMAIN`, `SERVFAIL`, etc), and I agree! I couldn’t find an option in the man page that does that though. - --------------------------------------------------------------------------------- - -via: https://jvns.ca/blog/2021/12/04/how-to-use-dig/ - -作者：[Julia Evans][a] -选题：[lujun9972][b] -译者：[译者ID](https://github.com/译者ID) -校对：[校对者ID](https://github.com/校对者ID) - -本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 - -[a]: https://jvns.ca/ -[b]: https://github.com/lujun9972 -[1]: https://wizardzines.com/comics/dig/ -[2]: https://dns-lookup.jvns.ca/ diff --git a/translated/tech/20211204 How to use dig.md b/translated/tech/20211204 How to use dig.md new file mode 100644 index 0000000000..be39c2f1b3 --- /dev/null +++ b/translated/tech/20211204 How to use dig.md @@ -0,0 +1,252 @@ +[#]: subject: "How to use dig" +[#]: via: "https://jvns.ca/blog/2021/12/04/how-to-use-dig/" +[#]: author: "Julia Evans https://jvns.ca/" +[#]: collector: "lujun9972" +[#]: translator: "wxy" +[#]: reviewer: "wxy" +[#]: publisher: " " +[#]: url: " " + +如何使用 dig +====== + +![](https://img.linux.net.cn/data/attachment/album/202112/05/192530gj36ttdwz16azu6w.jpg) + +你好！最近我和几个朋友聊天，他们提到希望知道如何使用 `dig` 来进行 DNS 查询，所以这是一篇关于它的速读博文。 + +当我第一次使用 `dig` 时，我发现它有点吓人 —— 有这么多的选项！我打算把大部分的选项省略。在这篇文章中，我打算不谈 `dig` 的大部分选项，只谈我实际使用的选项。 + +我最近还了解到，你可以设置一个 `.digrc` 配置文件，让它的输出更容易阅读，这让它的使用变得更加轻松。 + +几年前我还画了一个关于 `dig` 的 [zine 页][1]，但我想写这篇文章来包括更多的信息。 + +### 两种类型的 dig 参数：查询和格式化 + +有两种主要的参数可以传递给 `dig`： + + 1. 告诉 `dig` **要进行什么 DNS 查询的参数**。 + 2. 告诉 `dig` 如何 **格式化响应的参数**。 + +首先，让我们看一下查询选项。 + +### 主要的查询选项 + +你通常想控制 DNS 查询的 3 件事是： + + 1. **名称**（如 `jvns.ca`）。默认情况下，查询的是空名称（`.`）。 + 2. **DNS 查询类型**（如 `A` 或 `CNAME`）。默认是 `A`。 + 3. 发送查询的 **服务器**（如 `8.8.8.8`）。默认是 `/etc/resolv.conf` 中的内容。 + +其格式是： + +``` +dig @server name type +``` + +这里有几个例子： + + * `dig @8.8.8.8 jvns.ca` 向谷歌的公共 DNS 服务器（`8.8.8.8`）查询 `jvns.ca`。 + * `dig ns jvns.ca` 对 `jvns.ca` 进行类型为 `NS` 的查询。 + +### `-x`：进行反向 DNS 查询 + +我偶尔使用的另一个查询选项是 `-x`，用于进行反向 DNS 查询。下面是输出结果的样子。 + +``` +$ dig -x 172.217.13.174 +174.13.217.172.in-addr.arpa. 72888 IN PTR yul03s04-in-f14.1e100.net。 +``` + +`-x` 不是魔术。`dig -x 172.217.13.174` 只是对 `174.13.217.172.in-addr.arpa.` 做了一个 `PTR` 查询。下面是如何在不使用 `-x’ 的情况下进行完全相同的反向 DNS 查询。 + +``` +$ dig ptr 174.13.217.172.in-addr.arpa. +174.13.217.172.in-addr.arpa. 72888 IN PTR yul03s04-in-f14.1e100.net。 +``` + +我总是使用 `-x`，因为它可以减少输入。 + +### 格式化响应的选项 + +现在，让我们讨论一下你可以用来格式化响应的参数。 + +我发现 `dig` 默认格式化 DNS 响应的方式对初学者来说是很难接受的。下面是输出结果的样子： + +``` +; <<>> DiG 9.16.20 <<>> -r jvns.ca +;; global options: +cmd +;; Got answer: +;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 28629 +;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1 + +;; OPT PSEUDOSECTION: +; EDNS: version: 0, flags:; udp: 4096 +; COOKIE: d87fc3022c0604d60100000061ab74857110b908b274494d (good) +;; QUESTION SECTION: +;jvns.ca. IN A + +;; ANSWER SECTION: +jvns.ca. 276 IN A 172.64.80.1 + +;; Query time: 9 msec +;; SERVER: 192.168.1.1#53(192.168.1.1) +;; WHEN: Sat Dec 04 09:00:37 EST 2021 +;; MSG SIZE rcvd: 80 +``` + +如果你不习惯看这个，你可能需要花点时间来筛选，找到你要找的 IP 地址。而且大多数时候，你只对这个响应中的一行感兴趣（`jvns.ca. 180 IN A 172.64.80.1`）。 + +下面是我最喜欢的两种方法，可以使 `dig` 的输出更容易管理： + +#### 方式 1 : +noall +answer + +这告诉 `dig` 只打印 DNS 响应中的“答案”部分的内容。下面是一个查询 `google.com` 的 `NS` 记录的例子： + +``` +$ dig +noall +answer ns google.com +google.com. 158564 IN NS ns4.google.com. +google.com. 158564 IN NS ns1.google.com. +google.com. 158564 IN NS ns2.google.com. +google.com. 158564 IN NS ns3.google.com. +``` + +这里的格式是： + +``` +NAME TTL TYPE CONTENT +google.com 158564 IN NS ns3.google.com. +``` + +顺便说一下：如果你曾经想知道 `IN` 是什么意思，它是指“查询类”，代表“互联网 internet”。它基本上只是上世纪 80、90 年代的遗物，当时还有其他网络与互联网竞争，如“混沌网络chaosnet”。 + +#### 方式 2：+short + +这就像 `dig +noall +answer`，但更短：它只显示每条记录的内容。比如说： + +``` +$ dig +short ns google.com +ns2.google.com. +ns1.google.com. +ns4.google.com. +ns3.google.com. +``` + +### 你可以在 `digrc` 中设置格式化选项 + +如果你不喜欢 `dig` 的默认格式（我就不喜欢！），你可以在你的主目录下创建一个 `.digrc` 文件，告诉它默认使用不同的格式。 + +我非常喜欢 `+noall +answer` 格式，所以我把 `+noall +answer` 放在我的 `~/.digrc` 中。下面是我使用该配置文件运行 `dig jvns.ca` 时的情况。 + +``` +$ dig jvns.ca +jvns.ca. 255在172.64.80.1中 +``` + +这样读起来就容易多了！ + +如果我想回到所有输出的长格式（我有时会这样做，通常是因为我想看响应的权威部分的记录），我可以通过运行再次得到一个长答案。 + +``` +$ dig +all jvns.ca +``` + +### dig +trace + +我使用的最后一个 `dig` 选项是 `+trace`。`dig +trace` 模仿 DNS 解析器在查找域名时的做法 —— 它从根域名服务器开始，然后查询下一级域名服务器（如 `.com`），以此类推，直到到达该域名的权威域名服务器。因此，它将进行大约 30 次 DNS 查询。（我用 `tcpdump` 检查了一下，对于每个根域名服务器的 `A` / `AAAA` 记录它似乎要进行 2 次查询，所以这已经是 26 次查询了。我不太清楚它为什么这样做，因为它应该已经有了这些 IP 的硬编码，但它确实如此。） + +我发现这对了解 DNS 的工作原理很有用，但我不认为我用它解决过问题。 + +### 为什么要用 dig + +尽管有一些更简单的工具来进行 DNS 查询（如 `dog` 和 `host`），我发现自己还是坚持使用 `dig`。 + +我喜欢 `dig` 的地方实际上也是我 **不喜欢** `dig` 的地方 —— 它显示了大量的细节！ + +我知道，如果我运行 `dig +all`，它将显示 DNS 响应的所有部分。例如，让我们查询 `jvns.ca` 的一个根名称服务器。响应有 3 个部分，我可能会关心：回答部分、权威部分和附加部分。 + +``` +$ dig @h.root-servers.net. jvns.ca +all +;; Got answer: +;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 18229 +;; flags: qr rd; QUERY: 1, ANSWER: 0, AUTHORITY: 4, ADDITIONAL: 9 +;; WARNING: recursion requested but not available + +;; OPT PSEUDOSECTION: +; EDNS: version: 0, flags:; udp: 1232 +;; QUESTION SECTION: +;jvns.ca. IN A + +;; AUTHORITY SECTION: +ca. 172800 IN NS c.ca-servers.ca. +ca. 172800 IN NS j.ca-servers.ca. +ca. 172800 IN NS x.ca-servers.ca. +ca. 172800 IN NS any.ca-servers.ca. + +;; ADDITIONAL SECTION: +c.ca-servers.ca. 172800 IN A 185.159.196.2 +j.ca-servers.ca. 172800 IN A 198.182.167.1 +x.ca-servers.ca. 172800 IN A 199.253.250.68 +any.ca-servers.ca. 172800 IN A 199.4.144.2 +c.ca-servers.ca. 172800 IN AAAA 2620:10a:8053::2 +j.ca-servers.ca. 172800 IN AAAA 2001:500:83::1 +x.ca-servers.ca. 172800 IN AAAA 2620:10a:80ba::68 +any.ca-servers.ca. 172800 IN AAAA 2001:500:a7::2 + +;; Query time: 103 msec +;; SERVER: 198.97.190.53#53(198.97.190.53) +;; WHEN: Sat Dec 04 11:23:32 EST 2021 +;; MSG SIZE rcvd: 289 + +``` + +`dog` 也显示了 “附加” 部分的记录，但它没有明确指出哪个是哪个（我猜 `+` 意味着它在附加部分？） ，但它似乎没有显示“权威”部分的记录。 + +``` +$ dog @h.root-servers.net. jvns.ca + NS ca. 2d0h00m00s A "c.ca-servers.ca." + NS ca. 2d0h00m00s A "j.ca-servers.ca." + NS ca. 2d0h00m00s A "x.ca-servers.ca." + NS ca. 2d0h00m00s A "any.ca-servers.ca." + A c.ca-servers.ca. 2d0h00m00s + 185.159.196.2 + A j.ca-servers.ca. 2d0h00m00s + 198.182.167.1 + A x.ca-servers.ca. 2d0h00m00s + 199.253.250.68 + A any.ca-servers.ca. 2d0h00m00s + 199.4.144.2 +AAAA c.ca-servers.ca. 2d0h00m00s + 2620:10a:8053::2 +AAAA j.ca-servers.ca. 2d0h00m00s + 2001:500:83::1 +AAAA x.ca-servers.ca. 2d0h00m00s + 2620:10a:80ba::68 +AAAA any.ca-servers.ca. 2d0h00m00s + 2001:500:a7::2 +``` + +而 `host` 似乎只显示“答案”部分的记录（在这种情况下没有得到记录）： + +``` +$ host jvns.ca h.root-servers.net +Using domain server: +Name: h.root-servers.net +Address: 198.97.190.53#53 +Aliases: +``` + +总之，我认为这些更简单的 DNS 工具很好（我甚至自己做了一个 [简单的网络 DNS 工具][2]），如果你觉得它们更容易，你绝对应该使用它们，但这就是为什么我坚持使用 `dig` 的原因。`drill’ 的输出格式似乎与 `dig` 的非常相似，也许 `drill` 更好！但我还没有真正试过它。 + +### 就这些了 + +我最近才知道 `.digrc`，我非常喜欢使用它，所以我希望它能帮助你们中的一些人花更少的时间来整理 `dig` 的输出！ + +有人在 Twitter 上指出，如果有办法让 `dig` 显示响应的简短版本，其中也包括响应的状态（如 `NOERROR`、`NXDOMAIN`、`SERVFAIL` 等），那就更好了！我同意这个观点！不过我在手册中没有找到这样的选项。 + +-------------------------------------------------------------------------------- + +via: https://jvns.ca/blog/2021/12/04/how-to-use-dig/ + +作者：[Julia Evans][a] +选题：[lujun9972][b] +译者：[wxy](https://github.com/wxy) +校对：[wxy](https://github.com/wxy) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://jvns.ca/ +[b]: https://github.com/lujun9972 +[1]: https://wizardzines.com/comics/dig/ +[2]: https://dns-lookup.jvns.ca/