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Do DNS messages pad names to an even number of bytes?

Preliminary note Yes, I am aware of the existence of DNS libraries and easy-to-use DNS servers. I am doing this purely for academic purposes, and to get a grasp of how DNS queries work. The question I was looking at RFC 1035 to get an idea of how DNS messages work. I think I more or less understood everything in that memo. There is one thing that I can't interpret autonomously, however. If you look at Section 4.1.3, here is how the resource record format is described: 1 1 1 1 1 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ | | / / / NAME / | | +--+--+--+--

2022-05-01 07:14:08    分类:问答    dns   rfc   rfc1035

What does "clock sequence" mean?

问题 RFC 4122(通用唯一标识符 (UUID) URN 命名空间)使用术语“时钟序列”: 4.1.5。 时钟序列 对于 UUID 版本 1,时钟序列用于帮助避免在时钟向后设置或节点 ID 更改时可能出现的重复。 如果时钟向后设置,或者可能已经向后设置(例如,系统关闭时),并且 UUID 生成器无法确定没有生成时间戳大于时钟设置值的 UUID,然后必须更改时钟序列。 如果时钟序列的前一个值是已知的,就可以递增; 否则应设置为随机或高质量的伪随机值。 类似地,如果节点 ID 发生变化(例如,因为在机器之间移动了网卡),将时钟序列设置为随机数可以最大限度地减少由于机器时钟设置的细微差异而导致重复的概率。 如果与更改的节点 ID 相关联的时钟序列的值已知,则时钟序列可以只增加,但这不太可能。 时钟序列必须最初(即,在系统的生命周期中)初始化为一个随机数,以最小化跨系统的相关性。 这为节点标识符提供了最大程度的保护,这些节点标识符可能会在系统之间快速移动或切换。 初始值不得与节点标识符相关。 对于 UUID 版本 3 或 5,时钟序列是一个 14 位值,由 4.3 节中描述的名称构成。 对于 UUID 版本 4,时钟序列是随机或伪随机生成的 14 位值,如第 4.4 节所述。 这个词是什么意思? 回答1 “时钟序列”似乎是一个真正具有误导性的名称。 根据其定义,更好的名称可能是

2022-04-29 10:37:03    分类:技术分享    uuid   guid   rfc   dce

multipart/form-data, what is the default charset for fields?

问题 如果没有给出字符集,应该使用什么默认编码来解码多部分/表单数据? RFC2388 指出: 4.5 表单数据中的文本字符集 multipart/form-data 的每个部分都应该有一个内容类型。 在字段元素是文本的情况下,文本的 charset 参数指示使用的字符编码。 例如,一个带有文本字段的表单,其中用户键入了“Joe owes <eu>100”,其中 <eu> 是欧元符号,表单数据可能返回为: --AaB03x content-disposition: form-data; name="field1" content-type: text/plain;charset=windows-1250 content-transfer-encoding: quoted-printable>> Joe owes =80100. --AaB03x 就我而言,未设置字符集,我不知道如何解码该文本/纯文本部分中的数据。 因为我不想强制执行一些不是标准行为的东西,所以我在问这种情况下的预期行为是什么。 RFC 似乎没有解释这一点,所以我有点迷路了。 谢谢! 回答1 这显然在 HTML5 中发生了变化(参见 http://dev.w3.org/html5/spec-preview/constraints.html#multipart-form-data)。 生成的 multipart

2022-04-28 17:21:16    分类:技术分享    http   standards-compliance   multipartform-data   rfc

When I add "METHOD: REQUEST" to iCalendar, Gmail stops recognizing as event

I'm using iCalendar to schedule events for Gmail users. However, I want to be able to send updates, if/when the event changes. I read that I must use METHOD:REQUEST in order to allow updates. However, when I add the METHOD:REQUEST to my ics file, Gmail stops recognizing it as a calendar invite. Here is the working example WITHOUT "METHOD:REQUEST" BEGIN:VCALENDAR VERSION:2.0 PRODID:-//Cratic//Cratic Huddle//EN NAME:Cratic Huddle X-WR-CALNAME:Cratic Huddle TIMEZONE-ID:Europe/Berlin X-WR-TIMEZONE:Europe/Berlin BEGIN:VEVENT UID:60212c8395841f2cd057864f@cratic.ai SEQUENCE:0 DTSTAMP:20210208T130601Z

2022-04-26 18:22:09    分类:问答    javascript   outlook   gmail   icalendar   rfc

What does "clock sequence" mean?

RFC 4122 (A Universally Unique IDentifier (UUID) URN Namespace) uses the term "clock sequence": 4.1.5. Clock Sequence For UUID version 1, the clock sequence is used to help avoid duplicates that could arise when the clock is set backwards in time or if the node ID changes. If the clock is set backwards, or might have been set backwards (e.g., while the system was powered off), and the UUID generator can not be sure that no UUIDs were generated with timestamps larger than the value to which the clock was set, then the clock sequence has to be changed. If the previous value of the clock sequence

2022-04-05 09:51:04    分类:问答    uuid   guid   rfc   dce

What is the max rtsp(over tcp) packet size?

I didn't see about it anything in Real Time Streaming Protocol (RTSP) , but when I sniffing , I saw the max rtsp packet size is 1440. And like you can see here RTSP - RTP over TCP RTP Data After the setup, RTP data will be sent through the TCP socket that is used for RTSP commands. The RTP data will be encapsulate in the following format | magic number | channel number | embedded data length | data | magic number - 1 byte value of hex 0x24 channel number - 1 byte value to denote the channel embedded data length - 2 bytes to denote the embedded data length data - data packet, ie RTP packet

2022-03-24 05:08:47    分类:问答    protocols   rtsp   rtp   rfc

Netconf Notifications

RFC 5277 defines notification replay support. Just wondering what customer problems this notification replay can solve? What could be the need to scan through list of past notifications? At any point of time, controllers can always fire "get" RPC and determine current state. Any inputs on this are appreciated.

2022-03-22 15:54:51    分类:问答    rfc   ietf-netmod-yang   ietf-netconf

Looking to build some regex to validate domain names (RFC 952/ RFC 1123)

One of our clients validates email addresses in their own software prior to firing it via an API call to our system. The issue is however that their validation rules do not match those our system, therefore they are parsing and accepting addresses which break our rules. This is causing lots of failed calls. They are parsing stuff like "dave@-whatever.com", this goes against RFC 952/RFC 1123 rules as it begins with a hyphen. They have asked that we provide them with our regex list so they can update validation on their platform to match ours. So, I need to find/build an RFC 952/RFC 1123

2022-03-22 03:33:42    分类:问答    regex   api   rfc   rfc1123