timedatectl status Local time: Sat 2024-09-14 21:56:01 CST Universal time: Sat 2024-09-14 13:56:01 UTC RTC time: Sat 2024-09-14 13:55:53 Time zone: Asia/Shanghai (CST, +0800) System clock synchronized: no NTP service: n/a RTC in local TZ: no
timedatectl status Local time: Sat 2024-09-14 21:56:07 CST Universal time: Sat 2024-09-14 13:56:07 UTC RTC time: n/a Time zone: Asia/Shanghai (CST, +0800) System clock synchronized: no NTP service: n/a RTC in local TZ: no
% Appropriate date and time representation for date(1). This is % different from d_t_fmt for historical reasons and has been different % since 2000 when date_fmt was added as a GNU extension. At the end % of 2018 it was adjusted to use 12H time (bug 24046) instead of 24H.
$ traceroute6 www.amazon.com
traceroute6: `www-amazon-com.customer.fastly.net' has multiple addresses; using `2606:2cc0::374'
traceroute6 to www-amazon-com.customer.fastly.net (2606:2cc0::374) from 2600:1f18:400c:b800:bdf1:6584:1971:4efe, 64 hops max, 12 byte packets
1 2620:107:4000:2210:8000:0:f405:667 58.911 ms # 244.5.102.7
2620:107:4000:2210:8000:0:3ec:3e71 0.831 ms
2620:107:4000:2210:8000:0:3ec:3e73 0.808 ms
2 2620:107:4000:a792::f000:3841 0.419 ms # 240.0.56.65
2620:107:4000:a792::f000:3843 0.473 ms
2620:107:4000:a792::f000:3842 0.4 ms
3 2620:107:4000:cfff::f20c:2b01 17.258 ms # 242.12.43.1
2620:107:4000:cfff::f20c:2b81 12.562 ms
2620:107:4000:cfff::f200:e353 2.026 ms
4 2620:107:4000:c5c0::f3fd:1 1429.46 ms 1299.83 ms
2620:107:4000:c5c0::f3fd:3 1368.37 ms
5 2620:107:4000:cfff::f202:d4c3 2.15 ms
2620:107:4000:cfff::f202:d545 1.931 ms
2620:107:4000:cfff::f202:d445 1.358 ms
6 2620:107:4000:8001::24 2.469 ms
2620:107:4000:8001::44 10.271 ms
2620:107:4000:8001::24 1.16 ms
[...]
$
总之,我想你明白我要说的是什么了:我们被告知,IANA 将 IP 空间分配给地区注册管理机构,他们进一步管理分配的网络块。一些早期采用者从 Jon Postel(最初的 IANA)那里得到了一份特别的礼物:他们自己的 /8。
在区域注册表级别,可用的 IP 空间没有均匀分配。如果我们去掉保留的 IP 空间(总共 35 /8,包括 E 类、组播和选定的其他网络块),只查看分配给不同区域互联网注册机构 (RIR) 的实际可用 IP 地址,那么我们会发现 ARIN 管理着超过 50% 的 IPv4 IP 空间,而 AFRINIC 只管理着 2.7%。相比之下,IPv6 地址空间的分配要均匀得多:
当然,当我们用完 IP 地址时,网络块被重新分配和重新分配,在区域注册表之间转移,公司开始交易网络块,如果你有一个备用的 /9 左右,这被证明是一个非常好的快速赚钱方式。
但观察到的 AS 频率是一个因素。如果我们统计给定 CIDR 的 IP 地址并按 AS 映射这些地址,则会出现不同的视图:
换句话说,我们发现自己是触摸大象的盲人之一——我们从不同的侧面得到不同的观点,却没有真正得到完整的视角。尝试将 AS 编号和网络名称组合在一起并手动将它们与实体相关联,我得出了拥有最多 IP 地址的顶级组织的粗略分布,这些地址占所有 IP 空间的很大一部分,并且至少在一定程度上回答了我们最初的问题。前十名(无论如何,按这个计数计算)是:
美国国防部(352M 个 IP 地址,占所有 IPv4 地址的 8.19%)
亚马逊(181M,4.21%)
中国电信 (112M, 2.61%)
AT&T (111M, 2.59%)
Verizon (101M,2.35%)
康卡斯特 (71M, 1.64%)
Lumen Technologies (65M, 1.52%)
Microsoft(59M,1.37%)
软银 (48M, 1.1%)
韩国电信 (46M, 1.08%)
这里需要指出的一点(除了 DoD 是一个明显的异类)是只有两家公司不是电信提供商:Amazon 和 Microsoft。所有其他公司实际上是 ISP 和 Telco。
failed to fetch https://nginx.org/packages/mainline/debian/dists/bookworm/inrelease the following signatures were invalid: expkeysig abf5bd827bd9bf62 nginx signing key <signing-key@nginx.com>
# 显示PHP程序的可替换信息
update-alternatives --display php
php - manual mode
link best version is /usr/bin/php8.3
link currently points to /usr/bin/php8.2
link php is /usr/bin/php
slave php.1.gz is /usr/share/man/man1/php.1.gz
/usr/bin/php8.2 - priority 82
slave php.1.gz: /usr/share/man/man1/php8.2.1.gz
/usr/bin/php8.3 - priority 83
slave php.1.gz: /usr/share/man/man1/php8.3.1.gz
#设置默认浏览器
update-alternatives --config www-browser
There is 1 choice for the alternative www-browser (providing /usr/bin/www-browser).
Selection Path Priority Status
------------------------------------------------------------
* 0 /usr/bin/w3m 25 auto mode
1 /usr/bin/w3m 25 manual mode
Press <enter> to keep the current choice[*], or type selection number:
#设置默认使用的php版本
update-alternatives --config php
There are 2 choices for the alternative php (providing /usr/bin/php).
Selection Path Priority Status
------------------------------------------------------------
0 /usr/bin/php8.3 83 auto mode
* 1 /usr/bin/php8.2 82 manual mode
2 /usr/bin/php8.3 83 manual mode
Press <enter> to keep the current choice[*], or type selection number: 1
Err:5 https://packages.microsoft.com/debian/12/prod bookworm InRelease The following signatures couldn’t be verified because the public key is not available: NO_PUBKEY EB3E94ADBE1229CF
W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: https://packages.microsoft.com/debian/12/prod bookworm InRelease: The following signatures couldn’t be verified because the public key is not available: NO_PUBKEY EB3E94ADBE1229CF
deb [arch=amd64,arm64,armhf signed-by=/usr/share/keyrings/microsoft-prod.gpg] https://packages.microsoft.com/debian/12/prod bookworm main
② Hit:6 https://packages.sury.org/php bookworm InRelease
W: https://packages.sury.org/php/dists/bookworm/InRelease: Key is stored in legacy trusted.gpg keyring (/etc/apt/trusted.gpg), see the DEPRECATION section in apt-key(8) for details. W: Failed to fetch https://packages.microsoft.com/debian/12/prod/dists/bookworm/InRelease The following signatures couldn’t be verified because the public key is not available: NO_PUBKEY EB3E94ADBE1229CF W: Some index files failed to download. They have been ignored, or old ones used instead.