https://www.domaindiscount24.com/faq/en/txt-record
Please note It needs time for changes in the DNS to take effect. In case a single TXT record is longer than 255 characters you have to split it into two parts (like "1stpart" "2ndpart") to add it into a single line. This is because Strings in DNS records have a maximum of 255 characters according to RFC. By splitting the record with double quotes this limitation can be avoided.
^
获取时间戳
[root@s6 ~]# date +%s%N 1634089185225960225 [root@s6 ~]#
获取系统的唯一性ID
[root@s6 ~]# cat /etc/machine-id 52e2104a451e6cc4c0cd3f75608ba59f [root@s6 ~]#
通过hostnamectl查看
[root@s6 ~]# hostnamectl
Static hostname: s6.linuxcache.com
Icon name: computer-vm
Chassis: vm
Machine ID: 52e2104a451e6cc4c0cd3f75608ba59f
Boot ID: 7b76dcb309d94c908ec297b10998cd38
Virtualization: kvm
Operating System: Fedora 34 (Server Edition)
CPE OS Name: cpe:/o:fedoraproject:fedora:34
Kernel: Linux 5.11.12-300.fc34.x86_64
Architecture: x86-64
Hardware Vendor: Vultr
Hardware Model: HFC
[root@s6 ~]#
拼接timestamp和machine-id并使用sha1算法计算校验值
printf <timestamp><machine-id> | sha1sum printf 163408918522596022552e2104a451e6cc4c0cd3f75608ba59f | sha1sum
计算校验值
[root@s6 ~]# printf 163408918522596022552e2104a451e6cc4c0cd3f75608ba59f | sha1sum e4819b79f35d65e8231cb7e23bf61fc76aab5571 - [root@s6 ~]#
截取后5位16进制值
printf e4819b79f35d65e8231cb7e23bf61fc76aab5571 | cut -c 31-
截取成功
[root@s6 ~]# printf e4819b79f35d65e8231cb7e23bf61fc76aab5571 | cut -c 31- c76aab5571 [root@s6 ~]#
拼接前缀
fd c7 6a ab 55 71 fdc7:6aab:5571::/64
使用ipcalc命令计算子网信息 [root@s6 ~]# ipcalc -6 fdc7:6aab:5571::/64 Full Network: fdc7:6aab:5571:0000:0000:0000:0000:0000/64 Network: fdc7:6aab:5571::/64 Netmask: ffff:ffff:ffff:ffff:: = 64 Address space: Unique Local Unicast HostMin: fdc7:6aab:5571:: HostMax: fdc7:6aab:5571:0:ffff:ffff:ffff:ffff Hosts/Net: 2^(64) = 18446744073709551616 [root@s6 ~]#
原文
3.2.2. Sample Code for Pseudo-Random Global ID Algorithm The algorithm described below is intended to be used for locally assigned Global IDs. In each case the resulting global ID will be used in the appropriate prefix as defined in Section 3.2. 1) Obtain the current time of day in 64-bit NTP format [NTP]. 2) Obtain an EUI-64 identifier from the system running this algorithm. If an EUI-64 does not exist, one can be created from a 48-bit MAC address as specified in [ADDARCH]. If an EUI-64 cannot be obtained or created, a suitably unique identifier, local to the node, should be used (e.g., system serial number). 3) Concatenate the time of day with the system-specific identifier in order to create a key. 4) Compute an SHA-1 digest on the key as specified in [FIPS, SHA1]; the resulting value is 160 bits. 5) Use the least significant 40 bits as the Global ID. 6) Concatenate FC00::/7, the L bit set to 1, and the 40-bit Global ID to create a Local IPv6 address prefix. This algorithm will result in a Global ID that is reasonably unique and can be used to create a locally assigned Local IPv6 address prefix.
内容引用：
生成私钥
$ umask 077 $ wg genkey > privatekey
由私钥生成公钥
$ wg pubkey < privatekey > publickey
一次性生成私钥和公钥
$ wg genkey | tee privatekey | wg pubkey > publickey
客户端标准配置文件
[Interface]
PrivateKey =
Address = 172.16.0.1/24
DNS = 8.8.8.8, 8.8.4.4
[Peer]
PublicKey =
AllowedIPs = 0.0.0.0/0, ::/0
Endpoint = hostname.com:51820
PersistentKeepalive = 25
生成二维码
方式1
$ qrencode -t ansiutf8 -r client.conf
方式2
$ qrencode -t ansiutf8 < client.conf
方式3
$ qrencode -t png -o client.png -r client.conf
AnyConnect Deployment Overview
Deploying AnyConnect refers to installing, configuring, and upgrading the AnyConnect client and its related files.
The Cisco AnyConnect Secure Mobility Client can be deployed to remote users by the following methods:
Predeploy—New installations and upgrades are done either by the end user, or by using an enterprise software management system (SMS).
Web Deploy—The AnyConnect package is loaded on the headend, which is either an ASA or FTD firewall, or an ISE server. When the user connects to a firewall or to ISE, AnyConnect is deployed to the client.
For new installations, the user connects to a headend to download the AnyConnect client. The client is either installed manually or automatically (web-launch).
Updates are done by AnyConnect running on a system where AnyConnect is already installed, or by directing the user to the ASA clientless portal.
When you deploy AnyConnect, you can include optional modules that enable extra features, and client profiles that configure the VPN and optional features.
Refer to the AnyConnect release notes for system, management, and endpoint requirements for ASA, IOS, Microsoft Windows, Linux, and macOS.
内容引用：
通过查看dmesg信息获取当前文本终端的默认显示分辨率
[ 4.426948] [drm] DMA map mode: Caching DMA mappings. [ 4.427281] [drm] Capabilities: [ 4.427282] [drm] Rect copy. [ 4.427282] [drm] Cursor. [ 4.427283] [drm] Cursor bypass. [ 4.427283] [drm] Cursor bypass 2. [ 4.427283] [drm] 8bit emulation. [ 4.427284] [drm] Alpha cursor. [ 4.427284] [drm] 3D. [ 4.427284] [drm] Extended Fifo. [ 4.427284] [drm] Multimon. [ 4.427285] [drm] Pitchlock. [ 4.427285] [drm] Irq mask. [ 4.427285] [drm] Display Topology. [ 4.427286] [drm] GMR. [ 4.427286] [drm] Traces. [ 4.427286] [drm] GMR2. [ 4.427286] [drm] Screen Object 2. [ 4.427287] [drm] Command Buffers. [ 4.427287] [drm] Command Buffers 2. [ 4.427287] [drm] Guest Backed Resources. [ 4.427288] [drm] DX Features. [ 4.427288] [drm] HP Command Queue. [ 4.427288] [drm] Capabilities2: [ 4.427289] [drm] Grow oTable. [ 4.427289] [drm] IntraSurface copy. [ 4.427289] [drm] DX3. [ 4.427290] [drm] Max GMR ids is 64 [ 4.427291] [drm] Max number of GMR pages is 65536 [ 4.427292] [drm] Max dedicated hypervisor surface memory is 0 kiB [ 4.427292] [drm] Maximum display memory size is 262144 kiB [ 4.427293] [drm] VRAM at 0xe8000000 size is 131072 kiB [ 4.427294] [drm] MMIO at 0xfe000000 size is 256 kiB [ 4.437927] [TTM] Zone kernel: Available graphics memory: 996108 KiB [ 4.464121] [drm] Screen Target Display device initialized [ 4.464193] [drm] width 1280 [ 4.464211] [drm] height 768 [ 4.464229] [drm] bpp 32 [ 4.493584] [drm] Fifo max 0x00040000 min 0x00001000 cap 0x0000077f [ 4.591064] [drm] Using command buffers with DMA pool. [ 4.594738] [drm] Atomic: yes. [ 4.594741] [drm] SM5 support available.
通过hwinfo命令查看当前可用的分辨率模式
[root@fedora ~]# hwinfo --framebuffer 02: None 00.0: 11001 VESA Framebuffer [Created at bios.459] Unique ID: rdCR.O3PgoQaqFo1 Hardware Class: framebuffer Model: "VMware virtual machine" Vendor: "VMware, Inc" Device: "VMware virtual machine" SubVendor: "V M ware, Inc. VBE support 2.0" SubDevice: Revision: "2.0" Memory Size: 0 MB Memory Range: 0xe8000000-??? (rw) Mode 0x0300: 640x400 (+640), 8 bits Mode 0x0301: 640x480 (+640), 8 bits Mode 0x0303: 800x600 (+800), 8 bits Mode 0x0305: 1024x768 (+1024), 8 bits Mode 0x0307: 1280x1024 (+1280), 8 bits Mode 0x030e: 320x200 (+640), 16 bits Mode 0x0311: 640x480 (+1280), 16 bits Mode 0x0314: 800x600 (+1600), 16 bits Mode 0x0317: 1024x768 (+2048), 16 bits Mode 0x031a: 1280x1024 (+2560), 16 bits Mode 0x0320: 320x200 (+320), 8 bits Mode 0x0321: 320x400 (+320), 8 bits Mode 0x0322: 640x400 (+640), 8 bits Mode 0x0323: 640x480 (+640), 8 bits Mode 0x0324: 800x600 (+800), 8 bits Mode 0x0325: 1024x768 (+1024), 8 bits Mode 0x0326: 1152x864 (+1152), 8 bits Mode 0x0327: 1280x960 (+1280), 8 bits Mode 0x0328: 1280x1024 (+1280), 8 bits Mode 0x0329: 1400x1050 (+1408), 8 bits Mode 0x032a: 1600x1200 (+1600), 8 bits Mode 0x032b: 1792x1344 (+1792), 8 bits Mode 0x032c: 1856x1392 (+1856), 8 bits Mode 0x032d: 1920x1440 (+1920), 8 bits Mode 0x032e: 320x200 (+640), 16 bits Mode 0x032f: 320x400 (+640), 16 bits Mode 0x0330: 640x400 (+1280), 16 bits Mode 0x0331: 640x480 (+1280), 16 bits Mode 0x0332: 800x600 (+1600), 16 bits Mode 0x0333: 1024x768 (+2048), 16 bits Mode 0x0334: 1152x864 (+2304), 16 bits Mode 0x0335: 1280x960 (+2560), 16 bits Mode 0x0336: 1280x1024 (+2560), 16 bits Mode 0x0337: 1400x1050 (+2816), 16 bits Mode 0x0338: 1600x1200 (+3200), 16 bits Mode 0x0339: 1792x1344 (+3584), 16 bits Mode 0x033a: 1856x1392 (+3712), 16 bits Mode 0x033b: 1920x1440 (+3840), 16 bits Mode 0x033c: 320x200 (+1280), 24 bits Mode 0x033d: 320x400 (+1280), 24 bits Mode 0x033e: 640x400 (+2560), 24 bits Mode 0x033f: 640x480 (+2560), 24 bits Mode 0x0340: 800x600 (+3200), 24 bits Mode 0x0341: 1024x768 (+4096), 24 bits Mode 0x0342: 1152x864 (+4608), 24 bits Mode 0x0343: 1280x960 (+5120), 24 bits Mode 0x0344: 1280x1024 (+5120), 24 bits Mode 0x0345: 1400x1050 (+5600), 24 bits Mode 0x0346: 1600x1200 (+6400), 24 bits Mode 0x0347: 1792x1344 (+7168), 24 bits Mode 0x0348: 1856x1392 (+7424), 24 bits Mode 0x0349: 1920x1440 (+7680), 24 bits Mode 0x034a: 1366x768 (+1376), 8 bits Mode 0x034b: 1366x768 (+2752), 16 bits Mode 0x034c: 1366x768 (+5472), 24 bits Mode 0x034d: 1680x1050 (+1696), 8 bits Mode 0x034e: 1680x1050 (+3360), 16 bits Mode 0x034f: 1680x1050 (+6720), 24 bits Mode 0x0350: 1920x1200 (+1920), 8 bits Mode 0x0351: 1920x1200 (+3840), 16 bits Mode 0x0352: 1920x1200 (+7680), 24 bits Mode 0x0353: 2048x1536 (+2048), 8 bits Mode 0x0354: 2048x1536 (+4096), 16 bits Mode 0x0355: 2048x1536 (+8192), 24 bits Mode 0x0356: 320x240 (+320), 8 bits Mode 0x0357: 320x240 (+640), 16 bits Mode 0x0358: 320x240 (+1280), 24 bits Mode 0x0359: 400x300 (+416), 8 bits Mode 0x035a: 400x300 (+800), 16 bits Mode 0x035b: 400x300 (+1600), 24 bits Mode 0x035c: 512x384 (+512), 8 bits Mode 0x035d: 512x384 (+1024), 16 bits Mode 0x035e: 512x384 (+2048), 24 bits Mode 0x035f: 854x480 (+864), 8 bits Mode 0x0360: 854x480 (+1728), 16 bits Mode 0x0361: 854x480 (+3424), 24 bits Mode 0x0362: 1280x720 (+1280), 8 bits Mode 0x0363: 1280x720 (+2560), 16 bits Mode 0x0364: 1280x720 (+5120), 24 bits Mode 0x0365: 1920x1080 (+1920), 8 bits Mode 0x0366: 1920x1080 (+3840), 16 bits Mode 0x0367: 1920x1080 (+7680), 24 bits Mode 0x0368: 1280x800 (+1280), 8 bits Mode 0x0369: 1280x800 (+2560), 16 bits Mode 0x036a: 1280x800 (+5120), 24 bits Mode 0x036b: 1440x900 (+1440), 8 bits Mode 0x036c: 1440x900 (+2880), 16 bits Mode 0x036d: 1440x900 (+5760), 24 bits Mode 0x036e: 720x480 (+736), 8 bits Mode 0x036f: 720x480 (+1440), 16 bits Mode 0x0370: 720x480 (+2880), 24 bits Mode 0x0371: 720x576 (+736), 8 bits Mode 0x0372: 720x576 (+1440), 16 bits Mode 0x0373: 720x576 (+2880), 24 bits Mode 0x0374: 800x480 (+800), 8 bits Mode 0x0375: 800x480 (+1600), 16 bits Mode 0x0376: 800x480 (+3200), 24 bits Mode 0x0377: 1280x768 (+1280), 8 bits Mode 0x0378: 1280x768 (+2560), 16 bits Mode 0x0379: 1280x768 (+5120), 24 bits Config Status: cfg=new, avail=yes, need=no, active=unknown [root@fedora ~]#
修改文本终端分辨率模式的三种方法
1）在Linux启动阶段输出可用分辨率模式并由用户选择
vga=ask
2）在Linux启动阶段手动添加分辨率模式参数
vga=0x0364
3）修改GRUB2引导菜单配置，永久新增分辨率模式参数
[root@fedora ~]# grubby --default-kernel /boot/vmlinuz-5.11.12-300.fc34.x86_64 [root@fedora ~]# grubby --args="vga=0x0364" --update-kernel /boot/vmlinuz-5.11.12-300.fc34.x86_64 [root@fedora ~]#
修改GRUB2引导菜单配置并重启后查看GRUB2引导菜单的变化
查看分辨率为1280*720的虚拟机文本终端窗口
https://docs.fedoraproject.org/en-US/fedora/rawhide/system-administrators-guide/kernel-module-driver-configuration/Working_with_the_GRUB_2_Boot_Loader/#sec-Making_Persistent_Changes_to_a_GRUB_2_Menu_Using_the_grubby_Tool
视频分辨率和宽高比
YouTube 会根据所用的平台和视频格式，以不同的宽高比播放视频。YouTube 视频播放器会自动根据每个视频的尺寸调整大小。 视频显示方式 YouTube 在计算机上的标准宽高比为 16:9。如果您的视频具有不同的宽高比，则播放器将自动变为理想尺寸以匹配您的视频和观看者的设备。 对于某些视频和设备宽高比（例如计算机浏览器中显示的 9:16 竖版视频），YouTube 可能会添加额外的内边框以实现理想的观看效果。内边框默认为白色，但在启用“深色主题背景”的情况下为深灰色。 为了实现理想效果，请避免直接在视频中添加内边框或黑边。视频自带的内边框会干扰 YouTube 根据您的视频尺寸和观看者的设备动态调整播放器的能力。
推荐的分辨率和宽高比
对于默认的 16:9 宽高比，请按以下分辨率进行编码： 2160p：3840x2160 1440p：2560x1440 1080p：1920x1080 720p：1280x720 480p：854x480 360p：640x360 240p：426x240
https://support.google.com/youtube/answer/6375112?hl=zh-Hans
