内容一:lldpad 命令的安装
如果是 Rocky Linux & RHEL
# yum install lldpad
如果是 openSUSE & SLES
# zypper in lldpad
内容二:查看网卡接入交换机的接口信息
# lldptool -t -n -i eth0
(补充:这里以查看本地网卡 eth0 接入的交换机的接口信息为例)
如果是 Rocky Linux & RHEL
# yum install lldpad
如果是 openSUSE & SLES
# zypper in lldpad
# lldptool -t -n -i eth0
(补充:这里以查看本地网卡 eth0 接入的交换机的接口信息为例)
$ who -b
system boot 2024-09-16 17:52
$ last | grep "reboot" | head -1
reboot system boot 6.8.0-44-generic Mon Sep 16 17:52 still running
或者:
$ last reboot | head -1
reboot system boot 6.8.0-44-generic Mon Sep 16 17:52 still running
或者:
$ last reboot -n 1
reboot system boot 6.8.0-44-generic Mon Sep 16 17:52 still running
wtmp begins Wed Aug 14 10:01:22 2024
$ last reboot -F
reboot system boot 6.8.0-44-generic Mon Sep 16 17:52:25 2024 still running
reboot system boot 6.8.0-41-generic Fri Sep 6 21:53:12 2024 - Mon Sep 16 17:52:18 2024 (9+19:59)
wtmp begins Wed Aug 14 10:01:22 2024
$ uptime -s
2024-09-16 17:52:23
$ uptime
15:16:17 up 14 days, 21:23, 3 users, load average: 0.15, 0.13, 0.06
$ uptime -p
up 2 weeks, 21 hours, 24 minutes
$ top -bn 1 | head -1
top - 15:40:47 up 14 days, 21:48, 3 users, load average: 0.02, 0.03, 0.01
$ top
top - 15:42:19 up 14 days, 21:49, 3 users, load average: 0.00, 0.02, 0.00
Tasks: 289 total, 1 running, 287 sleeping, 0 stopped, 1 zombie
%Cpu(s): 2.2 us, 2.2 sy, 0.0 ni, 93.3 id, 0.0 wa, 0.0 hi, 2.2 si, 0.0 st
MiB Mem : 3915.3 total, 247.9 free, 2984.8 used, 985.0 buff/cache
MiB Swap: 256.0 total, 0.0 free, 256.0 used. 930.5 avail Mem
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
1056592 mingyuz+ 0 -20 133764 38484 25292 S 18.2 1.0 0:35.55 nxcodec.bin
1 root 20 0 23132 12112 7376 S 0.0 0.3 1:39.97 systemd
2 root 20 0 0 0 0 S 0.0 0.0 0:00.27 kthreadd
3 root 20 0 0 0 0 S 0.0 0.0 0:00.00 pool_workque+
4 root 0 -20 0 0 0 I 0.0 0.0 0:00.00 kworker/R-rc+
5 root 0 -20 0 0 0 I 0.0 0.0 0:00.00 kworker/R-rc+
6 root 0 -20 0 0 0 I 0.0 0.0 0:00.00 kworker/R-sl+
7 root 0 -20 0 0 0 I 0.0 0.0 0:00.00 kworker/R-ne+
9 root 0 -20 0 0 0 I 0.0 0.0 0:00.00 kworker/0:0H+
12 root 0 -20 0 0 0 I 0.0 0.0 0:00.00 kworker/R-mm+
13 root 20 0 0 0 0 I 0.0 0.0 0:00.00 rcu_tasks_kt+
14 root 20 0 0 0 0 I 0.0 0.0 0:00.00 rcu_tasks_ru+
15 root 20 0 0 0 0 I 0.0 0.0 0:00.00 rcu_tasks_tr+
16 root 20 0 0 0 0 S 0.0 0.0 0:08.00 ksoftirqd/0
17 root 20 0 0 0 0 I 0.0 0.0 30:45.37 rcu_preempt
18 root rt 0 0 0 0 S 0.0 0.0 0:04.93 migration/0
......
$ journalctl --list-boot
IDX BOOT ID FIRST ENTRY LAST ENTRY >
-17 d842be174b26429c84b6c21d8c457ca0 Wed 2024-08-14 10:01:22 CST Wed 2024-08-14>
-16 76b3d204a98d4004809d34add8838c3f Wed 2024-08-14 10:02:14 CST Wed 2024-08-14>
-15 50f754cd41af43119d88d9ca13306d09 Wed 2024-08-14 11:11:42 CST Wed 2024-08-14>
lines 1-19/19 (END)
......
(补充:从这里可以看出最后一次系统重启的 BOOT ID 是 d842be174b26429c84b6c21d8c457ca0)
$ journalctl -b d842be174b26429c84b6c21d8c457ca0
Aug 14 10:01:22 linux-template kernel: Linux version 6.8.0-35-generic (buildd@lcy02->
Aug 14 10:01:22 linux-template kernel: Command line: BOOT_IMAGE=/boot/vmlinuz-6.8.0->
Aug 14 10:01:22 linux-template kernel: KERNEL supported cpus:
Aug 14 10:01:22 linux-template kernel: Intel GenuineIntel
Aug 14 10:01:22 linux-template kernel: AMD AuthenticAMD
Aug 14 10:01:22 linux-template kernel: Hygon HygonGenuine
Aug 14 10:01:22 linux-template kernel: Centaur CentaurHauls
Aug 14 10:01:22 linux-template kernel: zhaoxin Shanghai
Aug 14 10:01:22 linux-template kernel: BIOS-provided physical RAM map:
Aug 14 10:01:22 linux-template kernel: BIOS-e820: [mem 0x0000000000000000-0x00000000>
Aug 14 10:01:22 linux-template kernel: BIOS-e820: [mem 0x000000000009fc00-0x00000000>
Aug 14 10:01:22 linux-template kernel: BIOS-e820: [mem 0x00000000000f0000-0x00000000>
Aug 14 10:01:22 linux-template kernel: BIOS-e820: [mem 0x0000000000100000-0x00000000>
Aug 14 10:01:22 linux-template kernel: BIOS-e820: [mem 0x000000007ffd4000-0x00000000>
Aug 14 10:01:22 linux-template kernel: BIOS-e820: [mem 0x00000000b0000000-0x00000000>
Aug 14 10:01:22 linux-template kernel: BIOS-e820: [mem 0x00000000fed1c000-0x00000000>
Aug 14 10:01:22 linux-template kernel: BIOS-e820: [mem 0x00000000feffc000-0x00000000>
Aug 14 10:01:22 linux-template kernel: BIOS-e820: [mem 0x00000000fffc0000-0x00000000>
Aug 14 10:01:22 linux-template kernel: BIOS-e820: [mem 0x0000000100000000-0x00000001>
Aug 14 10:01:22 linux-template kernel: NX (Execute Disable) protection: active
Aug 14 10:01:22 linux-template kernel: APIC: Static calls initialized
Aug 14 10:01:22 linux-template kernel: SMBIOS 2.8 present.
......
(补充:这里查看的 BOOT ID 是 d842be174b26429c84b6c21d8c457ca0)
https://www.sysgeek.cn/linux-reboot-history
/dev/vg/lv_var /var xfs nodev,nosuid,noexec 0 0
/dev/vg/lv_var_log /var/log xfs nodev,nosuid,noexec,x-systemd.requires-mounts-for=/var 0 0
(
Add:
1) nodev parameter here means this directory can not be interpreted by devices or blocks
2) nosuid parameter here means no setuid files can be created in this directory
3) noexec parameter here means no files can be executed in this directory
4) x-systemd.requires-mounts-for=/var here parameter means /var/log directory can not be mounted until /var directory has been mounted
)
# authselect disable-feature with-fingerprint
# authselect check
Current configuration is valid.
# cat /etc/pam.d/fingerprint-auth
# Generated by authselect on Wed Feb 22 22:22:22 2022
# Do not modify this file manually.
在本地局域网络中,各个设备的网卡都有自己的 ARP 缓存表,用于记录局域网中各个设备 IP 地址和 MAC 地址的对应关系。
# arp -d 192.168.0.1
(补充:这里以从本地 ARP 缓存表清楚 IP 地址 192.168.0.1 的 ARP 缓存为例)
# ping 192.168.0.1
(
补充:
1) 这里以获取 192.168.0.1 的 ARP 缓存为例。
2) 当本地尝试连接 IP 地址 192.168.0.1 时,首先发生 ARP 报文询问 IP 地址 192.168.0.1 的 MAC 地址获得 ARP 缓存。如果此缓存长期没有被使用则会自动删除。如果记录 ARP 缓存过多,那旧的 ARP 缓存会被有限删除
)