arpd命令是一个用于收集免费ARP信息的守护进程。它将收集到的信息保存在磁盘上或者在需要时，提供给内核用户用于避免多余的ARP广播
常用选项-l：将ARP数据库输出到标准输出设备并退出-f：指定读取和加载arpd数据库的文本文件-b：指定arpd数据库文件，默认位置为"/var/lib/arpd.db"-a：指定目标被认为死掉前查询的次数-k：禁止通过内核发送广播查询-n：设定缓冲失效时间案例：
root@uk8s:~# arpd
db_open: No such file or directory
root@uk8s:~# which arpd
/usr/sbin/arpd
root@uk8s:~# arpd --help
arpd: invalid option -- '-'
Usage: arpd [ -lkh? ] [ -a N ] [ -b dbase ] [ -B number ] [ -f file ] [ -n time ] [-p interval ] [ -R rate ] [ interfaces ]
root@uk8s:~# arpd -b /var/tmp/arpd.db
root@uk8s:~# arpd -l -b /var/tmp/arpd.db
#Ifindex IP MAC
2 192.168.10.2 00:50:56:ee:57:d8
2 192.168.10.16 00:0c:29:51:7d:78
5 10.233.75.35 b6:68:04:9d:68:95
5 10.233.75.131 FAILED: 13sec ago
7 10.233.75.31 02:7f:30:ba:60:e5
15 10.233.75.57 b2:43:0b:aa:c6:c3
16 10.233.75.82 8e:27:f5:5c:69:c9
17 10.233.75.51 2a:2e:b7:bf:7c:db
20 10.233.75.52 4e:ab:fd:c4:28:f3
21 10.233.75.83 32:de:6d:6f:45:e1
22 10.233.75.66 d2:28:71:ca:74:80
24 10.233.75.60 26:c5:b9:35:80:a3
25 10.233.75.95 22:3d:19:8f:58:a4
2 192.168.10.1 00:50:56:c0:00:08
8 10.233.75.43 2a:36:fb:b8:d8:f8
10 10.233.75.105 e6:78:e9:fd:c9:fa
11 10.233.75.28 12:71:6c:62:8b:8c
14 10.233.75.33 5e:09:54:fc:3d:6f
19 10.233.75.44 0a:f1:18:97:98:76
20 10.233.75.153 FAILED: 14sec ago
22 10.233.75.107 FAILED: 14sec ago
28 10.233.75.23 c2:b9:9a:ea:83:ca
root@uk8s:~# arpd -l -b /var/tmp/arpd.db -a 3 -k ens33
#Ifindex IP MAC
2 192.168.10.2 00:50:56:ee:57:d8
2 192.168.10.16 00:0c:29:51:7d:78
2 192.168.10.1 00:50:56:c0:00:08
