在 10.0.0.1给 10.0.0.2发送一个icmp包，收到回复后，又互相发送了一个单播arp请求包，这是用来验证arp和ip映射的还是做什么的，怎么生成的？
系统环境ubuntu16 mininet平台 openvswitch交换机 两个主机是mininet里面模拟的
15:26:04.432530 00:00:00:00:00:01 > 00:00:00:00:00:02, ethertype IPv4 (0x0800), length 98: 10.0.0.1 > 10.0.0.2: ICMP echo request, id 2475, seq 1, length 64
15:26:04.433219 00:00:00:00:00:02 > 00:00:00:00:00:01, ethertype IPv4 (0x0800), length 98: 10.0.0.2 > 10.0.0.1: ICMP echo reply, id 2475, seq 1, length 64
15:26:09.435268 00:00:00:00:00:01 > 00:00:00:00:00:02, ethertype ARP (0x0806), length 42: Request who-has 10.0.0.2 tell 10.0.0.1, length 28
15:26:09.436621 00:00:00:00:00:02 > 00:00:00:00:00:01, ethertype ARP (0x0806), length 42: Request who-has 10.0.0.1 tell 10.0.0.2, length 28
15:26:09.436670 00:00:00:00:00:01 > 00:00:00:00:00:02, ethertype ARP (0x0806), length 42: Reply 10.0.0.1 is-at 00:00:00:00:00:01, length 28
15:26:09.436859 00:00:00:00:00:02 > 00:00:00:00:00:01, ethertype ARP (0x0806), length 42: Reply 10.0.0.2 is-at 00:00:00:00:00:02, length 28
15:27:17.005989 00:00:00:00:00:01 > 00:00:00:00:00:02, ethertype IPv4 (0x0800), length 98: 10.0.0.1 > 10.0.0.2: ICMP echo request, id 2480, seq 1, length 64
15:27:17.006772 00:00:00:00:00:02 > 00:00:00:00:00:01, ethertype IPv4 (0x0800), length 98: 10.0.0.2 > 10.0.0.1: ICMP echo reply, id 2480, seq 1, length 64
15:27:22.011634 00:00:00:00:00:01 > 00:00:00:00:00:02, ethertype ARP (0x0806), length 42: Request who-has 10.0.0.2 tell 10.0.0.1, length 28
15:27:22.012498 00:00:00:00:00:02 > 00:00:00:00:00:01, ethertype ARP (0x0806), length 42: Request who-has 10.0.0.1 tell 10.0.0.2, length 28
15:27:22.012517 00:00:00:00:00:01 > 00:00:00:00:00:02, ethertype ARP (0x0806), length 42: Reply 10.0.0.1 is-at 00:00:00:00:00:01, length 28
15:27:22.012661 00:00:00:00:00:02 > 00:00:00:00:00:01, ethertype ARP (0x0806), length 42: Reply 10.0.0.2 is-at 00:00:00:00:00:02, length 28
