我在为我的一台服务器分配新地址时遇到了问题，每次我想添加新地址时，它都说该地址已被使用。所以我现在要做的是使用 arp 工具来查看哪些 ips 未被使用。
我注意到，无论我 ping 多少个不同的地址，然后使用 arp，我都会得到与网关相同的 MAC 地址。我的问题是，首先，这是正常现象吗？其次，我如何找到未使用的 IP，还有其他想法吗？
[user@swarm01 ~]$ ping 192.168.123.129
PING 192.168.123.129 (192.168.123.129) 56(84) bytes of data.
^C
--- 192.168.123.129 ping statistics ---
2 packets transmitted, 0 received, 100% packet loss, time 1001ms
[user@swarm01 ~]$ arp
Address HWtype HWaddress Flags Mask Iface
192.168.123.126 ether 16:12:9c:31:73:fa C eth0
192.168.123.59 ether dc:a9:04:94:1e:c9 C eth0
192.168.123.129 ether b4:0c:25:3f:e8:11 C eth0
192.168.123.128 ether b4:0c:25:3f:e8:11 C eth0
192.168.123.127 ether 4c:66:41:2e:4e:9c C eth0
gateway ether b4:0c:25:3f:e8:11 C eth0
[user@swarm01 ~]$ ping 192.168.123.130
PING 192.168.123.130 (192.168.123.130) 56(84) bytes of data.
^C
--- 192.168.123.130 ping statistics ---
3 packets transmitted, 0 received, 100% packet loss, time 2002ms
[user@swarm01 ~]$ arp
Address HWtype HWaddress Flags Mask Iface
192.168.123.126 ether 16:12:9c:31:73:fa C eth0
192.168.123.59 ether dc:a9:04:94:1e:c9 C eth0
192.168.123.129 ether b4:0c:25:3f:e8:11 C eth0
192.168.123.130 ether b4:0c:25:3f:e8:11 C eth0
192.168.123.128 ether b4:0c:25:3f:e8:11 C eth0
192.168.123.127 ether 4c:66:41:2e:4e:9c C eth0
gateway ether b4:0c:25:3f:e8:11 C eth0
[user@swarm01 ~]$ ping 192.168.123.131
PING 192.168.123.131 (192.168.123.131) 56(84) bytes of data.
^C
--- 192.168.123.131 ping statistics ---
4 packets transmitted, 0 received, 100% packet loss, time 3001ms
[user@swarm01 ~]$ arp
Address HWtype HWaddress Flags Mask Iface
192.168.123.131 ether b4:0c:25:3f:e8:11 C eth0
192.168.123.126 ether 16:12:9c:31:73:fa C eth0
192.168.123.59 ether dc:a9:04:94:1e:c9 C eth0
192.168.123.129 ether b4:0c:25:3f:e8:11 C eth0
192.168.123.130 ether b4:0c:25:3f:e8:11 C eth0
192.168.123.128 ether b4:0c:25:3f:e8:11 C eth0
192.168.123.127 ether 4c:66:41:2e:4e:9c C eth0
gateway ether b4:0c:25:3f:e8:11 C eth0