我使用系统板上的2个以太网接口，eth0 / eth1（usb到以太网），如下所示。
root@E3-RDP:~# ifconfig
eth0 Link encap:Ethernet HWaddr ae:a1:99:48:86:79
inet addr:10.10.0.171 Bcast:10.10.0.255 Mask:255.255.255.0
inet6 addr: fe80::aca1:99ff:fe48:8679/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:532 errors:0 dropped:0 overruns:0 frame:0
TX packets:18 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:36510 (36.5 KB) TX bytes:972 (972.0 B)
Interrupt:114
eth1 Link encap:Ethernet HWaddr 00:0e:c6:87:72:01
inet addr:10.10.0.176 Bcast:10.10.0.255 Mask:255.255.255.0
inet6 addr: fe80::20e:c6ff:fe87:7201/64 Scope:Link
UP BROADCAST MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:1 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:0 (0.0 B) TX bytes:94 (94.0 B)
lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope:Host
UP LOOPBACK RUNNING MTU:16436 Metric:1
RX packets:44 errors:0 dropped:0 overruns:0 frame:0
TX packets:44 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:3336 (3.3 KB) TX bytes:3336 (3.3 KB)
当我在PC上检查mac地址（eth0 / eth1）时，这些地址与以下相同。
C:\Users\andy>arp -a IP MAC ADDR Type
10.10.0.1 90-9f-33-a8-20-14 dynamic
10.10.0.171 ae-a1-99-48-86-79 dynamic
10.10.0.176 ae-a1-99-48-86-79 dynamic
10.10.0.186 60-a4-4c-35-1a-dd dynamic
我应该检查什么问题？
在我的系统上，ping测试（eth1）失败。
root@E3-RDP:~# ping -I eth1 10.10.0.173
PING 10.10.0.173 (10.10.0.173) from 10.10.0.176 eth1: 56(84) bytes of data.
From 10.10.0.176 icmp_seq=1 Destination Host Unreachable
From 10.10.0.176 icmp_seq=2 Destination Host Unreachable
From 10.10.0.176 icmp_seq=3 Destination Host Unreachable
From 10.10.0.176 icmp_seq=4 Destination Host Unreachable
From 10.10.0.176 icmp_seq=5 Destination Host Unreachable
From 10.10.0.176 icmp_seq=6 Destination Host Unreachable
^C
--- 10.10.0.173 ping statistics ---
7 packets transmitted, 0 received, +6 errors, 100% packet loss, time 6007ms
pipe 3
但是eth0的ping测试是可以的。
root@E3-RDP:~# ping 10.10.0.173
PING 10.10.0.173 (10.10.0.173) 56(84) bytes of data.
64 bytes from 10.10.0.173: icmp_seq=1 ttl=128 time=2.40 ms
64 bytes from 10.10.0.173: icmp_seq=2 ttl=128 time=0.327 ms
64 bytes from 10.10.0.173: icmp_seq=3 ttl=128 time=0.459 ms
64 bytes from 10.10.0.173: icmp_seq=4 ttl=128 time=0.727 ms
64 bytes from 10.10.0.173: icmp_seq=5 ttl=128 time=0.403 ms
64 bytes from 10.10.0.173: icmp_seq=6 ttl=128 time=0.528 ms
^C
--- 10.10.0.173 ping statistics ---
6 packets transmitted, 6 received, 0% packet loss, time 5000ms
rtt min/avg/max/mdev = 0.327/0.808/2.406/0.725 m
我认为无法识别的mac地址导致ping测试错误（eth1）。
谢谢。
USB适配器具有相同的MAC地址是一个常见问题。所有Mac地址必须唯一。下次不要再购买便宜的东西。