系统无法到达一个特定的 IP 地址 (41.215.xxx.1)

Question

好吧，这让我发疯了。

我有一台 RHEL 7 机器，几天前能够到达该目标 IP。它的 LAN 邻居可以看到远程主机，因此网络之间的路由良好。查看 IP 路由表、路由缓存和规则，没有任何异常情况可能导致问题。

default via 172.31.16.1 dev eth0 proto static metric 100
172.31.16.0/20 dev eth0 proto kernel scope link src 172.31.16.32 metric 100

# ip rule show
0:      from all lookup local
32766:  from all lookup main
32767:  from all lookup default

# ip route get 41.215.xxx.1
41.215.xxx.1 via 172.31.16.1 dev eth0 src 172.31.16.32
    cache

盒子上启用了 ICMP，可以 ping 其他 IP 地址。

PING 41.215.xxx.13 (41.215.xxx.13) 56(84) bytes of data.
64 bytes from 41.215.xxx.13: icmp_seq=1 ttl=39 time=130 ms
64 bytes from 41.215.xxx.13: icmp_seq=2 ttl=39 time=130 ms
64 bytes from 41.215.xxx.13: icmp_seq=3 ttl=39 time=130 ms
64 bytes from 41.215.xxx.13: icmp_seq=4 ttl=39 time=130 ms
64 bytes from 41.215.xxx.13: icmp_seq=5 ttl=39 time=130 ms

--- 41.215.xxx.13 ping statistics ---
5 packets transmitted, 5 received, 0% packet loss, time 4004ms
rtt min/avg/max/mdev = 130.145/130.245/130.399/0.406 ms
# ping 41.215.xxx.1 -c 5
PING 41.215.xxx.1 (41.215.xxx.1) 56(84) bytes of data.

--- 41.215.xxx.1 ping statistics ---
5 packets transmitted, 0 received, 100% packet loss, time 3999ms

因此，如上所示，到达此目的地的数据包丢失率为 100%。

traceroute to 41.215.xxx.1 (41.215.xxx.1), 30 hops max, 60 byte packets
 1  * * *
 2  * * *
 3  * * *
 4  * * *
 5  * * *
 6  * * *
 7  * * *
 8  * * *
 9  * * *
10  * * *
11  * * *
12  * * *
13  * * *
14  * * *
15  * * *
16  * * *
17  * * *
18  * * *
19  * * *
20  * * *
21  * * *
22  * * *
23  * * *
24  * * *
25  * * *
26  * * *
27  * * *
28  * * *
29  * * *
30  * * *

tshark 捕获不会捕获任何发往目标 IP 地址的信息。数据包甚至显然没有被创建，或者没有通过盒子上的唯一接口。是的，这听起来可能很疯狂 :)

eth0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 9001
        inet 172.31.16.32  netmask 255.255.240.0  broadcast 172.31.31.255
        ether 06:b1:d4:07:4e:14  txqueuelen 1000  (Ethernet)
        RX packets 364293720  bytes 168772961614 (157.1 GiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 473934683  bytes 95572128708 (89.0 GiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

任何指示将不胜感激。