我正在尝试在 VPN 中设置 CentOS 7 DNS 服务器。我无法让 VPN 子网（不同子网）中的设备 ping 服务器。我可以让 ping 在服务器（同一子网）之间工作
当我运行时，tcpdump -nvi eth1 icmp我可以看到以下内容：
10.4.1.21执行 ping操作时10.4.1.2：
10:26:58.348366 IP (tos 0x0, ttl 64, id 20006, offset 0, flags [DF], proto ICMP (1), length 84)
10.4.1.21 > 10.4.1.2: ICMP echo request, id 17034, seq 1, length 64
10:26:58.348438 IP (tos 0x0, ttl 64, id 39037, offset 0, flags [none], proto ICMP (1), length 84)
10.4.1.2 > 10.4.1.21: ICMP echo reply, id 17034, seq 1, length 64
10:26:59.348266 IP (tos 0x0, ttl 64, id 20913, offset 0, flags [DF], proto ICMP (1), length 84)
10.4.1.21 > 10.4.1.2: ICMP echo request, id 17034, seq 2, length 64
10:26:59.348325 IP (tos 0x0, ttl 64, id 39998, offset 0, flags [none], proto ICMP (1), length 84)
10.4.1.2 > 10.4.1.21: ICMP echo reply, id 17034, seq 2, length 64
10:27:00.348248 IP (tos 0x0, ttl 64, id 21633, offset 0, flags [DF], proto ICMP (1), length 84)
10.4.1.21 > 10.4.1.2: ICMP echo request, id 17034, seq 3, length 64
10:27:00.348306 IP (tos 0x0, ttl 64, id 40058, offset 0, flags [none], proto ICMP (1), length 84)
10.4.1.2 > 10.4.1.21: ICMP echo reply, id 17034, seq 3, length 64
但是，当10.10.79.34我 ping时10.4.1.2，我看到的都是请求，没有回复
10:32:12.225281 IP (tos 0x0, ttl 127, id 3592, offset 0, flags [none], proto ICMP (1), length 60)
10.10.79.34 > 10.4.1.2: ICMP echo request, id 1, seq 78, length 40
10:32:17.250644 IP (tos 0x0, ttl 127, id 3593, offset 0, flags [none], proto ICMP (1), length 60)
10.10.79.34 > 10.4.1.2: ICMP echo request, id 1, seq 79, length 40
10:32:22.129885 IP (tos 0x0, ttl 127, id 3594, offset 0, flags [none], proto ICMP (1), length 60)
10.10.79.34 > 10.4.1.2: ICMP echo request, id 1, seq 80, length 40
10:32:27.389271 IP (tos 0x0, ttl 127, id 3595, offset 0, flags [none], proto ICMP (1), length 60)
10.10.79.34 > 10.4.1.2: ICMP echo request, id 1, seq 81, length 40
10:32:32.149386 IP (tos 0x0, ttl 127, id 3596, offset 0, flags [none], proto ICMP (1), length 60)
10.10.79.34 > 10.4.1.2: ICMP echo request, id 1, seq 82, length 40
10:32:37.269775 IP (tos 0x0, ttl 127, id 3597, offset 0, flags [none], proto ICMP (1), length 60)
10.10.79.34 > 10.4.1.2: ICMP echo request, id 1, seq 83, length 40
10:32:42.157175 IP (tos 0x0, ttl 127, id 3598, offset 0, flags [none], proto ICMP (1), length 60)
10.10.79.34 > 10.4.1.2: ICMP echo request, id 1, seq 84, length 40
我觉得 CentOS 服务器正在吞噬请求。到目前为止，我在日志中找不到任何有用的信息。我已经关闭了防火墙。
的笔记本电脑10.10.79.34能够 ping 到 的网关10.4.1.1。