![本地网络计算机DNS解析速度慢](https://linux22.com/image/1540812/%E6%9C%AC%E5%9C%B0%E7%BD%91%E7%BB%9C%E8%AE%A1%E7%AE%97%E6%9C%BADNS%E8%A7%A3%E6%9E%90%E9%80%9F%E5%BA%A6%E6%85%A2.png)
我刚刚重建了我的桌面并构建了一个媒体服务器(均为 Windows 10 企业版)。但是,当我发出命令ping
、远程桌面或尝试通过主机名访问本地媒体服务器的网络共享时,我遇到了很大的延迟。使用 IP(v4 或 v6)跳过 DNS 查找没有延迟。我能够确认这是一个 DNS 问题nslookup
(结果如下)。
ipconfig /all
显示活动DNS服务器的相关输出:
DNS Servers . . . . . . . . . . . : 2600:6c44:c7f:ec25:9610:3eff:fe92:db0f
192.168.1.1
ping
按主机名 (第一个结果出现前延迟约 6 秒):
Pinging media [fe80::f443:381c:3440:800e%25] with 32 bytes of data:
Reply from fe80::f443:381c:3440:800e%25: time=1ms
Reply from fe80::f443:381c:3440:800e%25: time=5ms
Reply from fe80::f443:381c:3440:800e%25: time=1ms
Reply from fe80::f443:381c:3440:800e%25: time=2ms
ping
通过 IPv4(第一个结果之前没有延迟):
Pinging 192.168.1.5 with 32 bytes of data:
Reply from 192.168.1.5: bytes=32 time=1ms TTL=128
Reply from 192.168.1.5: bytes=32 time=1ms TTL=128
Reply from 192.168.1.5: bytes=32 time=1ms TTL=128
Reply from 192.168.1.5: bytes=32 time=3ms TTL=128
ping
通过 IPv6(第一个结果之前无延迟):
Pinging 2600:6c44:c7f:ec25:d0c2:66e:1d06:f61f with 32 bytes of data:
Reply from 2600:6c44:c7f:ec25:d0c2:66e:1d06:f61f: time<1ms
Reply from 2600:6c44:c7f:ec25:d0c2:66e:1d06:f61f: time<1ms
Reply from 2600:6c44:c7f:ec25:d0c2:66e:1d06:f61f: time<1ms
Reply from 2600:6c44:c7f:ec25:d0c2:66e:1d06:f61f: time<1ms
nslookup
使用默认 IPv6 DNS 服务器的主机名 (超时):
nslookup media
Server: 2600-6c44-0c7f-ec25-9610-3eff-fe92-db0f.dhcp6.chtrptr.net
Address: 2600:6c44:c7f:ec25:9610:3eff:fe92:db0f
DNS request timed out.
timeout was 2 seconds.
DNS request timed out.
timeout was 2 seconds.
*** Request to 2600-6c44-0c7f-ec25-9610-3eff-fe92-db0f.dhcp6.chtrptr.net timed-out
切换到 IPv4 DNS 服务器并发出nslookup
(超时):
> server 192.168.1.1
Default Server: lambic
Address: 192.168.1.1
> media
Server: lambic
Address: 192.168.1.1
DNS request timed out.
timeout was 2 seconds.
DNS request timed out.
timeout was 2 seconds.
*** Request to lambic timed-out
答案1
我启动了 Wireshark 进行仔细查看,发现如下 DNS 请求:
Standard query A media.MyEmployer.net
Standard query AAAA media.MyEmployer.net
media
我只是在请求中指定了域名,但MyEmployer.net
域名被附加了。这告诉我它与我的工作 VPN 有关,尽管我并没有积极使用它。
查看网络适配器中的高级 TCP/IP 设置,我发现附加了一个 DNS 后缀:
MyEmployer.net
这似乎是由我们的 Cisco VPN 客户端添加的,因此用户不必为他们想要连接的任何资产指定公司域(即用户体验改进)。删除 DNS 后缀后,请求不再发送到域,并且得到快速解决。