3

I just rebuilt my desktop and built a media server (both Windows 10 enterprise). However, I'm experiencing a large delay when I issue a ping command, remote desktop or try to access a network share of the local media server by host name. Using an IP (v4 or v6) to skip the DNS lookup has no delay. I was able to confirm this is a DNS issue with an nslookup (results are below).

Relevant output of ipconfig /all showing active DNS servers:

   DNS Servers . . . . . . . . . . . : 2600:6c44:c7f:ec25:9610:3eff:fe92:db0f
                                       192.168.1.1

ping by host name (~6 second delay before first result):

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 by IPv4 (no delay before first result):

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 by IPv6 (no delay before first result):

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 of hostname using the default IPv6 DNS server (times out):

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

Switching to the IPv4 DNS server and issuing an nslookup (times out):

> 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
  • There is likely no DNS record for "media" or any other computer on your network. That would require your ISPs modem/router to add DNS entries in to it's cache for you. Not likely. You're likely only resolving "media" to its IP via netbios. Netbios name resolution is usually pretty quick. My suggestion is to first disable IPv6 on the media machine. See if it helps. You may just need to access it by IP. Not a big deal really on a small home network. You could also add a HOSTS file entry if it's really bothering you. – Appleoddity Sep 10 '17 at 5:32
  • I was originally using a hosts file entry which worked well for everything except mapping a network drive. For some reason that process would still end up doing a lookup and would prevent me from defining the drive. – Justin Helgerson Sep 10 '17 at 13:31
1

I fired up Wireshark to get a closer look and found DNS requests such as:

Standard query A media.MyEmployer.net
Standard query AAAA media.MyEmployer.net

I was only specifying media in my requests, but the MyEmployer.net domain was being appended. This told me it was related to my work VPN even though I wasn't actively using it.

Looking at the advanced TCP/IP settings in my network adapter I found there was a DNS suffix being appended:

MyEmployer.net

This appears to be added by our Cisco VPN client so users don't have to specify the company domain for any assets they want to connect to (i.e. user experience improvement). After removing the DNS suffix requests were no longer being sent to the domain and were resolved quickly.

| improve this answer | |
  • Ahh. Nice. I have experience with this, unfortunately the VPN client will re-add the domains as soon as you connect again. – Appleoddity Sep 10 '17 at 13:42

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.