
11-04-2007
|
|
|
|
Long pause before log in when not connected to domain - Vista Busi
Hi folks. Just wondering if anyone else is having this problem and if so,
how can I fix it. After joining my Vista laptop to the domain at work, the
login at home is really really slow. Almost 2 minutes. i'm guessing it is
looking for the DC but I don't know how to make it know that it really isnt'
there and speed up my boot time. Anyone? thanks.
I have found the information below but do not know how to apply what is
being said? If it is the correct answer can someone direct me in how these
chages are made.
I recently ran into a interesting issue where a Windows Vista machine would
wait for 2 minutes to login after the password was typed in. But it would
only occur when the laptop was connected to a network with internet access
that was not its normal domain network.
After hooking the laptop to a hub with another PC, i started Wireshark to
log all packets. After sifting through the data I found that it was
attempting to connect to the primary domain controller by domain name, and
consecutively trying to connect to all 5 secondary domain controllers by
domain name.
What I found was that the domain names were not pointing to the domain
servers across the internet, which would be dumb, but were trying to resolve
the domain using yahoo name servers which didn’t know the internal sub
domains. It was connecting to Yahoo’s name servers because that is who they
have hosting their external DNS for them. Yahoo’s name servers redirected the
connections to their main website instead because it was a catch-all address.
The problem is in three different places here.
Split DNS is being used - They are using a internal DNS server to resolve
their subdomains internally, but these subdomains are not known externally so
when they are remote they do not resolve properly.
A catch-all address is being used on yahoo’s name servers - This is causing
any unknown subdomains to be redirected to the main domain name. Which in
this case, is the main website which doesn’t house the domain server.
The requests are hitting yahoo’s firewall and it is dropping the packets
instead of sending a ICMP error message - This is causing the TCP connections
to hang for the default amount of time causing windows to wait before logging
in.
This problem is obviously caused by DNS issues. In order to remedy the
problem, I had to fix the broken split DNS issues.
To do this you have two options:
Remove the wildcard from DNS.
Redirect the problem subdomains to 127.0.0.1
Removing the wildcard from DNS is the preferred solution. This will cause
the DNS server to report “no such name” which will terminate the connection
before it is established.
If you cannot remove the wildcard from DNS then you will want to manually
make DNS records that point to 127.0.0.1
Such as:
subdomain1.example.com > 127.0.0.1
subdomain2.example.com > 127.0.0.1
This will cause the connection to redirect to your localhost when offsite
using global DNS. Your localhost will then report that connection unusable
which will terminate the connection right away.
The boot up times decreased by 75%!
From 2 minutes to 30 seconds. That is an improvement! The lesson here is to
make sure your DNS is correct.
|