Domain wont resolve to IP

[NoS.]

Hi guys, I'm using Apache 2.0 .
I've set up apache for 3 of my domains. Each domain has its own virtual IP address. Everything works perfect at first, but right now... All of a sudden, one domain does not resolve to IP address anymore, i couldn't access it by going http://www.domain2.com, ping, nslookup does not work either.
The rest of the domains works fine, and they all have the same apache configuration settings.
I'm confused, and have been trying to find out why this is happening, and how to get my site back online.
Please help.

The following is my httpd.conf

<VirtualHost 70.85.8.43:80>
ServerName www.domain1.com
ServerAlias domain1.com
ServerAdmin webmaster@domain1.com

HostnameLookups Off

DocumentRoot /home/virtual/www.domain1.com/html
CustomLog logs/www.domain1.com combined
ErrorDocument 403 http://www.domain1.com
ErrorDocument 404 http://www.domain1.com
</VirtualHost>

<VirtualHost 70.85.8.43:80>
ServerName www.domain2.com
ServerAlias domain2.com
ServerAdmin webmaster@domain2.com

HostnameLookups Off

DocumentRoot /home/virtual/www.domain2.com/html
CustomLog logs/www.domain2.com combined
ErrorDocument 403 http://www.domain2.com
ErrorDocument 404 http://www.domain2.com
</VirtualHost>

<VirtualHost 70.85.8.43:80>
ServerName www.domain3.com
ServerAlias domain3.com
ServerAdmin webmaster@domain3.com

HostnameLookups Off

DocumentRoot /home/virtual/www.domain3.com/html
CustomLog logs/www.domain3.com combined
ErrorDocument 403 http://www.domain3.com
ErrorDocument 404 http://www.domain3.com
</VirtualHost>

Thanks,
Nos.

[depitsho]

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[depitsho]

hi,
i want to tell you that i think that you must put NameVirtualHost in the beginning in httpd.conf because you have one address and for <Virtual Host your domain>.And you must verify your dns configuration if is good. You can use dig it is very simple.