A work around the DNS is editing the /etc/hosts file and hard coding your servers there. Do you have access to this file? <div class="gmail_quote">On Mon, Jan 10, 2011 at 9:08 AM, Tapas Mishra <<a href="mailto:mightydreams@gmail.com">mightydreams@gmail.com</a>> wrote: <blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;"><div><div></div><div class="h5">On Mon, Jan 10, 2011 at 5:31 PM, Tapas Mishra <<a href="mailto:mightydreams@gmail.com">mightydreams@gmail.com</a>> wrote: > Hi all. > The problem I am reporting is not very clearly evident to me. > I have a virtualization setup where in I had configured in 4 virtual > machines (which serve 4 different websites) available to internet via > a > Reverse Proxy on the Host OS (bare metal) I use Ubuntu 10.04 64 bit > server edition and kvm for this setup. > > We have not changed any of the server configurations from past 6 > months since things were working properly without any problem on this > server. > The sites are available to people as > > > <a href="http://site1.myserver.com" target="_blank">http://site1.myserver.com</a> <-- No problem > <a href="http://site1.myserver.com/app1" target="_blank">http://site1.myserver.com/app1</a> <-- Gives problem till weekend there > was no problem > > <a href="http://site4.myserver.com" target="_blank">http://site4.myserver.com</a> <--Is also giving problem till this Sunday > 9 Jan there were no problem. > > Here are the error messages which I see in Apache logs > > Mon Jan 10 17:07:05 2011] [error] [client 172.21.100.250] proxy: DNS > lookup failure for: <a href="http://site4.myserver.com" target="_blank">site4.myserver.com</a> returned by / > [Mon Jan 10 17:07:06 2011] [error] [client 172.21.100.250] proxy: DNS > lookup failure for: <a href="http://site4.myserver.com" target="_blank">site4.myserver.com</a> returned by / > > and for <a href="http://site1.myserver.com/app1" target="_blank">site1.myserver.com/app1</a> also I get same error > > [Mon Jan 10 17:06:01 2011] [error] [client 172.21.100.250] proxy: DNS > lookup failure for: <a href="http://site1.myserver.com" target="_blank">site1.myserver.com</a> returned by /app1/ > [Mon Jan 10 17:06:01 2011] [error] [client 172.21.100.250] proxy: DNS > lookup failure for: <a href="http://site1.myserver.com" target="_blank">site1.myserver.com</a> returned by /app1/ > [Mon Jan 10 17:06:02 2011] [error] [client 172.21.100.250] proxy: DNS > lookup failure for: <a href="http://site1.myserver.com" target="_blank">site1.myserver.com</a> returned by /app1/ > > > How ever when some one tries to access <a href="http://site1.myserver.com" target="_blank">http://site1.myserver.com</a> there > is no error at all. > Also if I access <a href="http://site5.somebody_server.com" target="_blank">http://site5.somebody_server.com</a> (which is same as > <a href="http://site4.myserver.com" target="_blank">http://site4.myserver.com</a> pointing to same public IP) but on some body > elses server > then there is no problem at all and the site is very clearly visible. > > > Let me know what more should I look for I have no clue of this problem. > Because these error messages which I just report in this thread were > not at all present until today morning. > > > > -- > </div></div>Ok after having a long trouble shooting hours found the root cause my proxy pass entries look as follows ProxyPass /app1 <a href="http://192.168.1.3:8080/app1" target="_blank">http://192.168.1.3:8080/app1</a> ProxyPass / <a href="http://192.168.1.3" target="_blank">http://192.168.1.3</a> ProxyPassReverse /app1 <a href="http://192.168.1.3:8080/app1" target="_blank">http://192.168.1.3:8080/app1</a> ProxyPassReverse / <a href="http://192.168.1.3" target="_blank">http://192.168.1.3</a> If I use the entries as above then some one from internet is able to access the sites.But from within LAN people are unable to access it. How ever if I use ProxyPass /app1 <a href="http://site1.myserver.com:8080/app1" target="_blank">http://site1.myserver.com:8080/app1</a> ProxyPass / <a href="http://site1.myserver.com" target="_blank">http://site1.myserver.com</a> ProxyPassReverse /app1 <a href="http://site1.myserver.com:8080/app1" target="_blank">http://site1.myserver.com:8080/app1</a> ProxyPassReverse / <a href="http://site1.myserver.com" target="_blank">http://site1.myserver.com</a> then things work on LAN but from internet it is not accessible and errors are the ones I mentioned above in the thread. What can be a solution in this case as I do not have a DNS at my disposal I am simply not allowed to have one. Can some one suggest any thing? <div><div></div><div class="h5"> -- ubuntu-server mailing list <a href="mailto:ubuntu-server@lists.ubuntu.com">ubuntu-server@lists.ubuntu.com</a> <a href="https://lists.ubuntu.com/mailman/listinfo/ubuntu-server" target="_blank">https://lists.ubuntu.com/mailman/listinfo/ubuntu-server</a> More info: <a href="https://wiki.ubuntu.com/ServerTeam" target="_blank">https://wiki.ubuntu.com/ServerTeam</a> </div></div></blockquote></div>