Run trace route from guest vms, the result will yield to the point where packet drop is happening, could be a network acl rule issue, but tracert command can lead to some answers.
List running ports as well on VR, do a telnet to dns port on router from guest vm to verify for its response. Santhosh ________________________________________ From: Indra Pramana [in...@sg.or.id] Sent: Sunday, July 20, 2014 1:06 PM To: users@cloudstack.apache.org Cc: d...@cloudstack.apache.org Subject: Re: DNS service on VR not responding Hi Rafael, Good day to you, and thank you for your reply. Can't find anything wrong on dnsmasq.log / daemon.log, just some log entries related to DHCP, nothing on DNS. I masked the IP addresses since they are public. === Jul 20 16:21:51 r-2606-VM dnsmasq[3519]: DHCPDISCOVER(eth0) X.X.X.X 06:62:a8:01:13:37 Jul 20 16:21:51 r-2606-VM dnsmasq[3519]: DHCPOFFER(eth0) X.X.X.X 06:62:a8:01:13:37 Jul 20 16:21:51 r-2606-VM dnsmasq[3519]: DHCPREQUEST(eth0) X.X.X.X 06:62:a8:01:13:37 Jul 20 16:21:51 r-2606-VM dnsmasq[3519]: DHCPACK(eth0) X.X.X.X 06:62:a8:01:13:37 yyyyyy Jul 20 16:23:53 r-2606-VM dnsmasq[3519]: DHCPINFORM(eth0) X.X.X.X 06:43:4a:01:12:65 Jul 20 16:23:53 r-2606-VM dnsmasq[3519]: DHCPACK(eth0) X.X.X.X 06:43:4a:01:12:65 zzzzzz === Yes, the guest VMs are having difficulties resolving domains into IP addresses because of the problem on the VR's DNS server. $ host www.google.com X.X.X.X (where X.X.X.X is the IP address of the VR) ;; connection timed out; no servers could be reached However, from within the VR, I am able to resolve domains just fine. Any advise where can I start troubleshooting this? Looking forward to your reply, thank you. Cheers. On Sun, Jul 20, 2014 at 11:26 PM, Rafael Weingartner < rafaelweingart...@gmail.com> wrote: > Have you taken a look at dnsmasq.log in the VR ? > What do you mean with not responding? The addresses are not being resolved > to ip addresses? > > > On Sun, Jul 20, 2014 at 11:53 AM, Indra Pramana <in...@sg.or.id> wrote: > > > Dear all, > > > > All our guest VMs are having our virtual router (VR)'s IP address on > > /etc/resolv.conf. In the past two weeks, I just realised that the DNS > > service on the VR is not working, and doesn't respond to DNS queries from > > the DNS clients on the guest VM. > > > > I have tried to stop and start back the VR, but the problem persists. > > > > DHCP services seems to be running fine, only DNS services are not > working. > > From what I understand, both services are provided by dnsmasq, correct? > > > > Any advice on how can I resolve the problem? > > > > Looking forward to your reply, thank you. > > > > Cheers. > > > > > > -- > Rafael Weingärtner >
