neutron

vm can not ping outer world with domain name

Asked by yuanyangen

hi guys:
I am new to openstack , I deploy openstack folsom on three nodes as following:

http://docs.openstack.org/folsom/basic-install/content/index.html

I success create a instance, everything works well, in this vm ,I can ping others via ip, but when I use a domain name ,i got the following:
ubuntu@inception:~$ ping www.google.com
ping: unknown host www.google.com

of course, it is the dns problem, but I can't change the file /etc/resolv.conf in vm,cause it always change to the default one, the /etc/resolv.conf in the vm is like this:
nameserver 50.50.10.2
domain openstacklocal
search openstacklocal

in the vm ,i can ping 50.50.10.2, but in controller i can not ping to 50.50.10.2

I have the dnsmasq run on netwrok node:

network@network:~$ ps auxf | grep dns
network 32695 0.0 0.0 8104 928 pts/0 S+ 15:26 0:00 \_ grep --color=auto dns
nobody 15651 0.0 0.0 27540 1100 ? S Jun08 0:00 dnsmasq --no-hosts --no-resolv --strict-order --bind-interfaces --interface=tapb3e23716-ae --except-interface=lo --domain=openstacklocal --pid-file=/var/lib/quantum/dhcp/47d751a7-130e-412e-911a-d52525d83e21/pid --dhcp-hostsfile=/var/lib/quantum/dhcp/47d751a7-130e-412e-911a-d52525d83e21/host --dhcp-optsfile=/var/lib/quantum/dhcp/47d751a7-130e-412e-911a-d52525d83e21/opts --dhcp-script=/usr/bin/quantum-dhcp-agent-dnsmasq-lease-update --leasefile-ro --dhcp-range=set:tag0,50.50.10.0,static,120s
root 15652 0.0 0.0 27512 468 ? S Jun08 0:00 \_ dnsmasq --no-hosts --no-resolv --strict-order --bind-interfaces --interface=tapb3e23716-ae --except-interface=lo --domain=openstacklocal --pid-file=/var/lib/quantum/dhcp/47d751a7-130e-412e-911a-d52525d83e21/pid --dhcp-hostsfile=/var/lib/quantum/dhcp/47d751a7-130e-412e-911a-d52525d83e21/host --dhcp-optsfile=/var/lib/quantum/dhcp/47d751a7-130e-412e-911a-d52525d83e21/opts --dhcp-script=/usr/bin/quantum-dhcp-agent-dnsmasq-lease-update --leasefile-ro --dhcp-range=set:tag0,50.50.10.0,static,120s

In both controller and network , I also add the nameserver 8.8.8.8 into the file : /etc/resolv.conf

here is my question:
how could i solve this question
and why this situation happens?

Thanks in advance

yuanyangen

Question information

Language:
English Edit question
Status:
Answered
For:
neutron Edit question
Assignee:
No assignee Edit question
Last query:
Last reply:
Revision history for this message
Patrick Vinas (patrickvinas) said : 		#1

Your subnet is probably configured to provide 50.50.10.2 as the nameserver to instances that get IP via DHCP. You can verify that this is the case using the quantum CLI:

quantum subnet-show <subnet id>

will display, among other things:

...
dns_nameservers 50.50.10.2
...

You can change the nameservers in your subnet settings via command line:

quantum subnet-update <subnet-id> --dns-nameservers 8.8.8.8

Can you help with this problem?

Provide an answer of your own, or ask yuanyangen for more information if necessary.

To post a message you must log in.