Sorry if it is very basic question. I was following basic environment setup on a centos 7 compute node and it says to configure the external network without an IP. How can ping http://openstack.org , work as suggested on the verification section if an IP is not set for the external network ?

I'm following the juno install guide for openstack

The external interface uses a special configuration without an IP address assigned to it. Configure the second interface as the external interface:

Replace INTERFACE_NAME with the actual interface name. For example, eth1 or ens224.

Edit the /etc/sysconfig/network-scripts/ifcfg-INTERFACE_NAME file to contain the following:

Do not change the HWADDR and UUID keys.

DEVICE=INTERFACE_NAME
TYPE=Ethernet
ONBOOT="yes"
BOOTPROTO="none"`