Instance Fails to Reach or Resolve External Addresses

Problem

  • One or more instances on a network are failing to reach or resolve any external addresses and IPs, e.g.

~ # rpm -Uvh https://yum.postgresql.org/11/redhat/rhel-7-x86_64/pgdg-redhat-repo-latest.noarch.rpmRetrieving https://yum.postgresql.org/11/redhat/rhel-7-x86_64/pgdg-redhat-repo-latest.noarch.rpmcurl: (6) Could not resolve host: yum.postgresql.org; Unknown errorerror: skipping https://yum.postgresql.org/11/redhat/rhel-7-x86_64/pgdg-redhat-repo-latest.noarch.rpm - transfer failed
~ # ping www.google.com^C~ # ping 8.8.8.8PING 8.8.8.8 (8.8.8.8) 56(84) bytes of data.^C--- 8.8.8.8 ping statistics ---4 packets transmitted, 0 received, 100% packet loss, time 2999ms

Environment

  • Platform9 Managed OpenStack - All Versions

  • Neutron

Cause

The default security group is not applied and/or does not allow for outbound access to the targeted CIDR(s).

Resolution

  1. Edit the security groups for the instance.

  2. Edit the security group(s) if needed to allow for outbound access.

If a security group is applied which allows for outbound access and the instance is still unable to send outbound traffic – please refer to: Outbound Connectivity Failing for Instances on Tenant Network.

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Instance Fails to Reach or Resolve External AddressesProblemEnvironmentCauseResolution