How to use local as a Top-Level Domain in vCloud Availability appliances

Products

• VMware Cloud Director

Issue/Introduction

This article provides information on how to add the local domain to the search domain list for each vCloud Availability appliance.

Environment

VMware Cloud Director Availability 4.x
VMware vCloud Availability 3.0.x
VMware vCloud Availability 3.5.x

Resolution

The local domain is a special pseudo top-level domain which is reserved for relatively small environments that use mDNS, defined in RFC 6762 - Multicast DNS. Alternatively, in special cases, the name resolution of .local names can also be managed using LLMNR, defined in RFC 4792 - Link-local Multicast Name Resolution (LLMNR).

The network management in all vCloud Availability appliances are based on the systemd network stack, which supports both mDNS and LLMNR. mDNS and LLMNR are turned off by default and local domains are not expected to be resolved via DNS. However if your DNS server is capable of resolving .local names, you need to explicitly add local to the list of search domains on each vCloud Availability appliance. Otherwise the name resolution of local names is going to fail.

VMware vCloud Availability 3.x

Currently, in vCloud Availability 3.x, adding local to the domain search list has to be performed manually:

1. SSH to the vCloud Availability appliance.
2. Navigate to the /etc/systemd/network/ directory.
3. Take a backup of the 10-eth0.network file:

cp 10-eth0.network 10-eth0.network.bak

4. If your DNS settings were manually configured, use a text editor such as vi to delete the following line from 10-eth0.network:

Domains=example.local

5. Navigate to the /etc/systemd/ directory.
6. Take a backup of the resolved.conf file:

cp resolved.conf resolved.conf.bak

7. Use text editor to add the following line to the [Resolve] section of resolved.conf:

Domains=local example.local
Note: As well as including the local domain, search domains must be separated by space without a leading dot.

8. Optionally, you can add the following lines to the [Resolve] section of resolved.conf if you wish to control the LLMNR and mDNS settings:

LLMNR=false
MulticastDNS=false

9. To apply these changes restart the following services:

systemctl restart systemd-networkd systemd-resolved
Note: This may lead to a temporary network outage on the appliance while the services restart.

VMware Cloud Director Availability 4.x

From VMware Cloud Director Availability 4.0 onwards, adding local to the domain search list can be done via the appliance management portal:

1. In a browser, navigate to the Cloud Director Availability appliance management portal.
2. Log into the portal with root user credentials.
3. In the left pane, click Configuration.
4. Go to Appliance settings > Network and click Edit.
5. In the Domain Search Path field, enter the local domain and the search domains.

Note: The search domains must must not have a leading dot and each entry must be followed by a comma and separated by a space.
Example: local, example.local

6. Click Apply.

Additional Information

• For more information, see RFC 6762 - Multicast DNS.
• For more information, see RFC 4792 - Link-local Multicast Name Resolution (LLMNR).