How to change the DNS servers for an LWS domain

Procédure

Objective

This guide explains how to change the DNS servers of a domain name registered with LWS from your customer area.

This action allows you to designate a new authoritative DNS zone for your domain.

Prerequisites

Before changing DNS servers, check the following points:

• You have access to your LWS customer area;
• You know which new DNS servers to use;
• The new DNS zone has already been created by the new provider;
• Web and e-mail services are already configured in this new DNS zone;
• you have checked that all the necessary records are present.

Recommended checks before changing

Before validating a DNS change, make sure that the new DNS zone contains at least :

• website records ;
• the e-mail records ;
• any sub-domains used;
• any necessary security or validation records.

When is it really necessary to change DNS servers?

Changing DNS servers is useful when you want to entrust the complete management of the DNS zone to another service provider.

Examples include

• use of an external DNS provider ;
• complete transfer of DNS management to another platform;
• using a service that explicitly asks you to replace the domain's DNS servers.

Warning: this is not always the right solution.

In some cases, it is better to change only one or more records in the current DNS zone, without changing the domain's DNS servers.

For example

• you want to point the site to an external service such as Wix;
• but you want to keep the current email service.

In this case, it is often preferable to modify only certain records in the current DNS zone, rather than changing all the DNS servers. This avoids having an unnecessary impact on the other services in the domain.

Procedure for changing DNS servers

Step 1. Log in to your LWS customer area

Step 2. Open the management of the domain concerned by clicking on the corresponding Manage button.

Step 3. Access the DNS server management function.

In the "Domain Management" section, click on the DNS Servers icon.

Step 4. Choose the configuration mode.

There are two possible options.

Option 1: Use the LWS default DNS servers

Choose this option if you want your domain to continue to use the DNS zone managed by LWS.

1. Indicate "No" to the question "Custom DNS configuration?
   

2. Click on the button: Validate

3. The default LWS DNS servers on your package will be automatically configured, so you don't need to do anything else.

Case 2: use other DNS servers

Choose this option if you want your domain to use another authoritative DNS zone (cPanel, Plesk, VPS, external service).

1. Indicate "Yes" to the question "Custom DNS configuration" (1)
   

2. Enter the new DNS servers supplied by your provider (2). Four locations are proposed, but only two are mandatory.

3. Check one last time that the new DNS zone contains all the necessary records.

4. Click on the button: Validate

Expected result

Once the change has been propagated :

• your domain will use the new DNS servers specified;
• The domain's DNS responses will now depend on the new DNS zone;
• The behaviour of the website, e-mails and other services will depend on the records in this new zone.

You should therefore not simply wait for "the site to point to the new hosting", but rather for the domain to start responding according to the new active DNS zone.

Propagation delay

It can take up to 24 hours for a DNS server change to be taken into account, sometimes longer depending on the DNS cache context.

During this time :

• some users may still see the old configuration ;
• others may already be using the new configuration;
• Behaviour may temporarily vary depending on the network or access provider.

This delay is normal.

Check that the change has been taken into account

After propagation, check :

• that the domain is responding correctly with the new DNS servers;
• that the website is working as expected;
• that emails are still working;
• that the important sub-domains are responding correctly;
• that the specific records required for your services are active.

The change is successful if the new DNS zone responds correctly and all the domain's services remain operational.

Common problems

The website or emails no longer work after the change

This can happen in two cases:

1. The new DNS zone is not configured correctly
The new DNS servers respond correctly, but the DNS zone to which they refer does not contain all the necessary records.

Examples :

• missing or incorrect web records ;
• e-mail records are missing ;
• sub-domains not recreated;
• technical records forgotten.

2. Services have not been migrated to the new infrastructure
Even if the new DNS zone is correct, the website or email service may not work if the content or services do not yet exist on the new target servers.

For example

• the domain points to a new hosting, but the site has not yet been installed there;
• the DNS zone contains new MX records, but the mailboxes have not been recreated at the new service provider;
• the site content, databases or e-mail accounts have not yet been migrated.

Check that

• the new DNS zone contains all the relevant records;
• the website is installed and operational on the intended target;
• e-mail boxes, redirections, aliases or mail services have been recreated if necessary;
• content and data have been migrated before the DNS change.

New DNS servers are refused during registration

In some cases, new DNS servers cannot be registered or are refused by the registry.

This can happen if :

• the DNS servers are not correctly configured to be authoritative on the domain ;
• the domain is not declared in the zone served by these DNS;
• the DNS server name does not correspond to a valid name or refers to a CNAME;
• the advertised IP address does not actually correspond to the DNS server;
• the registry applies additional technical rules depending on the domain extension.

For .lu domains, the DNS Luxembourg test tool can check their validity before you apply them.

If your DNS servers are rejected, contact the service provider who supplied the DNS to check that your domain can function correctly with these servers.

DNS servers use IP addresses deemed invalid by the registry

Some registries impose specific diversity or technical validity rules for DNS servers.

Depending on the extension concerned, a refusal may occur if :

• several DNS servers advertised use the same IP when the registry expects servers to be genuinely distinct ;
• the IPs provided do not respond correctly
• the configuration does not comply with the registry's technical controls.

This point depends on the registry and thedomain extension. We must therefore avoid generalising the rule to all extensions, but it is important to point out that a refusal may be due to a constraint specific to the registry.

DNS servers respond, but not for your domain

A DNS server may work technically without being correctly configured for your domain.

For example

• the server responds to DNS requests ;
• but it does not yet host the authoritative zone for your domain ;
• or it does not return the correct NS records for this domain.

In this case, the DNS change may fail or lead to a service interruption.

Check that

• the domain has been created on the new DNS ;
• the domain's DNS zone is published;
• the NS records returned correspond to the expected delegation.

I only wanted to change the website, not the entire domain configuration

In this case, a complete change of DNS servers may not be the right solution.

Changing the DNS servers may result in the entire DNS management of the domain being switched to another zone, and therefore impact :

• the website ;
• emails ;
• sub-domains ;
• certain technical records.

If your requirements only concern an external web service, it is often preferable to :

• keep the current DNS servers ;
• modify only the records required in the current DNS zone.

Example: point the site to a service like Wix while keeping the existing email service.

The domain is being transferred

During a domain transfer, it will not be possible to change the DNS servers.

In this case :

• you must make the change before starting the transfer ;
• or wait until the transfer is complete.

However, depending on the context, it may still be possible to modify the records of the DNS zone currently in use, without changing the entire delegation of DNS servers.

Propagation is not complete

After a DNS change, the behaviour of the domain may remain temporarily inconsistent:

• some users still see the old configuration ;
• others are already using the new configuration
• the site or emails may seem to be working irregularly depending on the network.

This does not necessarily mean that the configuration is wrong. You should first check that the propagation has been completed before concluding that there has been a fault.

The right thing to do before changing DNS

Before making any changes, ask yourself this question:

Do I need to change the entire DNS delegation for the domain, or just one or two records in the current DNS zone?

If you only need to change :

• the website ;
• a sub-domain ;
• a technical validation ;
• a specific external service ;

then a simple change to the DNS zone may be more appropriate and less risky than a complete change of DNS servers.

Conclusion

Changing a domain's DNS servers doesn't just change an isolated pointing: it can switch the entire domain to another DNS zone.

Before taking this action, you need to check that the new DNS zone is complete and correct, and that it supports all the services used, particularly web and email.

If your objective is limited to a single service, it may be preferable to modify only the current DNS zone rather than changing the DNS servers completely.