I have a client who was acquired by a larger company. They still have their data servers connected to their previous Y domain, while they're being given laptops that operate on the X domain from the larger company. The users need to access mapped network drives still linked to the Y domain, which they do by saving credentials in Windows Credential Manager. However, whenever they try to open Word or Excel files from these mapped drives, it takes about 20-30 seconds, whereas older computers on the Y domain can open them instantly. This issue occurs even when the laptops are on the same LAN. Any ideas why this is happening? The servers are running on Windows Server 2022 and the clients are on Windows 11 24h2.
5 Answers
I’ve noticed that slow name resolution often happens if the old domain resources aren't mapped using the fully qualified domain name (FQDN), although this was never quite this bad. Also, check if there’s any DFS involved or if the DNS conditional forwarders are pointing to a sluggish DNS server from the old domain.
I’ve encountered a similar issue before when documents were created from templates located on a server that couldn’t be resolved in DNS. Make sure you can resolve the DNS name for any Company Y SMB server from Company X. Sometimes it helps to check if there’s a different SMB server listed as the template location. Interestingly, even if you resolve it to 127.0.0.1, it can fix the slow document opening problem.
Do you have any trusted network locations configured? It might be worth checking if the new mappings need to be added.
This issue seems DNS-related. Windows typically tries to reach servers using the FQDN of the new domain first, which can time out after 20-25 seconds before it switches to the old domain. Try mapping the drives using the IP address instead of the FQDN to see if that speeds things up.
I ran into a similar situation, but my difference was between hybrid joined and Entra joined devices using hybrid identities and cloud Kerberos trust for access. Be sure your drives are mapped via FQDN.
Seems like using nmap could provide some insights into this.