Static IP

How to Change the Static IP Address of a Windows Domain Controller

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Whether you are re-IPing a subnet or moving a server to a new VLAN, changing a Domain Controller’s IP address requires more than just updating the NIC settings. If DNS records don’t update correctly, users won’t be able to log in, and replication will fail.

Prerequisites

  • Credentials: You must be a member of the Domain Admins group.
  • Access: Log on locally to the system console. If you lose network connectivity during the change, you may need to boot into DSRM to recover.

Step-by-Step: Changing the IP Address

  1. Open Network Connections: Right-click My Network Places (or Network in newer versions) and click Properties.
  2. Edit Adapter: Right-click your Local Area Connection and select Properties.
  3. TCP/IP Settings: Double-click Internet Protocol (TCP/IP).
  4. Update Addresses:
    • Enter the new IP address, Subnet mask, and Default gateway.
    • Update the Preferred and Alternate DNS servers.
    • Note: Usually, a DC points to itself (127.0.0.1) or a partner DC for DNS.
  5. WINS (Optional): If your environment still uses WINS, click Advanced > WINS tab and update any static WINS server entries.
  6. Apply: Click OK until all dialog boxes are closed.

Critical Step: Post-Change Registration

Once the IP is changed, Windows needs to tell the rest of the domain where the DC is now located. Do not skip these commands.

Open a Command Prompt and run:

  1. Register DNS Records:DOSipconfig /registerdns This forces the DC to update its ‘A’ (Host) record in DNS.
  2. Fix Service Records:DOSdcdiag /fix This ensures that vital SRV records (which clients use to find the DC) are updated to point to the new IP.

Potential Pitfalls: Mapped Drives and Hardcoded IPs

Changing the IP settings won’t affect shared permissions, but it will break any connection made via IP address rather than hostname.

  • Avoid This: net use g: \\192.168.0.199\data (This breaks after the change).
  • Do This: net use g: \\DC1\data (This continues to work regardless of the IP).

The LazyAdmin Lesson: Always use DNS names (Hostnames) for your resources. It saves you from manual updates every time a server moves!

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