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How to get a DC IP address?

Published in Network Administration 3 mins read

To get the IP address of a Domain Controller (DC), you can use the nslookup command-line tool. Here's a step-by-step guide:

Using nslookup to Find a DC IP Address

Here's a step-by-step guide on how to find the IP address of your Domain Controller using nslookup.

  1. Open Command Prompt:

    • Click Start, then click Run.
    • In the Open box, type cmd and press Enter to open the command prompt.

  2. Start nslookup:

    • Type nslookup and press Enter.

  3. Set Query Type:

    • Type set type=all and press Enter. This configures nslookup to retrieve all record types for a query.

  4. Query for DC Information:

    • Type the following command, replacing Domain_Name with your actual domain name:
      \_ldap._tcp.dc._msdcs.Domain_Name and then press Enter.

    • Example: If your domain name is example.com, the command would look like this:
      \_ldap._tcp.dc._msdcs.example.com

    • This command queries the DNS server for Service Location (SRV) records related to the Domain Controller. The output will display various information, including the hostname of the Domain Controller and, crucially, the IP address.

  5. Analyze the Output: The output from nslookup will provide information.

    • Look for the lines that start with name = <DC Hostname>. and Address: This is where the IP address of the Domain Controller will be listed.

Understanding the Command

  • \_ldap._tcp.dc._msdcs.: This part of the command specifies the DNS SRV record you are looking for. It's used by clients to locate a Domain Controller for the specified domain.
  • Domain_Name: Replace this with the actual domain name.
  • nslookup: A command-line tool for querying DNS servers.
  • set type=all: Configures nslookup to display all record types instead of just the A record.

Example

Suppose the output after executing the command was something similar to this:

\_ldap._tcp.dc._msdcs.example.com
        primary name server = dc1.example.com
        responsible mail addr = hostmaster.example.com
        serial  = 10435
        refresh = 900 (15 mins)
        retry   = 600 (10 mins)
        expire  = 86400 (1 day)
        default TTL = 3600 (1 hour)
\_ldap._tcp.dc._msdcs.example.com      SRV service location:
          priority       = 0
          weight         = 100
          port           = 389
          svr hostname   = dc1.example.com
dc1.example.com  internet address = 192.168.1.10

In the above output, 192.168.1.10 is the IP address of the domain controller.

Tips

  • Ensure you are connected to a network that has access to your domain's DNS server.
  • If your domain has multiple DCs, this query might return multiple results.
  • This approach leverages DNS SRV records, which is the standard way for clients to locate domain controllers on a network.

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