How to add Avaya 242 option into DHCP Server

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You’re migrating/building a new DHCP 2012 server and find that 242 option does not exist within scope options.

Here is how to add:

1) Launch DHCP
2) Expand DHCP and right click IPV4
3) Click ‘Set Predefined Options’
4) Click Add

5) Type in details

Name: 242 Avaya
Data Type: String
Code: 242
Description: Avaya Phones

6) Click ok

7) In the string value, type your AVAYA string, for  for example: MCIPADD=,MCPORT=1719,HTTPSERVER=

8) Click OK

9) Revisit your Scope Options, scroll to the bottom and add

If you are running a DHCP HA (Failover), the scope will need to be added to the partner server, the settings will not replicate.


Export DHCP scopes via command

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1) netsh dhcp server <ipaddress> export all c:\dhcp-export.txt
2) Copy file dhcp-export.txt to destination server disk C

Run the below command if you wish to import into new DHCP server

3) netsh dhcp server import all c:\dhcp-export.txt

The scopes will be activated by default, as soon as you import. Disable them if required.

Don’t forget to configure switch if you have an IP helper

Clients not updating DNS settings from DHCP

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You have migrated your DHCP role to a different server. For example, from a Windows 2003 to a 2008 server and you have reconfigured the DNS entries so clients are issued with new DNS server addresses.

You have disabled the scopes on the old DHCP server and unauthorised the server as a DHCP server.

You find that your clients are being assigned ip addresses from the new DHCP server but the DNS entries are still set to the old ones.

This is an odd fix, but you will find that disabling the DHCP service or uninstalling DHCP from the old server, will resolve the issue.

Disable the DHCP server service from the old DHCP server and let us know how you get on with this fix by commenting below