CUCM - DHCP

[Cyon38]

Hello all.

We just installed a new Cisco Cisco Unified CM server and 50 Cisco phones. I notice that the DHCP services stop every now or other day. I need to restart the DHCP services to get the phones to work. I have spoken to the ISP and they said, I need to create a new DHCP Server with Option 150.

What OS do I use? Windows server, Linux or can I use our firewall?

[jrsteele21 · Accepted solution]

You can create a DHCP server with windows, linux, some firewalls and even a router if you want.  The phones look for option 150 after connecting to DHCP and getting an IP Address.  Option 150 tells the phones where to go to get their installation files.  Option 150 will point to the IP address of the CUCM.

[Nithin Eluvathingal · Accepted solution]

I don’t recommend using the DHCP service on the CUCM. Instead, I prefer to run it on any network device if there is no dedicated DHCP server. Option 150 IP is the TFTP address you define on the DHCP for the phone to download the configuration files and register. If this is not configured, the phones won’t register unless you define them manually. Did you set the TFTP address on these phones manually?

You can run the DHCP on any server you like. The only thing you cannot skip is the Option 150, which will be the IPs of CUCM nodes that have TFTP service activated