Troubleshooting Tip: Mitel IP Phones not getting an IP address when using DHCP Option 125

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Description	This article describes an issue where, when using the DHCP option 125 to get an IP address for the phones, a Malformed Packet Exception occurs.
Scope	FortiGate.
Solution	DHCP Options allow for the configuration of various parameters for DHCP servers, particularly for Mitel IP endpoints, which can use options 43 or 125 in compliance with recent reclassifications by the Internet Engineering Task Force. For detailed information about DHCP options, see RFC 2132, DHCP Options and BOOTP Vendor Extensions. Configuring the DHCP option 125 as in the following examples will lead to the error 'the Malformed Packet (Exception occurred)' on the DHCP Offer Packets. config option     edit 1         set code 125         set type string         set value "69643A697070686F6E652E6D6974656C2E636F6D, 73775F746674703D3130392E3135392E3230302E3234, 63616C6C5F7372763D3130392E3135392E3230302E3234, 647363703D3436763436733236"     next end  Or: config option     edit 1         set code 125         set type string         set value "id:ipphone.test.com, sw_tftp=108.167.20.14, call_srv=108.167.20.14 dscp=46v46s26"     next end Solution 1: To resolve the issue need to convert the String Value into the HEX Value. FortiGate does not support 'Encapsulated' data type for the 'Value Type' field. It supports only Hex, String, IP, FQDN. config option     edit 1         set code 125         set type hex         set value "000004035c69643a697070686f6e652e6d6974656c2e636f6d3b73775f746674703d3130392e3135392e     next end Solution 2: If the phone does not recognize the DHCP Option 125, try DHCP Option 43.  DHCP option 43 (type: string) would be: id:ipphone.test.com;sw_tftp=108.167.20.14;call_srv=108.167.20.14;l2p=6;dscp=46;