I'm having an issue where a Cisco 7945G IP phone connected to a Juniper EX4200 will not pull an IP address from DHCP server. When I connect the phone to a Cisco 3750 switch it works fine everytime. I have LLDP and LLDP-MED turned on. Does this have something to do with CDP which is why Cisco to Cisco works fine? There is no VLAN set on the phone.
Does not work:
MX-->trunk-->EX--access--->7945
Works:
MX-->trunk--->EX--access--->3750--access--->7945
I have an analyzer config on the EX and I'm not seeing the DHCP DISCOVER packets on the trunk facing the MX. When the phone is connected to the Cisco switch I see the DHCP DISCOVER packets just fine. If I connect a Windows machine to the EX set for DHCP I also see the DHCP DISCOVER packets. So what is stopping the EX from forwarding the DHCP packets from a directly connect Cisco IP Phone?