I have a scenario like this topology
Customer End device --> Customer Switch --> My Cisco Router --> My network --> My Cisco Router --> Customer Switch --> Customer End device
The only part of the network where I can view the config is on
My Cisco Router && My network
The customer's end device needs to get a DHCP address assigned to them, and their DHCP server lives at a Data Center, across my network.
The customer states that they are sending DHCP requests but they are not being received.
I am making the 'assumption' that the switch is using a DHCP helper address, I say 'assumption', because nobody will tell me YES or NO.
The same customer has other working scenarios on my network.
So, I want to prove/disprove what is happening with the DHCP requests that are being sent from the customer end device.
I want to enable debugging on My Cisco Router, but what debugging do I enable?
- debug ip dhcp server packet - don't get any hits
- debug ip udp port 67 - don't get any hits
- debug ip udp port 68 - don't get any hits
So if the customer has IP helper, I think this will send a replicated unicast to My Cisco Router, I think this is TCP rather than UDP.
I don't think I can debug a particular port, because I think when My Cisco Router receives the packet, it will only look up the OSI model until Layer 3, and then realize this is not for me, and send it on its way.