Network Topology
VM--Leaf--Border(spine)-DHCP server
Problem Description
When the VM in the ADDC network set as dhvp mode, it cannot obtain a ip address from DHCP server in the same L2 network or cannot ip address from outside DHCP server via dhcp relay. and the dhcp server cannot receive the dhcp discover packet.
And the Network is ok, If you configure a ip address for th vm manually, you can ping the dhcp server.
Process Analysis
We enable dhcp to controller in the ADDC controller and it will deploy some openflow flow-table to the border and leaf.
Flow entry 4 information:
COOKIE: 0x2c324757415057, priority: 61000, hard time: 0, idle time: 0, flags:
flow_send_rem, byte count: 25415600, packet count: 76215
Create time:18:12:35 07/26/2023, Last modified time:18:12:35 07/26/2023
Match information:
Ethernet type: 0x0800
IP protocol: 17
UDP source port: 68, mask: 0xffff
UDP destination port: 67, mask: 0xffff
Experimenter:
FlowFlag: 0x6
Instruction information:
Write actions:
Output interface: Controller, send length: 65509 bytes
Solution
Disable the dhcp to contoller for this private network in ADDC controller.
And addc wil deploy another high priority flow-table:
Flow entry 11 information:
COOKIE: 0x2c324757415057, priority: 61500, hard time: 0, idle time: 0, flags:
flow_send_rem, byte count: 0, packet count: 0
Create time:18:12:35 07/26/2023, Last modified time:18:12:35 07/26/2023
Match information:
Ethernet type: 0x8035
Tunnel ID: 2001, mask: 0xffffffffffffffff
Instruction information:
Write actions:
Output interface: Normal # nomal forward