Check-Mac-Address
These scenarios show how the
check-mac-address feature works for the DHCP server
Test Check MAC Address
Description
The check-mac-address option filters packets if there are differences between the MAC address found at the ethernet header and the MAC address found in the DHCP packet.
To check this option, you should send packets with these differences and enable this option to see if warnings appear in your logs.
Also, this test checks how the server behaves under normal conditions.
Scenario
Step 1: Set the following configuration in DUT0 :
set interfaces ethernet eth0 address 10.0.0.1/24 set service dhcp-server shared-network dhcp subnet 10.0.0.0/24 start 10.0.0.5 stop 10.0.0.5 set system login user admin authentication encrypted-password '$6$GSjsCj8gHLv$/VcqU6FLi6CT2Oxn0MJQ2C2tqnRDrYKNF8HIYWJp68nvXvPdFccDsT04.WtigUONbKYrgKg8d6rEs8PjljMkH0'
Step 2: Run the command system journal show | tail on DUT0 and check whether the output contains the following tokens:
DHCPDISCOVER from 10:00:00:00:00:02 via eth0Show output
Jun 03 16:26:08.827815 osdx dhcpd[734021]: Wrote 0 leases to leases file. Jun 03 16:26:08.860829 osdx dhcpd[734021]: Server starting service. Jun 03 16:26:09.011881 osdx cfgd[1899]: [699835]Completed change to active configuration Jun 03 16:26:09.012493 osdx OSDxCLI[699835]: User 'admin' committed the configuration. Jun 03 16:26:09.033725 osdx OSDxCLI[699835]: User 'admin' left the configuration menu. Jun 03 16:26:09.204892 osdx OSDxCLI[699835]: User 'admin' executed a new command: 'system journal show | tail'. Jun 03 16:26:09.839704 osdx dhcpd[734021]: DHCPDISCOVER from 10:00:00:00:00:02 via eth0 Jun 03 16:26:10.840608 osdx dhcpd[734021]: DHCPOFFER on 10.0.0.5 to 10:00:00:00:00:02 via eth0 Jun 03 16:26:10.907657 osdx dhcpd[734021]: DHCPDISCOVER from 10:00:00:00:00:02 via eth0 Jun 03 16:26:10.907690 osdx dhcpd[734021]: DHCPOFFER on 10.0.0.5 to 10:00:00:00:00:02 via eth0
Step 3: Modify the following configuration lines in DUT0 :
set service dhcp-server check-mac-address
Step 4: Run the command system journal clear on DUT0.
Step 5: Run the command system journal show | tail on DUT0 and check whether the output does not contain the following tokens:
DHCPDISCOVER from 10:00:00:00:00:02 via eth0Show output
Jun 03 16:26:12.136191 osdx systemd-journald[262779]: Runtime Journal (/run/log/journal/140771393e044d28bd27951346e92000) is 1.8M, max 13.8M, 11.9M free. Jun 03 16:26:12.137046 osdx systemd-journald[262779]: Received client request to rotate journal, rotating. Jun 03 16:26:12.137088 osdx systemd-journald[262779]: Vacuuming done, freed 0B of archived journals from /run/log/journal/140771393e044d28bd27951346e92000. Jun 03 16:26:12.153227 osdx OSDxCLI[699835]: User 'admin' executed a new command: 'system journal clear'.
Step 6: Run the command system journal show | tail on DUT0 and check whether the output contains the following tokens:
MAC received in DHCP packet (10:00:00:00:00:02) is different than source MAC in ethernet header (10:00:00:00:00:01)Show output
Jun 03 16:26:12.136191 osdx systemd-journald[262779]: Runtime Journal (/run/log/journal/140771393e044d28bd27951346e92000) is 1.8M, max 13.8M, 11.9M free. Jun 03 16:26:12.137046 osdx systemd-journald[262779]: Received client request to rotate journal, rotating. Jun 03 16:26:12.137088 osdx systemd-journald[262779]: Vacuuming done, freed 0B of archived journals from /run/log/journal/140771393e044d28bd27951346e92000. Jun 03 16:26:12.153227 osdx OSDxCLI[699835]: User 'admin' executed a new command: 'system journal clear'. Jun 03 16:26:12.259010 osdx OSDxCLI[699835]: User 'admin' executed a new command: 'system journal show | tail'. Jun 03 16:26:12.372421 osdx OSDxCLI[699835]: User 'admin' executed a new command: 'system journal show | tail'. Jun 03 16:26:13.089588 osdx dhcpd[734093]: MAC received in DHCP packet (10:00:00:00:00:02) is different than source MAC in ethernet header (10:00:00:00:00:01) Jun 03 16:26:14.143383 osdx dhcpd[734093]: MAC received in DHCP packet (10:00:00:00:00:02) is different than source MAC in ethernet header (10:00:00:00:00:01)
Step 7: Set the following configuration in DUT1 :
set interfaces ethernet eth0 mac '10:00:00:00:00:05' set system login user admin authentication encrypted-password '$6$GSjsCj8gHLv$/VcqU6FLi6CT2Oxn0MJQ2C2tqnRDrYKNF8HIYWJp68nvXvPdFccDsT04.WtigUONbKYrgKg8d6rEs8PjljMkH0'
Step 8: Modify the following configuration lines in DUT1 :
set interfaces ethernet eth0 address dhcp
Step 9: Run the command interfaces ethernet eth0 show on DUT1 and check whether the output contains the following tokens:
10.0.0.5Show output
----------------------------------------------------------------- Name IP Address Admin Oper Vrf Description ----------------------------------------------------------------- eth0 10.0.0.5/24 up up fe80::dcad:beff:feef:6c10/64
Step 10: Run the command service dhcp-server show leases main | grep 10.0.0.5 on DUT0 and check whether the output contains the following tokens:
10:00:00:00:00:05Show output
10.0.0.5 10:00:00:00:00:05 2026/06/03 16:26:16 2026/06/04 04:26:16 2026/06/03 16:26:16
Test Check MAC Address VRF
Description
This scenario configures a DHCP server with VRF instead of regular interfaces and checks the check-mac-address option.
To check this option, you will need to send packets with differences in the Source MAC for the link layer and the client MAC from the application layer.
Scenario
Step 1: Set the following configuration in DUT0 :
set interfaces ethernet eth0 address 10.0.0.1/24 set interfaces ethernet eth0 vrf VRF0 set service dhcp-server shared-network dhcp local-vrf VRF0 set service dhcp-server shared-network dhcp subnet 10.0.0.0/24 start 10.0.0.5 stop 10.0.0.6 set system login user admin authentication encrypted-password '$6$GSjsCj8gHLv$/VcqU6FLi6CT2Oxn0MJQ2C2tqnRDrYKNF8HIYWJp68nvXvPdFccDsT04.WtigUONbKYrgKg8d6rEs8PjljMkH0' set system vrf VRF0
Step 2: Run the command system journal show | tail on DUT0 and check whether the output contains the following tokens:
DHCPDISCOVER from 10:00:00:00:00:02 via eth0Show output
Jun 03 16:26:24.892750 osdx dhcpd[734500]: Wrote 0 leases to leases file. Jun 03 16:26:24.929325 osdx dhcpd[734500]: Server starting service. Jun 03 16:26:25.064778 osdx cfgd[1899]: [699835]Completed change to active configuration Jun 03 16:26:25.065342 osdx OSDxCLI[699835]: User 'admin' committed the configuration. Jun 03 16:26:25.080750 osdx OSDxCLI[699835]: User 'admin' left the configuration menu. Jun 03 16:26:25.239768 osdx OSDxCLI[699835]: User 'admin' executed a new command: 'system journal show | tail'. Jun 03 16:26:25.676093 osdx dhcpd[734500]: DHCPDISCOVER from 10:00:00:00:00:02 via eth0 Jun 03 16:26:26.676464 osdx dhcpd[734500]: DHCPOFFER on 10.0.0.5 to 10:00:00:00:00:02 via eth0 Jun 03 16:26:26.731994 osdx dhcpd[734500]: DHCPDISCOVER from 10:00:00:00:00:02 via eth0 Jun 03 16:26:26.732022 osdx dhcpd[734500]: DHCPOFFER on 10.0.0.5 to 10:00:00:00:00:02 via eth0
Step 3: Modify the following configuration lines in DUT0 :
set service dhcp-server check-mac-address
Step 4: Run the command system journal clear on DUT0.
Step 5: Run the command system journal show | tail on DUT0 and check whether the output does not contain the following tokens:
DHCPDISCOVER from 10:00:00:00:00:02 via eth0Show output
Jun 03 16:26:27.944530 osdx systemd-journald[262779]: Runtime Journal (/run/log/journal/140771393e044d28bd27951346e92000) is 2.4M, max 13.8M, 11.4M free. Jun 03 16:26:27.945186 osdx systemd-journald[262779]: Received client request to rotate journal, rotating. Jun 03 16:26:27.945254 osdx systemd-journald[262779]: Vacuuming done, freed 0B of archived journals from /run/log/journal/140771393e044d28bd27951346e92000. Jun 03 16:26:27.957456 osdx OSDxCLI[699835]: User 'admin' executed a new command: 'system journal clear'.
Step 6: Run the command system journal show | tail on DUT0 and check whether the output contains the following tokens:
MAC received in DHCP packet (10:00:00:00:00:02) is different than source MAC in ethernet header (10:00:00:00:00:01)Show output
Jun 03 16:26:27.944530 osdx systemd-journald[262779]: Runtime Journal (/run/log/journal/140771393e044d28bd27951346e92000) is 2.4M, max 13.8M, 11.4M free. Jun 03 16:26:27.945186 osdx systemd-journald[262779]: Received client request to rotate journal, rotating. Jun 03 16:26:27.945254 osdx systemd-journald[262779]: Vacuuming done, freed 0B of archived journals from /run/log/journal/140771393e044d28bd27951346e92000. Jun 03 16:26:27.957456 osdx OSDxCLI[699835]: User 'admin' executed a new command: 'system journal clear'. Jun 03 16:26:28.024693 osdx OSDxCLI[699835]: User 'admin' executed a new command: 'system journal show | tail'. Jun 03 16:26:28.137027 osdx OSDxCLI[699835]: User 'admin' executed a new command: 'system journal show | tail'. Jun 03 16:26:28.863840 osdx dhcpd[734572]: MAC received in DHCP packet (10:00:00:00:00:02) is different than source MAC in ethernet header (10:00:00:00:00:01) Jun 03 16:26:29.923886 osdx dhcpd[734572]: MAC received in DHCP packet (10:00:00:00:00:02) is different than source MAC in ethernet header (10:00:00:00:00:01)
Step 7: Set the following configuration in DUT1 :
set interfaces ethernet eth0 mac '10:00:00:00:00:05' set system login user admin authentication encrypted-password '$6$GSjsCj8gHLv$/VcqU6FLi6CT2Oxn0MJQ2C2tqnRDrYKNF8HIYWJp68nvXvPdFccDsT04.WtigUONbKYrgKg8d6rEs8PjljMkH0'
Step 8: Modify the following configuration lines in DUT1 :
set interfaces ethernet eth0 address dhcp
Step 9: Run the command interfaces ethernet eth0 show on DUT1 and check whether the output contains the following tokens:
10.0.0.5Show output
----------------------------------------------------------------- Name IP Address Admin Oper Vrf Description ----------------------------------------------------------------- eth0 10.0.0.5/24 up up fe80::dcad:beff:feef:6c10/64
Step 10: Run the command service dhcp-server show leases VRF0 | grep 10.0.0.5 on DUT0 and check whether the output contains the following tokens:
10:00:00:00:00:05Show output
10.0.0.5 10:00:00:00:00:05 2026/06/03 16:26:32 2026/06/04 04:26:32 2026/06/03 16:26:32