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 command system journal show | tail at DUT0 and check if output contains the following tokens:
DHCPDISCOVER from 10:00:00:00:00:02 via eth0Show output
Feb 12 19:22:25.567087 osdx cfgd[1631]: [386377]Completed change to active configuration Feb 12 19:22:25.567590 osdx dhcpd[386705]: Wrote 0 leases to leases file. Feb 12 19:22:25.579070 osdx OSDxCLI[386377]: User 'admin' committed the configuration. Feb 12 19:22:25.595524 osdx OSDxCLI[386377]: User 'admin' left the configuration menu. Feb 12 19:22:25.621061 osdx dhcpd[386705]: Server starting service. Feb 12 19:22:25.767514 osdx OSDxCLI[386377]: User 'admin' executed a new command: 'system journal show | tail'. Feb 12 19:22:26.474971 osdx dhcpd[386705]: DHCPDISCOVER from 10:00:00:00:00:02 via eth0 Feb 12 19:22:27.475284 osdx dhcpd[386705]: DHCPOFFER on 10.0.0.5 to 10:00:00:00:00:02 via eth0 Feb 12 19:22:27.530765 osdx dhcpd[386705]: DHCPDISCOVER from 10:00:00:00:00:02 via eth0 Feb 12 19:22:27.530797 osdx dhcpd[386705]: 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 command system journal clear at DUT0.
Step 5: Run command system journal show | tail at DUT0 and check if output does not contain the following tokens:
DHCPDISCOVER from 10:00:00:00:00:02 via eth0Show output
Feb 12 19:22:28.442427 osdx systemd-journald[1959]: Runtime Journal (/run/log/journal/fef7273cfed74888920ec39438478308) is 2.3M, max 17.2M, 14.9M free. Feb 12 19:22:28.444929 osdx systemd-journald[1959]: Received client request to rotate journal, rotating. Feb 12 19:22:28.445008 osdx systemd-journald[1959]: Vacuuming done, freed 0B of archived journals from /run/log/journal/fef7273cfed74888920ec39438478308. Feb 12 19:22:28.458077 osdx OSDxCLI[386377]: User 'admin' executed a new command: 'system journal clear'.
Step 6: Run command system journal show | tail at DUT0 and check if 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
Feb 12 19:22:28.442427 osdx systemd-journald[1959]: Runtime Journal (/run/log/journal/fef7273cfed74888920ec39438478308) is 2.3M, max 17.2M, 14.9M free. Feb 12 19:22:28.444929 osdx systemd-journald[1959]: Received client request to rotate journal, rotating. Feb 12 19:22:28.445008 osdx systemd-journald[1959]: Vacuuming done, freed 0B of archived journals from /run/log/journal/fef7273cfed74888920ec39438478308. Feb 12 19:22:28.458077 osdx OSDxCLI[386377]: User 'admin' executed a new command: 'system journal clear'. Feb 12 19:22:28.564110 osdx OSDxCLI[386377]: User 'admin' executed a new command: 'system journal show | tail'. Feb 12 19:22:28.610950 osdx dhcpd[386763]: 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 command interfaces ethernet eth0 show at DUT1 and check if 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 command service dhcp-server show leases main | grep 10.0.0.5 at DUT0 and check if output contains the following tokens:
10:00:00:00:00:05Show output
10.0.0.5 10:00:00:00:00:05 2026/02/12 19:22:30 2026/02/13 07:22:30 2026/02/12 19:22:30
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 command system journal show | tail at DUT0 and check if output contains the following tokens:
DHCPDISCOVER from 10:00:00:00:00:02 via eth0Show output
Feb 12 19:22:38.913260 osdx cfgd[1631]: [386377]Completed change to active configuration Feb 12 19:22:38.913996 osdx dhcpd[387141]: Wrote 0 leases to leases file. Feb 12 19:22:38.927839 osdx OSDxCLI[386377]: User 'admin' committed the configuration. Feb 12 19:22:38.939288 osdx dhcpd[387141]: Server starting service. Feb 12 19:22:38.957611 osdx OSDxCLI[386377]: User 'admin' left the configuration menu. Feb 12 19:22:39.098054 osdx OSDxCLI[386377]: User 'admin' executed a new command: 'system journal show | tail'. Feb 12 19:22:39.500537 osdx dhcpd[387141]: DHCPDISCOVER from 10:00:00:00:00:02 via eth0 Feb 12 19:22:40.501522 osdx dhcpd[387141]: DHCPOFFER on 10.0.0.5 to 10:00:00:00:00:02 via eth0 Feb 12 19:22:40.556398 osdx dhcpd[387141]: DHCPDISCOVER from 10:00:00:00:00:02 via eth0 Feb 12 19:22:40.556430 osdx dhcpd[387141]: 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 command system journal clear at DUT0.
Step 5: Run command system journal show | tail at DUT0 and check if output does not contain the following tokens:
DHCPDISCOVER from 10:00:00:00:00:02 via eth0Show output
Feb 12 19:22:42.088852 osdx systemd-journald[1959]: Runtime Journal (/run/log/journal/fef7273cfed74888920ec39438478308) is 2.2M, max 17.2M, 14.9M free. Feb 12 19:22:42.091163 osdx systemd-journald[1959]: Received client request to rotate journal, rotating. Feb 12 19:22:42.091233 osdx systemd-journald[1959]: Vacuuming done, freed 0B of archived journals from /run/log/journal/fef7273cfed74888920ec39438478308. Feb 12 19:22:42.100911 osdx OSDxCLI[386377]: User 'admin' executed a new command: 'system journal clear'.
Step 6: Run command system journal show | tail at DUT0 and check if 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
Feb 12 19:22:42.088852 osdx systemd-journald[1959]: Runtime Journal (/run/log/journal/fef7273cfed74888920ec39438478308) is 2.2M, max 17.2M, 14.9M free. Feb 12 19:22:42.091163 osdx systemd-journald[1959]: Received client request to rotate journal, rotating. Feb 12 19:22:42.091233 osdx systemd-journald[1959]: Vacuuming done, freed 0B of archived journals from /run/log/journal/fef7273cfed74888920ec39438478308. Feb 12 19:22:42.100911 osdx OSDxCLI[386377]: User 'admin' executed a new command: 'system journal clear'. Feb 12 19:22:42.176400 osdx OSDxCLI[386377]: User 'admin' executed a new command: 'system journal show | tail'. Feb 12 19:22:42.256116 osdx OSDxCLI[386377]: User 'admin' executed a new command: 'system journal show | tail'. Feb 12 19:22:42.668364 osdx dhcpd[387197]: 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) Feb 12 19:22:43.716264 osdx dhcpd[387197]: 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 command interfaces ethernet eth0 show at DUT1 and check if 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 command service dhcp-server show leases VRF0 | grep 10.0.0.5 at DUT0 and check if output contains the following tokens:
10:00:00:00:00:05Show output
10.0.0.5 10:00:00:00:00:05 2026/02/12 19:22:46 2026/02/13 07:22:46 2026/02/12 19:22:46