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
Mar 24 13:58:40.425290 osdx cfgd[1472]: [330528]Completed change to active configuration Mar 24 13:58:40.426447 osdx dhcpd[358752]: Wrote 0 leases to leases file. Mar 24 13:58:40.437729 osdx OSDxCLI[330528]: User 'admin' committed the configuration. Mar 24 13:58:40.460559 osdx OSDxCLI[330528]: User 'admin' left the configuration menu. Mar 24 13:58:40.483849 osdx dhcpd[358752]: Server starting service. Mar 24 13:58:40.596651 osdx OSDxCLI[330528]: User 'admin' executed a new command: 'system journal show | tail'. Mar 24 13:58:41.290464 osdx dhcpd[358752]: DHCPDISCOVER from 10:00:00:00:00:02 via eth0 Mar 24 13:58:42.291502 osdx dhcpd[358752]: DHCPOFFER on 10.0.0.5 to 10:00:00:00:00:02 via eth0 Mar 24 13:58:42.342442 osdx dhcpd[358752]: DHCPDISCOVER from 10:00:00:00:00:02 via eth0 Mar 24 13:58:42.342467 osdx dhcpd[358752]: 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
Mar 24 13:58:43.414561 osdx systemd-journald[1674]: Runtime Journal (/run/log/journal/aec016c8ce304ac68362b205c4156884) is 1.8M, max 13.8M, 11.9M free. Mar 24 13:58:43.415726 osdx systemd-journald[1674]: Received client request to rotate journal, rotating. Mar 24 13:58:43.415802 osdx systemd-journald[1674]: Vacuuming done, freed 0B of archived journals from /run/log/journal/aec016c8ce304ac68362b205c4156884. Mar 24 13:58:43.427109 osdx OSDxCLI[330528]: 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
Mar 24 13:58:43.414561 osdx systemd-journald[1674]: Runtime Journal (/run/log/journal/aec016c8ce304ac68362b205c4156884) is 1.8M, max 13.8M, 11.9M free. Mar 24 13:58:43.415726 osdx systemd-journald[1674]: Received client request to rotate journal, rotating. Mar 24 13:58:43.415802 osdx systemd-journald[1674]: Vacuuming done, freed 0B of archived journals from /run/log/journal/aec016c8ce304ac68362b205c4156884. Mar 24 13:58:43.427109 osdx OSDxCLI[330528]: User 'admin' executed a new command: 'system journal clear'. Mar 24 13:58:43.526753 osdx OSDxCLI[330528]: User 'admin' executed a new command: 'system journal show | tail'. Mar 24 13:58:43.640474 osdx OSDxCLI[330528]: User 'admin' executed a new command: 'system journal show | tail'. Mar 24 13:58:44.486267 osdx dhcpd[358808]: 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) Mar 24 13:58:45.534341 osdx dhcpd[358808]: 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 2026/03/24 13:58:47 2026/03/25 01:58:47 2026/03/24 13:58:47
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
Mar 24 13:58:54.641340 osdx cfgd[1472]: [330528]Completed change to active configuration Mar 24 13:58:54.643530 osdx dhcpd[359152]: Wrote 0 leases to leases file. Mar 24 13:58:54.654772 osdx OSDxCLI[330528]: User 'admin' committed the configuration. Mar 24 13:58:54.671937 osdx OSDxCLI[330528]: User 'admin' left the configuration menu. Mar 24 13:58:54.691175 osdx dhcpd[359152]: Server starting service. Mar 24 13:58:54.812888 osdx OSDxCLI[330528]: User 'admin' executed a new command: 'system journal show | tail'. Mar 24 13:58:55.117357 osdx dhcpd[359152]: DHCPDISCOVER from 10:00:00:00:00:02 via eth0 Mar 24 13:58:56.117826 osdx dhcpd[359152]: DHCPOFFER on 10.0.0.5 to 10:00:00:00:00:02 via eth0 Mar 24 13:58:56.166672 osdx dhcpd[359152]: DHCPDISCOVER from 10:00:00:00:00:02 via eth0 Mar 24 13:58:56.166722 osdx dhcpd[359152]: 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
Mar 24 13:58:57.495852 osdx systemd-journald[1674]: Runtime Journal (/run/log/journal/aec016c8ce304ac68362b205c4156884) is 1.8M, max 13.8M, 11.9M free. Mar 24 13:58:57.499050 osdx systemd-journald[1674]: Received client request to rotate journal, rotating. Mar 24 13:58:57.499107 osdx systemd-journald[1674]: Vacuuming done, freed 0B of archived journals from /run/log/journal/aec016c8ce304ac68362b205c4156884. Mar 24 13:58:57.505321 osdx OSDxCLI[330528]: 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
Mar 24 13:58:57.495852 osdx systemd-journald[1674]: Runtime Journal (/run/log/journal/aec016c8ce304ac68362b205c4156884) is 1.8M, max 13.8M, 11.9M free. Mar 24 13:58:57.499050 osdx systemd-journald[1674]: Received client request to rotate journal, rotating. Mar 24 13:58:57.499107 osdx systemd-journald[1674]: Vacuuming done, freed 0B of archived journals from /run/log/journal/aec016c8ce304ac68362b205c4156884. Mar 24 13:58:57.505321 osdx OSDxCLI[330528]: User 'admin' executed a new command: 'system journal clear'. Mar 24 13:58:57.728107 osdx OSDxCLI[330528]: User 'admin' executed a new command: 'system journal show | tail'. Mar 24 13:58:57.797045 osdx OSDxCLI[330528]: User 'admin' executed a new command: 'system journal show | tail'. Mar 24 13:58:58.281350 osdx dhcpd[359208]: 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) Mar 24 13:58:59.329174 osdx dhcpd[359208]: 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 2026/03/24 13:59:02 2026/03/25 01:59:02 2026/03/24 13:59:02