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
Oct 20 17:52:01.347099 osdx cfgd[1655]: [399276]Completed change to active configuration Oct 20 17:52:01.348070 osdx dhcpd[623089]: Wrote 0 leases to leases file. Oct 20 17:52:01.358381 osdx OSDxCLI[399276]: User 'admin' committed the configuration. Oct 20 17:52:01.377100 osdx OSDxCLI[399276]: User 'admin' left the configuration menu. Oct 20 17:52:01.425428 osdx dhcpd[623089]: Server starting service. Oct 20 17:52:01.516560 osdx OSDxCLI[399276]: User 'admin' executed a new command: 'system journal show | tail'. Oct 20 17:52:02.449648 osdx dhcpd[623089]: DHCPDISCOVER from 10:00:00:00:00:02 via eth0 Oct 20 17:52:03.449852 osdx dhcpd[623089]: DHCPOFFER on 10.0.0.5 to 10:00:00:00:00:02 via eth0 Oct 20 17:52:03.497470 osdx dhcpd[623089]: DHCPDISCOVER from 10:00:00:00:00:02 via eth0 Oct 20 17:52:03.497493 osdx dhcpd[623089]: 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
Oct 20 17:52:04.257552 osdx systemd-journald[222010]: Runtime Journal (/run/log/journal/82a9756ca47e4d589aa55e1b1a6b94de) is 1.8M, max 13.8M, 11.9M free. Oct 20 17:52:04.261206 osdx systemd-journald[222010]: Received client request to rotate journal, rotating. Oct 20 17:52:04.261266 osdx systemd-journald[222010]: Vacuuming done, freed 0B of archived journals from /run/log/journal/82a9756ca47e4d589aa55e1b1a6b94de. Oct 20 17:52:04.269079 osdx OSDxCLI[399276]: 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
Oct 20 17:52:04.257552 osdx systemd-journald[222010]: Runtime Journal (/run/log/journal/82a9756ca47e4d589aa55e1b1a6b94de) is 1.8M, max 13.8M, 11.9M free. Oct 20 17:52:04.261206 osdx systemd-journald[222010]: Received client request to rotate journal, rotating. Oct 20 17:52:04.261266 osdx systemd-journald[222010]: Vacuuming done, freed 0B of archived journals from /run/log/journal/82a9756ca47e4d589aa55e1b1a6b94de. Oct 20 17:52:04.269079 osdx OSDxCLI[399276]: User 'admin' executed a new command: 'system journal clear'. Oct 20 17:52:04.336693 osdx OSDxCLI[399276]: User 'admin' executed a new command: 'system journal show | tail'. Oct 20 17:52:04.445011 osdx OSDxCLI[399276]: User 'admin' executed a new command: 'system journal show | tail'. Oct 20 17:52:04.537388 osdx dhcpd[623145]: 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) Oct 20 17:52:05.577307 osdx dhcpd[623145]: 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 2025/10/20 17:52:08 2025/10/21 05:52:08 2025/10/20 17:52:08
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
Oct 20 17:52:15.699447 osdx cfgd[1655]: [399276]Completed change to active configuration Oct 20 17:52:15.700038 osdx dhcpd[623491]: Wrote 0 leases to leases file. Oct 20 17:52:15.712238 osdx OSDxCLI[399276]: User 'admin' committed the configuration. Oct 20 17:52:15.734872 osdx OSDxCLI[399276]: User 'admin' left the configuration menu. Oct 20 17:52:15.749606 osdx dhcpd[623491]: Server starting service. Oct 20 17:52:15.894855 osdx OSDxCLI[399276]: User 'admin' executed a new command: 'system journal show | tail'. Oct 20 17:52:16.261321 osdx dhcpd[623491]: DHCPDISCOVER from 10:00:00:00:00:02 via eth0 Oct 20 17:52:17.262178 osdx dhcpd[623491]: DHCPOFFER on 10.0.0.5 to 10:00:00:00:00:02 via eth0 Oct 20 17:52:17.325000 osdx dhcpd[623491]: DHCPDISCOVER from 10:00:00:00:00:02 via eth0 Oct 20 17:52:17.325022 osdx dhcpd[623491]: 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
Oct 20 17:52:18.838906 osdx systemd-journald[222010]: Runtime Journal (/run/log/journal/82a9756ca47e4d589aa55e1b1a6b94de) is 1.8M, max 13.8M, 11.9M free. Oct 20 17:52:18.841544 osdx systemd-journald[222010]: Received client request to rotate journal, rotating. Oct 20 17:52:18.841596 osdx systemd-journald[222010]: Vacuuming done, freed 0B of archived journals from /run/log/journal/82a9756ca47e4d589aa55e1b1a6b94de. Oct 20 17:52:18.850472 osdx OSDxCLI[399276]: 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
Oct 20 17:52:18.838906 osdx systemd-journald[222010]: Runtime Journal (/run/log/journal/82a9756ca47e4d589aa55e1b1a6b94de) is 1.8M, max 13.8M, 11.9M free. Oct 20 17:52:18.841544 osdx systemd-journald[222010]: Received client request to rotate journal, rotating. Oct 20 17:52:18.841596 osdx systemd-journald[222010]: Vacuuming done, freed 0B of archived journals from /run/log/journal/82a9756ca47e4d589aa55e1b1a6b94de. Oct 20 17:52:18.850472 osdx OSDxCLI[399276]: User 'admin' executed a new command: 'system journal clear'. Oct 20 17:52:18.928254 osdx OSDxCLI[399276]: User 'admin' executed a new command: 'system journal show | tail'. Oct 20 17:52:19.010649 osdx OSDxCLI[399276]: User 'admin' executed a new command: 'system journal show | tail'. Oct 20 17:52:19.429128 osdx dhcpd[623547]: 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) Oct 20 17:52:20.476933 osdx dhcpd[623547]: 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 2025/10/20 17:52:23 2025/10/21 05:52:23 2025/10/20 17:52:23