Check-Mac-Address

These scenarios show how the check-mac-address feature works for the DHCP server

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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 eth0
Show output
Mar 21 16:32:36.657825 osdx cfgd[1672]: [2248]Completed change to active configuration
Mar 21 16:32:36.682225 osdx OSDxCLI[2248]: User 'admin' committed the configuration.
Mar 21 16:32:36.730795 osdx OSDxCLI[2248]: User 'admin' left the configuration menu.
Mar 21 16:32:36.754306 osdx dhcpd[171601]: Wrote 0 leases to leases file.
Mar 21 16:32:36.837606 osdx dhcpd[171601]: Server starting service.
Mar 21 16:32:36.943191 osdx OSDxCLI[2248]: User 'admin' executed a new command: 'system journal show | tail'.
Mar 21 16:32:37.069566 osdx dhcpd[171601]: DHCPDISCOVER from 10:00:00:00:00:02 via eth0
Mar 21 16:32:38.070241 osdx dhcpd[171601]: DHCPOFFER on 10.0.0.5 to 10:00:00:00:00:02 via eth0
Mar 21 16:32:38.125864 osdx dhcpd[171601]: DHCPDISCOVER from 10:00:00:00:00:02 via eth0
Mar 21 16:32:38.125898 osdx dhcpd[171601]: 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 eth0
Show output
Mar 21 16:32:40.401353 osdx systemd-journald[1986]: Runtime Journal (/run/log/journal/5b174a9dbeeb42728284be3b4e954aec) is 2.1M, max 15.3M, 13.2M free.
Mar 21 16:32:40.405207 osdx systemd-journald[1986]: Received client request to rotate journal, rotating.
Mar 21 16:32:40.405286 osdx systemd-journald[1986]: Vacuuming done, freed 0B of archived journals from /run/log/journal/5b174a9dbeeb42728284be3b4e954aec.
Mar 21 16:32:40.419360 osdx OSDxCLI[2248]: User 'admin' executed a new command: 'system journal clear'.
Mar 21 16:32:40.569452 osdx dhcpd[171661]: Server starting service.

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 21 16:32:40.401353 osdx systemd-journald[1986]: Runtime Journal (/run/log/journal/5b174a9dbeeb42728284be3b4e954aec) is 2.1M, max 15.3M, 13.2M free.
Mar 21 16:32:40.405207 osdx systemd-journald[1986]: Received client request to rotate journal, rotating.
Mar 21 16:32:40.405286 osdx systemd-journald[1986]: Vacuuming done, freed 0B of archived journals from /run/log/journal/5b174a9dbeeb42728284be3b4e954aec.
Mar 21 16:32:40.419360 osdx OSDxCLI[2248]: User 'admin' executed a new command: 'system journal clear'.
Mar 21 16:32:40.569452 osdx dhcpd[171661]: Server starting service.
Mar 21 16:32:40.596048 osdx OSDxCLI[2248]: User 'admin' executed a new command: 'system journal show | tail'.
Mar 21 16:32:40.801361 osdx OSDxCLI[2248]: User 'admin' executed a new command: 'system journal show | tail'.
Mar 21 16:32:41.277458 osdx dhcpd[171661]: 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 21 16:32:42.329631 osdx dhcpd[171661]: 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:

10.0.0.5
Show 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:

10:00:00:00:00:05
Show output
10.0.0.5   10:00:00:00:00:05  2025/03/21 16:32:46  2025/03/22 04:32:46  2025/03/21 16:32:46

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 eth0
Show output
Mar 21 16:33:01.712965 osdx dhcpd[172032]: Wrote 0 leases to leases file.
Mar 21 16:33:01.716055 osdx cfgd[1672]: [2248]Completed change to active configuration
Mar 21 16:33:01.748081 osdx OSDxCLI[2248]: User 'admin' committed the configuration.
Mar 21 16:33:01.798982 osdx OSDxCLI[2248]: User 'admin' left the configuration menu.
Mar 21 16:33:01.809975 osdx dhcpd[172032]: Server starting service.
Mar 21 16:33:02.048356 osdx OSDxCLI[2248]: User 'admin' executed a new command: 'system journal show | tail'.
Mar 21 16:33:02.440844 osdx dhcpd[172032]: DHCPDISCOVER from 10:00:00:00:00:02 via eth0
Mar 21 16:33:03.441512 osdx dhcpd[172032]: DHCPOFFER on 10.0.0.5 to 10:00:00:00:00:02 via eth0
Mar 21 16:33:03.496848 osdx dhcpd[172032]: DHCPDISCOVER from 10:00:00:00:00:02 via eth0
Mar 21 16:33:03.496878 osdx dhcpd[172032]: 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 eth0
Show output
Mar 21 16:33:05.592941 osdx systemd-journald[1986]: Runtime Journal (/run/log/journal/5b174a9dbeeb42728284be3b4e954aec) is 2.0M, max 15.3M, 13.3M free.
Mar 21 16:33:05.605026 osdx systemd-journald[1986]: Received client request to rotate journal, rotating.
Mar 21 16:33:05.605133 osdx systemd-journald[1986]: Vacuuming done, freed 0B of archived journals from /run/log/journal/5b174a9dbeeb42728284be3b4e954aec.
Mar 21 16:33:05.605008 osdx dhcpd[172095]: 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 21 16:33:05.614619 osdx OSDxCLI[2248]: 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 21 16:33:05.592941 osdx systemd-journald[1986]: Runtime Journal (/run/log/journal/5b174a9dbeeb42728284be3b4e954aec) is 2.0M, max 15.3M, 13.3M free.
Mar 21 16:33:05.605026 osdx systemd-journald[1986]: Received client request to rotate journal, rotating.
Mar 21 16:33:05.605133 osdx systemd-journald[1986]: Vacuuming done, freed 0B of archived journals from /run/log/journal/5b174a9dbeeb42728284be3b4e954aec.
Mar 21 16:33:05.605008 osdx dhcpd[172095]: 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 21 16:33:05.614619 osdx OSDxCLI[2248]: User 'admin' executed a new command: 'system journal clear'.
Mar 21 16:33:05.819828 osdx OSDxCLI[2248]: User 'admin' executed a new command: 'system journal show | tail'.

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:

10.0.0.5
Show 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:

10:00:00:00:00:05
Show output
10.0.0.5   10:00:00:00:00:05  2025/03/21 16:33:09  2025/03/22 04:33:09  2025/03/21 16:33:09