Check-Mac-Address

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

../../../_images/check-mac-address.svg

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
Jul 30 12:30:23.287252 osdx OSDxCLI[402249]: User 'admin' added a new cfg line: 'show working'.
Jul 30 12:30:23.405797 osdx kernel: 8021q: adding VLAN 0 to HW filter on device eth0
Jul 30 12:30:23.478107 osdx systemd[1]: Started dhcpd@main.service - "DHCP Server Service instance main".
Jul 30 12:30:23.479711 osdx cfgd[1242]: [402249]Completed change to active configuration
Jul 30 12:30:23.481479 osdx OSDxCLI[402249]: User 'admin' committed the configuration.
Jul 30 12:30:23.481869 osdx dhcpd[406695]: Wrote 0 leases to leases file.
Jul 30 12:30:23.513257 osdx OSDxCLI[402249]: User 'admin' left the configuration menu.
Jul 30 12:30:23.533985 osdx dhcpd[406695]: Server starting service.
Jul 30 12:30:23.634973 osdx OSDxCLI[402249]: User 'admin' executed a new command: 'system journal show | tail'.
Jul 30 12:30:24.275196 osdx dhcpd[406695]: DHCPDISCOVER from 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
Jul 30 12:30:25.269235 osdx systemd-journald[60253]: Runtime Journal (/run/log/journal/22c37bf8be29452e87aca50c6265032f) is 2.0M, max 15.3M, 13.3M free.
Jul 30 12:30:25.269802 osdx systemd-journald[60253]: Received client request to rotate journal, rotating.
Jul 30 12:30:25.269833 osdx systemd-journald[60253]: Vacuuming done, freed 0B of archived journals from /run/log/journal/22c37bf8be29452e87aca50c6265032f.
Jul 30 12:30:25.278247 osdx OSDxCLI[402249]: User 'admin' executed a new command: 'system journal clear'.
Jul 30 12:30:25.307001 osdx dhcpd[406738]: 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 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
Jul 30 12:30:25.269235 osdx systemd-journald[60253]: Runtime Journal (/run/log/journal/22c37bf8be29452e87aca50c6265032f) is 2.0M, max 15.3M, 13.3M free.
Jul 30 12:30:25.269802 osdx systemd-journald[60253]: Received client request to rotate journal, rotating.
Jul 30 12:30:25.269833 osdx systemd-journald[60253]: Vacuuming done, freed 0B of archived journals from /run/log/journal/22c37bf8be29452e87aca50c6265032f.
Jul 30 12:30:25.278247 osdx OSDxCLI[402249]: User 'admin' executed a new command: 'system journal clear'.
Jul 30 12:30:25.307001 osdx dhcpd[406738]: 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)
Jul 30 12:30:25.336191 osdx OSDxCLI[402249]: 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:6c20/64

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  2024/07/30 12:30:27  2024/07/31 00:30:27  2024/07/30 12:30:27

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
Jul 30 12:30:32.604458 osdx kernel: 8021q: adding VLAN 0 to HW filter on device eth0
Jul 30 12:30:32.636458 osdx kernel: 8021q: adding VLAN 0 to HW filter on device eth0
Jul 30 12:30:32.704824 osdx systemd[1]: Started dhcpd@VRF0.service - "DHCP Server Service instance VRF0".
Jul 30 12:30:32.706167 osdx cfgd[1242]: [402249]Completed change to active configuration
Jul 30 12:30:32.708119 osdx dhcpd[406996]: Wrote 0 leases to leases file.
Jul 30 12:30:32.708376 osdx OSDxCLI[402249]: User 'admin' committed the configuration.
Jul 30 12:30:32.731084 osdx OSDxCLI[402249]: User 'admin' left the configuration menu.
Jul 30 12:30:32.744592 osdx dhcpd[406996]: Server starting service.
Jul 30 12:30:32.859778 osdx OSDxCLI[402249]: User 'admin' executed a new command: 'system journal show | tail'.
Jul 30 12:30:33.189573 osdx dhcpd[406996]: DHCPDISCOVER from 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
Jul 30 12:30:34.496325 osdx systemd-journald[60253]: Runtime Journal (/run/log/journal/22c37bf8be29452e87aca50c6265032f) is 2.0M, max 15.3M, 13.3M free.
Jul 30 12:30:34.496774 osdx systemd-journald[60253]: Received client request to rotate journal, rotating.
Jul 30 12:30:34.496802 osdx systemd-journald[60253]: Vacuuming done, freed 0B of archived journals from /run/log/journal/22c37bf8be29452e87aca50c6265032f.
Jul 30 12:30:34.505510 osdx OSDxCLI[402249]: 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
Jul 30 12:30:34.496325 osdx systemd-journald[60253]: Runtime Journal (/run/log/journal/22c37bf8be29452e87aca50c6265032f) is 2.0M, max 15.3M, 13.3M free.
Jul 30 12:30:34.496774 osdx systemd-journald[60253]: Received client request to rotate journal, rotating.
Jul 30 12:30:34.496802 osdx systemd-journald[60253]: Vacuuming done, freed 0B of archived journals from /run/log/journal/22c37bf8be29452e87aca50c6265032f.
Jul 30 12:30:34.505510 osdx OSDxCLI[402249]: User 'admin' executed a new command: 'system journal clear'.
Jul 30 12:30:34.559421 osdx OSDxCLI[402249]: User 'admin' executed a new command: 'system journal show | tail'.
Jul 30 12:30:34.661668 osdx OSDxCLI[402249]: User 'admin' executed a new command: 'system journal show | tail'.
Jul 30 12:30:35.265342 osdx dhcpd[407039]: 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:6c20/64

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  2024/07/30 12:30:37  2024/07/31 00:30:37  2024/07/30 12:30:37