Check-Mac-Address

These scenarios show how the feature check-mac-address works for 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 and see if there are warnings in your logs. Also, this test check the server’s behaviour in regular 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

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
Jun 20 18:07:33.350876 osdx OSDxCLI[23693]: User 'admin' added a new cfg line: 'set service dhcp-server shared-network dhcp subnet 10.0.0.0/24 start 10.0.0.5 stop 10.0.0.5'.
Jun 20 18:07:33.508223 osdx kernel: 8021q: adding VLAN 0 to HW filter on device eth0
Jun 20 18:07:33.572355 osdx systemd[1]: Started "DHCP Server Service instance main".
Jun 20 18:07:33.574541 osdx cfgd[1341]: [23693]Completed change to active configuration
Jun 20 18:07:33.577919 osdx OSDxCLI[23693]: User 'admin' committed the configuration.
Jun 20 18:07:33.581664 osdx dhcpd[30005]: Wrote 0 leases to leases file.
Jun 20 18:07:33.617417 osdx OSDxCLI[23693]: User 'admin' left the configuration menu.
Jun 20 18:07:33.648456 osdx dhcpd[30005]: Server starting service.
Jun 20 18:07:33.800699 osdx OSDxCLI[23693]: User 'admin' executed a new command: 'system journal show | tail'.
Jun 20 18:07:34.356762 osdx dhcpd[30005]: DHCPDISCOVER from 10:00:00:00:00:02 via eth0

Step 3: Set the following configuration 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
-- Logs begin at Thu 2024-06-20 18:07:35 UTC, end at Thu 2024-06-20 18:07:35 UTC. --
Jun 20 18:07:35.642200 osdx systemd-journald[1713]: Runtime journal (/run/log/journal/4bdaa9d5a32b43918ba3b0d5647305f4) is 2.0M, max 16.0M, 14.0M free.
Jun 20 18:07:35.659602 osdx OSDxCLI[23693]: 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
-- Logs begin at Thu 2024-06-20 18:07:35 UTC, end at Thu 2024-06-20 18:07:36 UTC. --
Jun 20 18:07:35.642200 osdx systemd-journald[1713]: Runtime journal (/run/log/journal/4bdaa9d5a32b43918ba3b0d5647305f4) is 2.0M, max 16.0M, 14.0M free.
Jun 20 18:07:35.659602 osdx OSDxCLI[23693]: User 'admin' executed a new command: 'system journal clear'.
Jun 20 18:07:35.787754 osdx OSDxCLI[23693]: User 'admin' executed a new command: 'system journal show | tail'.
Jun 20 18:07:35.887978 osdx OSDxCLI[23693]: User 'admin' executed a new command: 'system journal show | tail'.
Jun 20 18:07:36.448298 osdx dhcpd[30047]: 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 eth0 mac 10:00:00:00:00:05

Step 8: Set the following configuration in DUT1:

set interfaces 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  2024/06/20 18:07:39  2024/06/21 06:07:39  2024/06/20 18:07:39

Test Check MAC Address VRF

Description

This scenario configures a DHCP server with VRF instead of regular interfaces and checks the option check-mac-address. To check this option you will need to send packets with differences in Source MAC for link layer and the client MAC from the application layer.

Scenario

Step 1: Set the following configuration in DUT0:

set interfaces eth0 address 10.0.0.1/24
set interfaces 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 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
Jun 20 18:07:47.730716 osdx kernel: 8021q: adding VLAN 0 to HW filter on device eth0
Jun 20 18:07:47.791378 osdx systemd[1]: Started "DHCP Server Service instance VRF0".
Jun 20 18:07:47.794606 osdx cfgd[1341]: [23693]Completed change to active configuration
Jun 20 18:07:47.798385 osdx OSDxCLI[23693]: User 'admin' committed the configuration.
Jun 20 18:07:47.802469 osdx dhcpd[30333]: Wrote 0 leases to leases file.
Jun 20 18:07:47.842911 osdx OSDxCLI[23693]: User 'admin' left the configuration menu.
Jun 20 18:07:47.871031 osdx dhcpd[30333]: Server starting service.
Jun 20 18:07:48.003548 osdx OSDxCLI[23693]: User 'admin' executed a new command: 'system journal show | tail'.
Jun 20 18:07:48.102666 osdx dhcpd[30333]: DHCPDISCOVER from 10:00:00:00:00:02 via eth0
Jun 20 18:07:49.103775 osdx dhcpd[30333]: DHCPOFFER on 10.0.0.5 to 10:00:00:00:00:02 via eth0

Step 3: Set the following configuration 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
-- Logs begin at Thu 2024-06-20 18:07:49 UTC, end at Thu 2024-06-20 18:07:49 UTC. --
Jun 20 18:07:49.882798 osdx systemd-journald[1713]: Runtime journal (/run/log/journal/4bdaa9d5a32b43918ba3b0d5647305f4) is 2.0M, max 16.0M, 14.0M free.
Jun 20 18:07:49.903936 osdx OSDxCLI[23693]: User 'admin' executed a new command: 'system journal clear'.
Jun 20 18:07:49.950907 osdx dhcpd[30375]: 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
-- Logs begin at Thu 2024-06-20 18:07:49 UTC, end at Thu 2024-06-20 18:07:51 UTC. --
Jun 20 18:07:49.882798 osdx systemd-journald[1713]: Runtime journal (/run/log/journal/4bdaa9d5a32b43918ba3b0d5647305f4) is 2.0M, max 16.0M, 14.0M free.
Jun 20 18:07:49.903936 osdx OSDxCLI[23693]: User 'admin' executed a new command: 'system journal clear'.
Jun 20 18:07:49.950907 osdx dhcpd[30375]: Server starting service.
Jun 20 18:07:50.008899 osdx OSDxCLI[23693]: User 'admin' executed a new command: 'system journal show | tail'.
Jun 20 18:07:50.138891 osdx OSDxCLI[23693]: User 'admin' executed a new command: 'system journal show | tail'.
Jun 20 18:07:50.194713 osdx dhcpd[30375]: 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)
Jun 20 18:07:51.246800 osdx dhcpd[30375]: 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 eth0 mac 10:00:00:00:00:05

Step 8: Set the following configuration in DUT1:

set interfaces 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  2024/06/20 18:07:53  2024/06/21 06:07:53  2024/06/20 18:07:53