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
Feb 19 17:40:45.213863 osdx OSDxCLI[297559]: User 'admin' added a new cfg line: 'show working'. Feb 19 17:40:45.375484 osdx INFO[301472]: FRR daemons did not change Feb 19 17:40:45.424834 osdx kernel: 8021q: adding VLAN 0 to HW filter on device eth0 Feb 19 17:40:45.675115 osdx systemd[1]: Started dhcpd@main.service - "DHCP Server Service instance main". Feb 19 17:40:45.687655 osdx cfgd[1448]: [297559]Completed change to active configuration Feb 19 17:40:45.697880 osdx dhcpd[301541]: Wrote 0 leases to leases file. Feb 19 17:40:45.750995 osdx OSDxCLI[297559]: User 'admin' committed the configuration. Feb 19 17:40:45.774975 osdx dhcpd[301541]: Server starting service. Feb 19 17:40:45.808803 osdx OSDxCLI[297559]: User 'admin' left the configuration menu. Feb 19 17:40:46.032757 osdx dhcpd[301541]: 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 eth0Show output
Feb 19 17:40:47.451214 osdx systemd-journald[1749]: Runtime Journal (/run/log/journal/88d6d46990514354af95198d86011406) is 2.0M, max 15.3M, 13.3M free. Feb 19 17:40:47.454680 osdx systemd-journald[1749]: Received client request to rotate journal, rotating. Feb 19 17:40:47.454769 osdx systemd-journald[1749]: Vacuuming done, freed 0B of archived journals from /run/log/journal/88d6d46990514354af95198d86011406. Feb 19 17:40:47.468514 osdx OSDxCLI[297559]: 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
Feb 19 17:40:47.451214 osdx systemd-journald[1749]: Runtime Journal (/run/log/journal/88d6d46990514354af95198d86011406) is 2.0M, max 15.3M, 13.3M free. Feb 19 17:40:47.454680 osdx systemd-journald[1749]: Received client request to rotate journal, rotating. Feb 19 17:40:47.454769 osdx systemd-journald[1749]: Vacuuming done, freed 0B of archived journals from /run/log/journal/88d6d46990514354af95198d86011406. Feb 19 17:40:47.468514 osdx OSDxCLI[297559]: User 'admin' executed a new command: 'system journal clear'. Feb 19 17:40:47.578951 osdx OSDxCLI[297559]: User 'admin' executed a new command: 'system journal show | tail'. Feb 19 17:40:47.695940 osdx OSDxCLI[297559]: User 'admin' executed a new command: 'system journal show | tail'. Feb 19 17:40:48.130757 osdx dhcpd[301586]: 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:
10:00:00:00:00:05Show output
10.0.0.5 10:00:00:00:00:05 2025/02/19 17:40:51 2025/02/20 05:40:51 2025/02/19 17:40:51
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
Feb 19 17:41:01.870325 osdx (udev-worker)[301785]: Network interface NamePolicy= disabled on kernel command line. Feb 19 17:41:01.902677 osdx kernel: 8021q: adding VLAN 0 to HW filter on device eth0 Feb 19 17:41:02.022680 osdx kernel: 8021q: adding VLAN 0 to HW filter on device eth0 Feb 19 17:41:02.159139 osdx systemd[1]: Started dhcpd@VRF0.service - "DHCP Server Service instance VRF0". Feb 19 17:41:02.161626 osdx cfgd[1448]: [297559]Completed change to active configuration Feb 19 17:41:02.163534 osdx dhcpd[301893]: Wrote 0 leases to leases file. Feb 19 17:41:02.202632 osdx OSDxCLI[297559]: User 'admin' committed the configuration. Feb 19 17:41:02.222829 osdx dhcpd[301893]: Server starting service. Feb 19 17:41:02.252336 osdx OSDxCLI[297559]: User 'admin' left the configuration menu. Feb 19 17:41:02.254869 osdx dhcpd[301893]: 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 eth0Show output
Feb 19 17:41:03.289717 osdx systemd-journald[1749]: Runtime Journal (/run/log/journal/88d6d46990514354af95198d86011406) is 2.0M, max 15.3M, 13.3M free. Feb 19 17:41:03.290670 osdx systemd-journald[1749]: Received client request to rotate journal, rotating. Feb 19 17:41:03.290741 osdx systemd-journald[1749]: Vacuuming done, freed 0B of archived journals from /run/log/journal/88d6d46990514354af95198d86011406. Feb 19 17:41:03.303742 osdx dhcpd[301941]: 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) Feb 19 17:41:03.304971 osdx OSDxCLI[297559]: 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
Feb 19 17:41:03.289717 osdx systemd-journald[1749]: Runtime Journal (/run/log/journal/88d6d46990514354af95198d86011406) is 2.0M, max 15.3M, 13.3M free. Feb 19 17:41:03.290670 osdx systemd-journald[1749]: Received client request to rotate journal, rotating. Feb 19 17:41:03.290741 osdx systemd-journald[1749]: Vacuuming done, freed 0B of archived journals from /run/log/journal/88d6d46990514354af95198d86011406. Feb 19 17:41:03.303742 osdx dhcpd[301941]: 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) Feb 19 17:41:03.304971 osdx OSDxCLI[297559]: User 'admin' executed a new command: 'system journal clear'. Feb 19 17:41:03.399867 osdx OSDxCLI[297559]: 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:
10:00:00:00:00:05Show output
10.0.0.5 10:00:00:00:00:05 2025/02/19 17:41:06 2025/02/20 05:41:06 2025/02/19 17:41:06