Relay

Contents

This scenario shows how to configure service dhcp-relay. The relay agent must be used when the DHCP server and the DHCP clients are not connected to the same layer 2 domain.

Test DHCP Relay

Description

This example demonstrates how to configure a DHCP relay instance in DUT0 to forward DHCP requests from DUT2 to DUT1.

Scenario

Step 1: Set the following configuration in DUT0 :

set interfaces ethernet eth0 vif 100 address 10.0.0.2/24
set interfaces ethernet eth1 vif 200 address 20.0.0.2/24
set service dhcp-relay INS downstream-interface eth1.200
set service dhcp-relay INS server 10.0.0.1
set service dhcp-relay INS upstream-interface eth0.100
set system login user admin authentication encrypted-password '$6$GSjsCj8gHLv$/VcqU6FLi6CT2Oxn0MJQ2C2tqnRDrYKNF8HIYWJp68nvXvPdFccDsT04.WtigUONbKYrgKg8d6rEs8PjljMkH0'

Step 2: Set the following configuration in DUT1 :

set interfaces ethernet eth0 vif 100 address 10.0.0.1/24
set protocols static route 0.0.0.0/0 next-hop 10.0.0.2
set service dhcp-server shared-network dummy subnet 10.0.0.1/32
set service dhcp-server shared-network remote subnet 20.0.0.0/24 start 20.0.0.50 stop 20.0.0.50
set system login user admin authentication encrypted-password '$6$GSjsCj8gHLv$/VcqU6FLi6CT2Oxn0MJQ2C2tqnRDrYKNF8HIYWJp68nvXvPdFccDsT04.WtigUONbKYrgKg8d6rEs8PjljMkH0'

Step 3: Set the following configuration in DUT2 :

set interfaces ethernet eth0 vif 200 address dhcp
set system login user admin authentication encrypted-password '$6$GSjsCj8gHLv$/VcqU6FLi6CT2Oxn0MJQ2C2tqnRDrYKNF8HIYWJp68nvXvPdFccDsT04.WtigUONbKYrgKg8d6rEs8PjljMkH0'

Step 4: Ping IP address 10.0.0.1 from DUT0:

admin@DUT0$ ping 10.0.0.1 count 1 size 56 timeout 1

Show output

PING 10.0.0.1 (10.0.0.1) 56(84) bytes of data.
64 bytes from 10.0.0.1: icmp_seq=1 ttl=64 time=0.403 ms

--- 10.0.0.1 ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 0.403/0.403/0.403/0.000 ms

Step 5: Run command interfaces ethernet show at DUT2 and check if output contains the following tokens:

20.0.0.50

Show output

---------------------------------------------------------------------
  Name             IP Address           Admin  Oper  Vrf  Description
---------------------------------------------------------------------
    eth0  fe80::dcad:beff:feef:6c20/64  up     up
eth0.200  20.0.0.50/24                  up     up
          fe80::dcad:beff:feef:6c20/64
    eth1                                down   down

---

Test DHCP Relay With Giaddr

Description

This example demonstrates how to set the gateway IP address (giaddr) in the IP address. This value must be set in an IP address that the DHCP server can reach.

Scenario

Step 1: Set the following configuration in DUT0 :

set interfaces ethernet eth0 vif 100 address 10.0.0.2/24
set interfaces ethernet eth1 vif 200 address 20.0.0.2/24
set interfaces ethernet eth1 vif 200 address 20.0.0.3/24
set service dhcp-relay INS downstream-interface eth1.200
set service dhcp-relay INS server 10.0.0.1 giaddr 20.0.0.3
set service dhcp-relay INS upstream-interface eth0.100
set system login user admin authentication encrypted-password '$6$GSjsCj8gHLv$/VcqU6FLi6CT2Oxn0MJQ2C2tqnRDrYKNF8HIYWJp68nvXvPdFccDsT04.WtigUONbKYrgKg8d6rEs8PjljMkH0'

Step 2: Set the following configuration in DUT1 :

set interfaces ethernet eth0 vif 100 address 10.0.0.1/24
set protocols static route 0.0.0.0/0 next-hop 10.0.0.2
set service dhcp-server shared-network dummy subnet 10.0.0.1/32
set service dhcp-server shared-network remote subnet 20.0.0.0/24 start 20.0.0.50 stop 20.0.0.50
set system login user admin authentication encrypted-password '$6$GSjsCj8gHLv$/VcqU6FLi6CT2Oxn0MJQ2C2tqnRDrYKNF8HIYWJp68nvXvPdFccDsT04.WtigUONbKYrgKg8d6rEs8PjljMkH0'

Step 3: Set the following configuration in DUT2 :

set interfaces ethernet eth0 vif 200 address dhcp
set system login user admin authentication encrypted-password '$6$GSjsCj8gHLv$/VcqU6FLi6CT2Oxn0MJQ2C2tqnRDrYKNF8HIYWJp68nvXvPdFccDsT04.WtigUONbKYrgKg8d6rEs8PjljMkH0'

Step 4: Ping IP address 10.0.0.1 from DUT0:

admin@DUT0$ ping 10.0.0.1 count 1 size 56 timeout 1

Show output

PING 10.0.0.1 (10.0.0.1) 56(84) bytes of data.
64 bytes from 10.0.0.1: icmp_seq=1 ttl=64 time=0.279 ms

--- 10.0.0.1 ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 0.279/0.279/0.279/0.000 ms

Step 5: Run command interfaces ethernet show at DUT2 and check if output contains the following tokens:

20.0.0.50

Show output

---------------------------------------------------------------------
  Name             IP Address           Admin  Oper  Vrf  Description
---------------------------------------------------------------------
    eth0  fe80::dcad:beff:feef:6c20/64  up     up
eth0.200  20.0.0.50/24                  up     up
          fe80::dcad:beff:feef:6c20/64
    eth1                                down   down

Step 6: Run command system journal show | cat at DUT1 and check if output matches the following regular expressions:

DHCPACK on 20.0.0.50 to [^\)]+\) via 20.0.0.3

Show output

Jul 28 09:57:15.448996 osdx systemd-journald[1575]: Runtime Journal (/run/log/journal/f2423ef2694c4ab083bba56aa5a0f772) is 1.8M, max 7.2M, 5.4M free.
Jul 28 09:57:15.450881 osdx systemd-journald[1575]: Received client request to rotate journal, rotating.
Jul 28 09:57:15.450962 osdx systemd-journald[1575]: Vacuuming done, freed 0B of archived journals from /run/log/journal/f2423ef2694c4ab083bba56aa5a0f772.
Jul 28 09:57:15.465875 osdx OSDxCLI[1850]: User 'admin' executed a new command: 'system journal clear'.
Jul 28 09:57:15.810187 osdx OSDxCLI[1850]: User 'admin' executed a new command: 'system coredump delete all'.
Jul 28 09:57:19.040367 osdx OSDxCLI[1850]: User 'admin' entered the configuration menu.
Jul 28 09:57:19.238124 osdx OSDxCLI[1850]: User 'admin' added a new cfg line: 'set interfaces eth0.100 address 10.0.0.1/24'.
Jul 28 09:57:19.418750 osdx OSDxCLI[1850]: User 'admin' added a new cfg line: 'set service dhcp-server shared-network dummy subnet 10.0.0.1/32'.
Jul 28 09:57:19.628381 osdx OSDxCLI[1850]: User 'admin' added a new cfg line: 'set service dhcp-server shared-network remote subnet 20.0.0.0/24 start 20.0.0.50 stop 20.0.0.50'.
Jul 28 09:57:19.836412 osdx OSDxCLI[1850]: User 'admin' added a new cfg line: 'set protocols static route 0.0.0.0/0 next-hop 10.0.0.2'.
Jul 28 09:57:20.118858 osdx OSDxCLI[1850]: User 'admin' added a new cfg line: 'show working'.
Jul 28 09:57:20.264041 osdx ubnt-cfgd[107700]: inactive
Jul 28 09:57:20.320629 osdx INFO[107710]: FRR daemons did not change
Jul 28 09:57:20.354116 osdx kernel: 8021q: adding VLAN 0 to HW filter on device eth0
Jul 28 09:57:20.390420 osdx (udev-worker)[107757]: Network interface NamePolicy= disabled on kernel command line.
Jul 28 09:57:20.638692 osdx systemd[1]: Started dhcpd@main.service - "DHCP Server Service instance main".
Jul 28 09:57:20.641371 osdx cfgd[1277]: [1850]Completed change to active configuration
Jul 28 09:57:20.644253 osdx dhcpd[107831]: Wrote 0 leases to leases file.
Jul 28 09:57:20.660186 osdx OSDxCLI[1850]: User 'admin' committed the configuration.
Jul 28 09:57:20.680967 osdx dhcpd[107831]:
Jul 28 09:57:20.680983 osdx dhcpd[107831]: No subnet declaration for eth0 (no IPv4 addresses).
Jul 28 09:57:20.680988 osdx dhcpd[107831]: ** Ignoring requests on eth0.  If this is not what
Jul 28 09:57:20.680992 osdx dhcpd[107831]:    you want, please write a subnet declaration
Jul 28 09:57:20.680995 osdx dhcpd[107831]:    in your dhcpd.conf file for the network segment
Jul 28 09:57:20.681000 osdx dhcpd[107831]:    to which interface eth0 is attached. **
Jul 28 09:57:20.681004 osdx dhcpd[107831]:
Jul 28 09:57:20.694271 osdx dhcpd[107831]: Server starting service.
Jul 28 09:57:20.705740 osdx OSDxCLI[1850]: User 'admin' left the configuration menu.
Jul 28 09:57:21.658315 osdx dhcpd[107831]: DHCPDISCOVER from de:ad:be:ef:6c:20 via 20.0.0.3
Jul 28 09:57:22.658813 osdx dhcpd[107831]: DHCPOFFER on 20.0.0.50 to de:ad:be:ef:6c:20 (osdx) via 20.0.0.3
Jul 28 09:57:22.659590 osdx dhcpd[107831]: DHCPREQUEST for 20.0.0.50 (10.0.0.1) from de:ad:be:ef:6c:20 (osdx) via 20.0.0.3
Jul 28 09:57:22.721016 osdx dhcpd[107831]: DHCPACK on 20.0.0.50 to de:ad:be:ef:6c:20 (osdx) via 20.0.0.3

---

Test DHCP Relay With GRE Tunnel

Description

This example demonstrates how to configure a DHCP relay that forwards DHCP requests to the DHCP server through a GRE tunnel (upstream).

Scenario

Step 1: Set the following configuration in DUT0 :

set interfaces ethernet eth0 vif 100 address 10.0.0.2/24
set interfaces ethernet eth1 vif 200 address 20.0.0.2/24
set interfaces tunnel tun1 address 1.0.0.2/32
set interfaces tunnel tun1 encapsulation gre
set interfaces tunnel tun1 local-address 10.0.0.2
set interfaces tunnel tun1 local-interface eth0.100
set interfaces tunnel tun1 nhrp holdtime 5
set interfaces tunnel tun1 nhrp nhs 1.0.0.1 nbma 10.0.0.1
set service dhcp-relay INS downstream-interface eth1.200
set service dhcp-relay INS server 1.0.0.1
set service dhcp-relay INS upstream-interface eth0.100
set service dhcp-relay INS upstream-interface tun1
set system login user admin authentication encrypted-password '$6$GSjsCj8gHLv$/VcqU6FLi6CT2Oxn0MJQ2C2tqnRDrYKNF8HIYWJp68nvXvPdFccDsT04.WtigUONbKYrgKg8d6rEs8PjljMkH0'

Step 2: Set the following configuration in DUT1 :

set interfaces ethernet eth0 vif 100 address 10.0.0.1/24
set interfaces tunnel tun1 address 1.0.0.1/32
set interfaces tunnel tun1 encapsulation gre
set interfaces tunnel tun1 local-address 10.0.0.1
set interfaces tunnel tun1 local-interface eth0.100
set interfaces tunnel tun1 nhrp
set protocols static route 0.0.0.0/0 next-hop 10.0.0.2
set protocols static route 20.0.0.0/24 next-hop 1.0.0.2
set service dhcp-server shared-network dummy subnet 1.0.0.1/32
set service dhcp-server shared-network remote subnet 20.0.0.0/24 start 20.0.0.50 stop 20.0.0.50
set system login user admin authentication encrypted-password '$6$GSjsCj8gHLv$/VcqU6FLi6CT2Oxn0MJQ2C2tqnRDrYKNF8HIYWJp68nvXvPdFccDsT04.WtigUONbKYrgKg8d6rEs8PjljMkH0'

Step 3: Set the following configuration in DUT2 :

set interfaces ethernet eth0 vif 200 address dhcp
set system login user admin authentication encrypted-password '$6$GSjsCj8gHLv$/VcqU6FLi6CT2Oxn0MJQ2C2tqnRDrYKNF8HIYWJp68nvXvPdFccDsT04.WtigUONbKYrgKg8d6rEs8PjljMkH0'

Step 4: Ping IP address 10.0.0.1 from DUT0:

admin@DUT0$ ping 10.0.0.1 count 1 size 56 timeout 1

Show output

PING 10.0.0.1 (10.0.0.1) 56(84) bytes of data.
64 bytes from 10.0.0.1: icmp_seq=1 ttl=64 time=2.07 ms

--- 10.0.0.1 ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 2.070/2.070/2.070/0.000 ms

Step 5: Ping IP address 1.0.0.1 from DUT0:

admin@DUT0$ ping 1.0.0.1 count 1 size 56 timeout 1

Show output

PING 1.0.0.1 (1.0.0.1) 56(84) bytes of data.
64 bytes from 1.0.0.1: icmp_seq=1 ttl=64 time=0.370 ms

--- 1.0.0.1 ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 0.370/0.370/0.370/0.000 ms

Step 6: Run command interfaces ethernet show at DUT2 and check if output contains the following tokens:

20.0.0.50

Show output

---------------------------------------------------------------------
  Name             IP Address           Admin  Oper  Vrf  Description
---------------------------------------------------------------------
    eth0  fe80::dcad:beff:feef:6c20/64  up     up
eth0.200  20.0.0.50/24                  up     up
          fe80::dcad:beff:feef:6c20/64
    eth1                                down   down

---

Test DHCP Relay With Multiple Instances

Description

This example demonstrates how to configure multiple DHCP relay instances.

Scenario

Step 1: Set the following configuration in DUT0 :

set interfaces ethernet eth0 vif 100 address 10.0.0.2/24
set interfaces ethernet eth1 vif 200 address 20.0.0.2/24
set interfaces ethernet eth1 vif 300 address 30.0.0.2/24
set service dhcp-relay INS downstream-interface eth1.200
set service dhcp-relay INS server 10.0.0.1
set service dhcp-relay INS upstream-interface eth0.100
set service dhcp-relay INS2 downstream-interface eth1.300
set service dhcp-relay INS2 server 10.0.0.1
set service dhcp-relay INS2 upstream-interface eth0.100
set system login user admin authentication encrypted-password '$6$GSjsCj8gHLv$/VcqU6FLi6CT2Oxn0MJQ2C2tqnRDrYKNF8HIYWJp68nvXvPdFccDsT04.WtigUONbKYrgKg8d6rEs8PjljMkH0'

Step 2: Set the following configuration in DUT1 :

set interfaces ethernet eth0 vif 100 address 10.0.0.1/24
set protocols static route 0.0.0.0/0 next-hop 10.0.0.2
set service dhcp-server shared-network dummy subnet 10.0.0.1/32
set service dhcp-server shared-network remote subnet 20.0.0.0/24 start 20.0.0.50 stop 20.0.0.50
set service dhcp-server shared-network remote2 subnet 30.0.0.0/24 start 30.0.0.50 stop 30.0.0.50
set system login user admin authentication encrypted-password '$6$GSjsCj8gHLv$/VcqU6FLi6CT2Oxn0MJQ2C2tqnRDrYKNF8HIYWJp68nvXvPdFccDsT04.WtigUONbKYrgKg8d6rEs8PjljMkH0'

Step 3: Set the following configuration in DUT2 :

set interfaces ethernet eth0 vif 200 address dhcp
set interfaces ethernet eth0 vif 300 address dhcp
set system login user admin authentication encrypted-password '$6$GSjsCj8gHLv$/VcqU6FLi6CT2Oxn0MJQ2C2tqnRDrYKNF8HIYWJp68nvXvPdFccDsT04.WtigUONbKYrgKg8d6rEs8PjljMkH0'

Step 4: Ping IP address 10.0.0.1 from DUT0:

admin@DUT0$ ping 10.0.0.1 count 1 size 56 timeout 1

Show output

PING 10.0.0.1 (10.0.0.1) 56(84) bytes of data.
64 bytes from 10.0.0.1: icmp_seq=1 ttl=64 time=0.302 ms

--- 10.0.0.1 ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 0.302/0.302/0.302/0.000 ms

Step 5: Run command interfaces ethernet show at DUT2 and check if output contains the following tokens:

20.0.0.50

Show output

---------------------------------------------------------------------
  Name             IP Address           Admin  Oper  Vrf  Description
---------------------------------------------------------------------
    eth0  fe80::dcad:beff:feef:6c20/64  up     up
eth0.200  20.0.0.50/24                  up     up
          fe80::dcad:beff:feef:6c20/64
eth0.300  30.0.0.50/24                  up     up
          fe80::dcad:beff:feef:6c20/64
    eth1                                down   down

Step 6: Run command interfaces ethernet show at DUT2 and check if output contains the following tokens:

30.0.0.50

Show output

---------------------------------------------------------------------
  Name             IP Address           Admin  Oper  Vrf  Description
---------------------------------------------------------------------
    eth0  fe80::dcad:beff:feef:6c20/64  up     up
eth0.200  20.0.0.50/24                  up     up
          fe80::dcad:beff:feef:6c20/64
eth0.300  30.0.0.50/24                  up     up
          fe80::dcad:beff:feef:6c20/64
    eth1                                down   down

Step 7: Run command system journal show | cat at DUT1 and check if output matches the following regular expressions:

DHCPACK on 20.0.0.50 to [^\)]+\) via 20.0.0.2
DHCPACK on 30.0.0.50 to [^\)]+\) via 30.0.0.2

Show output

Jul 28 09:57:56.543025 osdx systemd-journald[1575]: Runtime Journal (/run/log/journal/f2423ef2694c4ab083bba56aa5a0f772) is 1.0M, max 7.2M, 6.2M free.
Jul 28 09:57:56.545212 osdx systemd-journald[1575]: Received client request to rotate journal, rotating.
Jul 28 09:57:56.545307 osdx systemd-journald[1575]: Vacuuming done, freed 0B of archived journals from /run/log/journal/f2423ef2694c4ab083bba56aa5a0f772.
Jul 28 09:57:56.561778 osdx OSDxCLI[1850]: User 'admin' executed a new command: 'system journal clear'.
Jul 28 09:57:57.130414 osdx OSDxCLI[1850]: User 'admin' executed a new command: 'system coredump delete all'.
Jul 28 09:58:01.804858 osdx OSDxCLI[1850]: User 'admin' entered the configuration menu.
Jul 28 09:58:01.967063 osdx OSDxCLI[1850]: User 'admin' added a new cfg line: 'set interfaces eth0.100 address 10.0.0.1/24'.
Jul 28 09:58:02.125223 osdx OSDxCLI[1850]: User 'admin' added a new cfg line: 'set service dhcp-server shared-network dummy subnet 10.0.0.1/32'.
Jul 28 09:58:02.250091 osdx OSDxCLI[1850]: User 'admin' added a new cfg line: 'set service dhcp-server shared-network remote subnet 20.0.0.0/24 start 20.0.0.50 stop 20.0.0.50'.
Jul 28 09:58:02.448413 osdx OSDxCLI[1850]: User 'admin' added a new cfg line: 'set protocols static route 0.0.0.0/0 next-hop 10.0.0.2'.
Jul 28 09:58:02.624398 osdx OSDxCLI[1850]: User 'admin' added a new cfg line: 'set service dhcp-server shared-network remote2 subnet 30.0.0.0/24 start 30.0.0.50 stop 30.0.0.50'.
Jul 28 09:58:02.872636 osdx OSDxCLI[1850]: User 'admin' added a new cfg line: 'show working'.
Jul 28 09:58:03.002210 osdx ubnt-cfgd[108660]: inactive
Jul 28 09:58:03.079507 osdx INFO[108672]: FRR daemons did not change
Jul 28 09:58:03.121205 osdx kernel: 8021q: adding VLAN 0 to HW filter on device eth0
Jul 28 09:58:03.218627 osdx (udev-worker)[108719]: Network interface NamePolicy= disabled on kernel command line.
Jul 28 09:58:03.555096 osdx systemd[1]: Started dhcpd@main.service - "DHCP Server Service instance main".
Jul 28 09:58:03.560253 osdx cfgd[1277]: [1850]Completed change to active configuration
Jul 28 09:58:03.574453 osdx dhcpd[108793]: Wrote 0 leases to leases file.
Jul 28 09:58:03.582665 osdx OSDxCLI[1850]: User 'admin' committed the configuration.
Jul 28 09:58:03.626269 osdx dhcpd[108793]:
Jul 28 09:58:03.626279 osdx dhcpd[108793]: No subnet declaration for eth0 (no IPv4 addresses).
Jul 28 09:58:03.626284 osdx dhcpd[108793]: ** Ignoring requests on eth0.  If this is not what
Jul 28 09:58:03.626288 osdx dhcpd[108793]:    you want, please write a subnet declaration
Jul 28 09:58:03.626292 osdx dhcpd[108793]:    in your dhcpd.conf file for the network segment
Jul 28 09:58:03.626296 osdx dhcpd[108793]:    to which interface eth0 is attached. **
Jul 28 09:58:03.626301 osdx dhcpd[108793]:
Jul 28 09:58:03.637343 osdx dhcpd[108793]: Server starting service.
Jul 28 09:58:03.638686 osdx OSDxCLI[1850]: User 'admin' left the configuration menu.
Jul 28 09:58:05.113976 osdx dhcpd[108793]: DHCPDISCOVER from de:ad:be:ef:6c:20 via 20.0.0.2
Jul 28 09:58:05.470612 osdx dhcpd[108793]: DHCPDISCOVER from de:ad:be:ef:6c:20 via 30.0.0.2
Jul 28 09:58:06.114259 osdx dhcpd[108793]: DHCPOFFER on 20.0.0.50 to de:ad:be:ef:6c:20 (osdx) via 20.0.0.2
Jul 28 09:58:06.116317 osdx dhcpd[108793]: DHCPREQUEST for 20.0.0.50 (10.0.0.1) from de:ad:be:ef:6c:20 (osdx) via 20.0.0.2
Jul 28 09:58:06.227933 osdx dhcpd[108793]: DHCPACK on 20.0.0.50 to de:ad:be:ef:6c:20 (osdx) via 20.0.0.2
Jul 28 09:58:06.470842 osdx dhcpd[108793]: DHCPOFFER on 30.0.0.50 to de:ad:be:ef:6c:20 (osdx) via 30.0.0.2
Jul 28 09:58:06.471974 osdx dhcpd[108793]: DHCPREQUEST for 30.0.0.50 (10.0.0.1) from de:ad:be:ef:6c:20 (osdx) via 30.0.0.2
Jul 28 09:58:06.495310 osdx dhcpd[108793]: DHCPACK on 30.0.0.50 to de:ad:be:ef:6c:20 (osdx) via 30.0.0.2

---