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=0.219 ms

--- 10.0.0.1 ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 0.219/0.219/0.219/0.000 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=0.278 ms

--- 10.0.0.1 ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 0.278/0.278/0.278/0.000 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

Jun 24 14:05:55.346045 osdx systemd-journald[1554]: Runtime Journal (/run/log/journal/c46306ce94da41d08ec4fbe6b50ef5f9) is 1.0M, max 7.2M, 6.2M free.
Jun 24 14:05:55.346781 osdx systemd-journald[1554]: Received client request to rotate journal, rotating.
Jun 24 14:05:55.346833 osdx systemd-journald[1554]: Vacuuming done, freed 0B of archived journals from /run/log/journal/c46306ce94da41d08ec4fbe6b50ef5f9.
Jun 24 14:05:55.357991 osdx OSDxCLI[143450]: User 'admin' executed a new command: 'system journal clear'.
Jun 24 14:05:55.562705 osdx OSDxCLI[143450]: User 'admin' executed a new command: 'system coredump delete all'.
Jun 24 14:05:56.949962 osdx OSDxCLI[143450]: User 'admin' entered the configuration menu.
Jun 24 14:05:57.037033 osdx OSDxCLI[143450]: User 'admin' added a new cfg line: 'set interfaces eth0.100 address 10.0.0.1/24'.
Jun 24 14:05:57.129752 osdx OSDxCLI[143450]: User 'admin' added a new cfg line: 'set service dhcp-server shared-network dummy subnet 10.0.0.1/32'.
Jun 24 14:05:57.189579 osdx OSDxCLI[143450]: 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'.
Jun 24 14:05:57.286542 osdx OSDxCLI[143450]: User 'admin' added a new cfg line: 'set protocols static route 0.0.0.0/0 next-hop 10.0.0.2'.
Jun 24 14:05:57.355903 osdx OSDxCLI[143450]: User 'admin' added a new cfg line: 'show working'.
Jun 24 14:05:57.454876 osdx ubnt-cfgd[190387]: inactive
Jun 24 14:05:57.479493 osdx INFO[190397]: FRR daemons did not change
Jun 24 14:05:57.502815 osdx kernel: 8021q: adding VLAN 0 to HW filter on device eth0
Jun 24 14:05:57.520536 osdx (udev-worker)[190446]: Network interface NamePolicy= disabled on kernel command line.
Jun 24 14:05:57.671246 osdx systemd[1]: Started dhcpd@main.service - "DHCP Server Service instance main".
Jun 24 14:05:57.674342 osdx cfgd[1254]: [143450]Completed change to active configuration
Jun 24 14:05:57.674517 osdx dhcpd[190514]: Wrote 0 leases to leases file.
Jun 24 14:05:57.689257 osdx OSDxCLI[143450]: User 'admin' committed the configuration.
Jun 24 14:05:57.691217 osdx dhcpd[190514]:
Jun 24 14:05:57.691222 osdx dhcpd[190514]: No subnet declaration for eth0 (no IPv4 addresses).
Jun 24 14:05:57.691225 osdx dhcpd[190514]: ** Ignoring requests on eth0.  If this is not what
Jun 24 14:05:57.691227 osdx dhcpd[190514]:    you want, please write a subnet declaration
Jun 24 14:05:57.691229 osdx dhcpd[190514]:    in your dhcpd.conf file for the network segment
Jun 24 14:05:57.691232 osdx dhcpd[190514]:    to which interface eth0 is attached. **
Jun 24 14:05:57.691234 osdx dhcpd[190514]:
Jun 24 14:05:57.702910 osdx dhcpd[190514]: Server starting service.
Jun 24 14:05:57.707643 osdx OSDxCLI[143450]: User 'admin' left the configuration menu.
Jun 24 14:05:58.343227 osdx dhcpd[190514]: DHCPDISCOVER from de:ad:be:ef:6c:20 via 20.0.0.3
Jun 24 14:05:59.343350 osdx dhcpd[190514]: DHCPOFFER on 20.0.0.50 to de:ad:be:ef:6c:20 (osdx) via 20.0.0.3
Jun 24 14:05:59.343947 osdx dhcpd[190514]: DHCPREQUEST for 20.0.0.50 (10.0.0.1) from de:ad:be:ef:6c:20 (osdx) via 20.0.0.3
Jun 24 14:05:59.383095 osdx dhcpd[190514]: 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=0.229 ms

--- 10.0.0.1 ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 0.229/0.229/0.229/0.000 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=0.279 ms

--- 1.0.0.1 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 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=0.284 ms

--- 10.0.0.1 ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 0.284/0.284/0.284/0.000 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

Jun 24 14:06:19.279472 osdx systemd-journald[1554]: Runtime Journal (/run/log/journal/c46306ce94da41d08ec4fbe6b50ef5f9) is 1.0M, max 7.2M, 6.2M free.
Jun 24 14:06:19.282297 osdx systemd-journald[1554]: Received client request to rotate journal, rotating.
Jun 24 14:06:19.282368 osdx systemd-journald[1554]: Vacuuming done, freed 0B of archived journals from /run/log/journal/c46306ce94da41d08ec4fbe6b50ef5f9.
Jun 24 14:06:19.289308 osdx OSDxCLI[143450]: User 'admin' executed a new command: 'system journal clear'.
Jun 24 14:06:19.545235 osdx OSDxCLI[143450]: User 'admin' executed a new command: 'system coredump delete all'.
Jun 24 14:06:21.257795 osdx OSDxCLI[143450]: User 'admin' entered the configuration menu.
Jun 24 14:06:21.333980 osdx OSDxCLI[143450]: User 'admin' added a new cfg line: 'set interfaces eth0.100 address 10.0.0.1/24'.
Jun 24 14:06:21.426490 osdx OSDxCLI[143450]: User 'admin' added a new cfg line: 'set service dhcp-server shared-network dummy subnet 10.0.0.1/32'.
Jun 24 14:06:21.486394 osdx OSDxCLI[143450]: 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'.
Jun 24 14:06:21.577860 osdx OSDxCLI[143450]: User 'admin' added a new cfg line: 'set protocols static route 0.0.0.0/0 next-hop 10.0.0.2'.
Jun 24 14:06:21.652164 osdx OSDxCLI[143450]: 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'.
Jun 24 14:06:21.772339 osdx OSDxCLI[143450]: User 'admin' added a new cfg line: 'show working'.
Jun 24 14:06:21.855306 osdx ubnt-cfgd[191333]: inactive
Jun 24 14:06:21.894485 osdx INFO[191345]: FRR daemons did not change
Jun 24 14:06:21.918286 osdx kernel: 8021q: adding VLAN 0 to HW filter on device eth0
Jun 24 14:06:21.940262 osdx (udev-worker)[191394]: Network interface NamePolicy= disabled on kernel command line.
Jun 24 14:06:22.126629 osdx systemd[1]: Started dhcpd@main.service - "DHCP Server Service instance main".
Jun 24 14:06:22.128462 osdx cfgd[1254]: [143450]Completed change to active configuration
Jun 24 14:06:22.130173 osdx dhcpd[191462]: Wrote 0 leases to leases file.
Jun 24 14:06:22.139886 osdx OSDxCLI[143450]: User 'admin' committed the configuration.
Jun 24 14:06:22.152885 osdx dhcpd[191462]:
Jun 24 14:06:22.152891 osdx dhcpd[191462]: No subnet declaration for eth0 (no IPv4 addresses).
Jun 24 14:06:22.152893 osdx dhcpd[191462]: ** Ignoring requests on eth0.  If this is not what
Jun 24 14:06:22.152895 osdx dhcpd[191462]:    you want, please write a subnet declaration
Jun 24 14:06:22.152898 osdx dhcpd[191462]:    in your dhcpd.conf file for the network segment
Jun 24 14:06:22.152900 osdx dhcpd[191462]:    to which interface eth0 is attached. **
Jun 24 14:06:22.152903 osdx dhcpd[191462]:
Jun 24 14:06:22.158463 osdx dhcpd[191462]: Server starting service.
Jun 24 14:06:22.170564 osdx OSDxCLI[143450]: User 'admin' left the configuration menu.
Jun 24 14:06:22.930713 osdx dhcpd[191462]: DHCPDISCOVER from de:ad:be:ef:6c:20 via 20.0.0.2
Jun 24 14:06:23.078497 osdx dhcpd[191462]: DHCPDISCOVER from de:ad:be:ef:6c:20 via 30.0.0.2
Jun 24 14:06:23.930876 osdx dhcpd[191462]: DHCPOFFER on 20.0.0.50 to de:ad:be:ef:6c:20 (osdx) via 20.0.0.2
Jun 24 14:06:23.931610 osdx dhcpd[191462]: DHCPREQUEST for 20.0.0.50 (10.0.0.1) from de:ad:be:ef:6c:20 (osdx) via 20.0.0.2
Jun 24 14:06:23.969792 osdx dhcpd[191462]: DHCPACK on 20.0.0.50 to de:ad:be:ef:6c:20 (osdx) via 20.0.0.2
Jun 24 14:06:24.078729 osdx dhcpd[191462]: DHCPOFFER on 30.0.0.50 to de:ad:be:ef:6c:20 (osdx) via 30.0.0.2
Jun 24 14:06:24.079428 osdx dhcpd[191462]: DHCPREQUEST for 30.0.0.50 (10.0.0.1) from de:ad:be:ef:6c:20 (osdx) via 30.0.0.2
Jun 24 14:06:24.089777 osdx dhcpd[191462]: DHCPACK on 30.0.0.50 to de:ad:be:ef:6c:20 (osdx) via 30.0.0.2

---