Local-Address

This scenario shows how to configure a DHCP relay agent to forward DHCP requests. By default, the local-address option uses a custom local IP as source address for upstream traffic.

../../../../_images/local.svg

Test DHCP Relay With Local-Address

Description

This example shows how to configure the local-address option. This command can be used to set the source address for upstream traffic.

Scenario

Step 1: Set the following configuration in DUT0 :

set interfaces dummy dum0 address 1.1.1.1/32
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 local-address 1.1.1.1
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 interfaces ethernet eth0 vif 100 traffic policy in LOGGER
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'
set traffic policy LOGGER rule 1 log prefix DHCP_
set traffic policy LOGGER rule 1 selector UDP
set traffic selector UDP rule 1 destination port 67
set traffic selector UDP rule 1 protocol udp

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=0.382 ms

--- 10.0.0.1 ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 0.382/0.382/0.382/0.000 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:

SRC=1.1.1.1 DST=10.0.0.1
Show output
Jul 28 09:59:18.426801 osdx systemd-journald[1575]: Runtime Journal (/run/log/journal/f2423ef2694c4ab083bba56aa5a0f772) is 1.0M, max 7.2M, 6.2M free.
Jul 28 09:59:18.429277 osdx systemd-journald[1575]: Received client request to rotate journal, rotating.
Jul 28 09:59:18.429382 osdx systemd-journald[1575]: Vacuuming done, freed 0B of archived journals from /run/log/journal/f2423ef2694c4ab083bba56aa5a0f772.
Jul 28 09:59:18.444774 osdx OSDxCLI[1850]: User 'admin' executed a new command: 'system journal clear'.
Jul 28 09:59:18.795809 osdx OSDxCLI[1850]: User 'admin' executed a new command: 'system coredump delete all'.
Jul 28 09:59:21.044480 osdx OSDxCLI[1850]: User 'admin' entered the configuration menu.
Jul 28 09:59:21.201970 osdx OSDxCLI[1850]: User 'admin' added a new cfg line: 'set interfaces eth0.100 address 10.0.0.1/24'.
Jul 28 09:59:21.294325 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 09:59:21.401222 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 09:59:21.508463 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 09:59:21.687329 osdx OSDxCLI[1850]: User 'admin' added a new cfg line: 'set traffic policy LOGGER rule 1 log prefix DHCP_'.
Jul 28 09:59:21.784359 osdx OSDxCLI[1850]: User 'admin' added a new cfg line: 'set traffic policy LOGGER rule 1 selector UDP'.
Jul 28 09:59:21.898292 osdx OSDxCLI[1850]: User 'admin' added a new cfg line: 'set traffic selector UDP rule 1 protocol udp'.
Jul 28 09:59:22.032125 osdx OSDxCLI[1850]: User 'admin' added a new cfg line: 'set traffic selector UDP rule 1 destination port 67'.
Jul 28 09:59:22.170648 osdx OSDxCLI[1850]: User 'admin' added a new cfg line: 'set interfaces eth0.100 traffic policy in LOGGER'.
Jul 28 09:59:22.313517 osdx OSDxCLI[1850]: User 'admin' added a new cfg line: 'show working'.
Jul 28 09:59:22.414413 osdx ubnt-cfgd[110288]: inactive
Jul 28 09:59:22.517576 osdx INFO[110313]: FRR daemons did not change
Jul 28 09:59:22.545254 osdx kernel: 8021q: adding VLAN 0 to HW filter on device eth0
Jul 28 09:59:22.574403 osdx (udev-worker)[110360]: Network interface NamePolicy= disabled on kernel command line.
Jul 28 09:59:23.137763 osdx systemd[1]: Started dhcpd@main.service - "DHCP Server Service instance main".
Jul 28 09:59:23.140750 osdx cfgd[1277]: [1850]Completed change to active configuration
Jul 28 09:59:23.144263 osdx dhcpd[110460]: Wrote 0 leases to leases file.
Jul 28 09:59:23.158184 osdx OSDxCLI[1850]: User 'admin' committed the configuration.
Jul 28 09:59:23.181526 osdx dhcpd[110460]:
Jul 28 09:59:23.181533 osdx dhcpd[110460]: No subnet declaration for eth0 (no IPv4 addresses).
Jul 28 09:59:23.181537 osdx dhcpd[110460]: ** Ignoring requests on eth0.  If this is not what
Jul 28 09:59:23.181541 osdx dhcpd[110460]:    you want, please write a subnet declaration
Jul 28 09:59:23.181544 osdx dhcpd[110460]:    in your dhcpd.conf file for the network segment
Jul 28 09:59:23.181548 osdx dhcpd[110460]:    to which interface eth0 is attached. **
Jul 28 09:59:23.181551 osdx dhcpd[110460]:
Jul 28 09:59:23.189337 osdx dhcpd[110460]: Server starting service.
Jul 28 09:59:23.197213 osdx OSDxCLI[1850]: User 'admin' left the configuration menu.
Jul 28 09:59:24.025249 osdx kernel: [DHCP_-1] ACCEPT IN=eth0.100 OUT= MAC=de:ad:be:ef:6c:10:de:ad:be:ef:6c:00:08:00:45:00:01:48 SRC=1.1.1.1 DST=10.0.0.1 LEN=328 TOS=0x00 PREC=0x00 TTL=64 ID=4929 DF PROTO=UDP SPT=67 DPT=67 LEN=308
Jul 28 09:59:24.025250 osdx dhcpd[110460]: DHCPDISCOVER from de:ad:be:ef:6c:20 via 20.0.0.2
Jul 28 09:59:25.025891 osdx dhcpd[110460]: DHCPOFFER on 20.0.0.50 to de:ad:be:ef:6c:20 (osdx) via 20.0.0.2
Jul 28 09:59:25.026690 osdx dhcpd[110460]: 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 09:59:25.029214 osdx kernel: [DHCP_-1] ACCEPT IN=eth0.100 OUT= MAC=de:ad:be:ef:6c:10:de:ad:be:ef:6c:00:08:00:45:00:01:48 SRC=1.1.1.1 DST=10.0.0.1 LEN=328 TOS=0x00 PREC=0x00 TTL=64 ID=5040 DF PROTO=UDP SPT=67 DPT=67 LEN=308
Jul 28 09:59:25.079810 osdx dhcpd[110460]: DHCPACK on 20.0.0.50 to de:ad:be:ef:6c:20 (osdx) via 20.0.0.2