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=0.240 ms

--- 10.0.0.1 ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 0.240/0.240/0.240/0.000 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
Mar 24 12:57:27.269116 osdx systemd-journald[1562]: Runtime Journal (/run/log/journal/4697983b28394fbab81ced9284dd096a) is 936.0K, max 6.5M, 5.6M free.
Mar 24 12:57:27.271325 osdx systemd-journald[1562]: Received client request to rotate journal, rotating.
Mar 24 12:57:27.271374 osdx systemd-journald[1562]: Vacuuming done, freed 0B of archived journals from /run/log/journal/4697983b28394fbab81ced9284dd096a.
Mar 24 12:57:27.279010 osdx OSDxCLI[198564]: User 'admin' executed a new command: 'system journal clear'.
Mar 24 12:57:27.469947 osdx OSDxCLI[198564]: User 'admin' executed a new command: 'system coredump delete all'.
Mar 24 12:57:28.769814 osdx OSDxCLI[198564]: User 'admin' entered the configuration menu.
Mar 24 12:57:28.854068 osdx OSDxCLI[198564]: User 'admin' added a new cfg line: 'set interfaces eth0.100 address 10.0.0.1/24'.
Mar 24 12:57:28.956880 osdx OSDxCLI[198564]: User 'admin' added a new cfg line: 'set service dhcp-server shared-network dummy subnet 10.0.0.1/32'.
Mar 24 12:57:29.021639 osdx OSDxCLI[198564]: 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'.
Mar 24 12:57:29.139438 osdx OSDxCLI[198564]: User 'admin' added a new cfg line: 'set protocols static route 0.0.0.0/0 next-hop 10.0.0.2'.
Mar 24 12:57:29.237146 osdx OSDxCLI[198564]: User 'admin' added a new cfg line: 'set traffic policy LOGGER rule 1 log prefix DHCP_'.
Mar 24 12:57:29.342047 osdx OSDxCLI[198564]: User 'admin' added a new cfg line: 'set traffic policy LOGGER rule 1 selector UDP'.
Mar 24 12:57:29.415566 osdx OSDxCLI[198564]: User 'admin' added a new cfg line: 'set traffic selector UDP rule 1 protocol udp'.
Mar 24 12:57:29.533044 osdx OSDxCLI[198564]: User 'admin' added a new cfg line: 'set traffic selector UDP rule 1 destination port 67'.
Mar 24 12:57:29.594298 osdx OSDxCLI[198564]: User 'admin' added a new cfg line: 'set interfaces eth0.100 traffic policy in LOGGER'.
Mar 24 12:57:29.701730 osdx OSDxCLI[198564]: User 'admin' added a new cfg line: 'show working'.
Mar 24 12:57:29.765409 osdx ubnt-cfgd[301988]: inactive
Mar 24 12:57:29.855595 osdx INFO[302013]: FRR daemons did not change
Mar 24 12:57:29.887328 osdx kernel: 8021q: adding VLAN 0 to HW filter on device eth0
Mar 24 12:57:29.907947 osdx (udev-worker)[302060]: Network interface NamePolicy= disabled on kernel command line.
Mar 24 12:57:30.187665 osdx systemd[1]: Started dhcpd@main.service - "DHCP Server Service instance main".
Mar 24 12:57:30.189792 osdx cfgd[1263]: [198564]Completed change to active configuration
Mar 24 12:57:30.192179 osdx dhcpd[302154]: Wrote 0 leases to leases file.
Mar 24 12:57:30.202545 osdx OSDxCLI[198564]: User 'admin' committed the configuration.
Mar 24 12:57:30.233275 osdx OSDxCLI[198564]: User 'admin' left the configuration menu.
Mar 24 12:57:30.257737 osdx dhcpd[302154]:
Mar 24 12:57:30.257744 osdx dhcpd[302154]: No subnet declaration for eth0 (no IPv4 addresses).
Mar 24 12:57:30.257746 osdx dhcpd[302154]: ** Ignoring requests on eth0.  If this is not what
Mar 24 12:57:30.257749 osdx dhcpd[302154]:    you want, please write a subnet declaration
Mar 24 12:57:30.257751 osdx dhcpd[302154]:    in your dhcpd.conf file for the network segment
Mar 24 12:57:30.257754 osdx dhcpd[302154]:    to which interface eth0 is attached. **
Mar 24 12:57:30.257759 osdx dhcpd[302154]:
Mar 24 12:57:30.279549 osdx dhcpd[302154]: Server starting service.
Mar 24 12:57:30.849372 osdx dhcpd[302154]: DHCPDISCOVER from de:ad:be:ef:6c:20 via 20.0.0.2
Mar 24 12:57:30.851332 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=14354 DF PROTO=UDP SPT=67 DPT=67 LEN=308
Mar 24 12:57:31.850040 osdx dhcpd[302154]: DHCPOFFER on 20.0.0.50 to de:ad:be:ef:6c:20 (osdx) via 20.0.0.2
Mar 24 12:57:31.850835 osdx dhcpd[302154]: DHCPREQUEST for 20.0.0.50 (10.0.0.1) from de:ad:be:ef:6c:20 (osdx) via 20.0.0.2
Mar 24 12:57:31.851325 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=14413 DF PROTO=UDP SPT=67 DPT=67 LEN=308
Mar 24 12:57:31.892254 osdx dhcpd[302154]: DHCPACK on 20.0.0.50 to de:ad:be:ef:6c:20 (osdx) via 20.0.0.2