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=0.182 ms

--- 10.0.0.1 ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 0.182/0.182/0.182/0.000 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
Oct 10 23:00:16.247310 osdx systemd-journald[1561]: Runtime Journal (/run/log/journal/806ba4d037ed4b398e58eb92edf93777) is 964.0K, max 6.5M, 5.5M free.
Oct 10 23:00:16.250627 osdx systemd-journald[1561]: Received client request to rotate journal, rotating.
Oct 10 23:00:16.250688 osdx systemd-journald[1561]: Vacuuming done, freed 0B of archived journals from /run/log/journal/806ba4d037ed4b398e58eb92edf93777.
Oct 10 23:00:16.257566 osdx OSDxCLI[129632]: User 'admin' executed a new command: 'system journal clear'.
Oct 10 23:00:16.490994 osdx OSDxCLI[129632]: User 'admin' executed a new command: 'system coredump delete all'.
Oct 10 23:00:17.771771 osdx OSDxCLI[129632]: User 'admin' entered the configuration menu.
Oct 10 23:00:17.840054 osdx OSDxCLI[129632]: User 'admin' added a new cfg line: 'set interfaces eth0.100 address 10.0.0.1/24'.
Oct 10 23:00:17.921205 osdx OSDxCLI[129632]: User 'admin' added a new cfg line: 'set service dhcp-server shared-network dummy subnet 10.0.0.1/32'.
Oct 10 23:00:17.978436 osdx OSDxCLI[129632]: 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'.
Oct 10 23:00:18.067586 osdx OSDxCLI[129632]: User 'admin' added a new cfg line: 'set protocols static route 0.0.0.0/0 next-hop 10.0.0.2'.
Oct 10 23:00:18.130331 osdx OSDxCLI[129632]: User 'admin' added a new cfg line: 'set traffic policy LOGGER rule 1 log prefix DHCP_'.
Oct 10 23:00:18.226007 osdx OSDxCLI[129632]: User 'admin' added a new cfg line: 'set traffic policy LOGGER rule 1 selector UDP'.
Oct 10 23:00:18.283225 osdx OSDxCLI[129632]: User 'admin' added a new cfg line: 'set traffic selector UDP rule 1 protocol udp'.
Oct 10 23:00:18.379064 osdx OSDxCLI[129632]: User 'admin' added a new cfg line: 'set traffic selector UDP rule 1 destination port 67'.
Oct 10 23:00:18.436825 osdx OSDxCLI[129632]: User 'admin' added a new cfg line: 'set interfaces eth0.100 traffic policy in LOGGER'.
Oct 10 23:00:18.551679 osdx OSDxCLI[129632]: User 'admin' added a new cfg line: 'show working'.
Oct 10 23:00:18.620680 osdx ubnt-cfgd[315818]: inactive
Oct 10 23:00:18.691025 osdx INFO[315843]: FRR daemons did not change
Oct 10 23:00:18.722634 osdx kernel: 8021q: adding VLAN 0 to HW filter on device eth0
Oct 10 23:00:18.745224 osdx (udev-worker)[315891]: Network interface NamePolicy= disabled on kernel command line.
Oct 10 23:00:19.018999 osdx systemd[1]: Started dhcpd@main.service - "DHCP Server Service instance main".
Oct 10 23:00:19.020848 osdx cfgd[1260]: [129632]Completed change to active configuration
Oct 10 23:00:19.021981 osdx dhcpd[315986]: Wrote 0 leases to leases file.
Oct 10 23:00:19.033680 osdx OSDxCLI[129632]: User 'admin' committed the configuration.
Oct 10 23:00:19.053111 osdx OSDxCLI[129632]: User 'admin' left the configuration menu.
Oct 10 23:00:19.085135 osdx dhcpd[315986]:
Oct 10 23:00:19.085141 osdx dhcpd[315986]: No subnet declaration for eth0 (no IPv4 addresses).
Oct 10 23:00:19.085144 osdx dhcpd[315986]: ** Ignoring requests on eth0.  If this is not what
Oct 10 23:00:19.085146 osdx dhcpd[315986]:    you want, please write a subnet declaration
Oct 10 23:00:19.085148 osdx dhcpd[315986]:    in your dhcpd.conf file for the network segment
Oct 10 23:00:19.085150 osdx dhcpd[315986]:    to which interface eth0 is attached. **
Oct 10 23:00:19.085153 osdx dhcpd[315986]:
Oct 10 23:00:19.098746 osdx dhcpd[315986]: Server starting service.
Oct 10 23:00:19.629332 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=44767 DF PROTO=UDP SPT=67 DPT=67 LEN=308
Oct 10 23:00:19.629413 osdx dhcpd[315986]: DHCPDISCOVER from de:ad:be:ef:6c:20 via 20.0.0.2
Oct 10 23:00:20.629799 osdx dhcpd[315986]: DHCPOFFER on 20.0.0.50 to de:ad:be:ef:6c:20 (osdx) via 20.0.0.2
Oct 10 23:00:20.630366 osdx dhcpd[315986]: DHCPREQUEST for 20.0.0.50 (10.0.0.1) from de:ad:be:ef:6c:20 (osdx) via 20.0.0.2
Oct 10 23:00:20.630636 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=44806 DF PROTO=UDP SPT=67 DPT=67 LEN=308
Oct 10 23:00:20.650766 osdx dhcpd[315986]: DHCPACK on 20.0.0.50 to de:ad:be:ef:6c:20 (osdx) via 20.0.0.2