OcNOS-SP : System Management Guide : System Management Configuration Guide : DHCP Relay Agent Configuration : Physical Interface Configuration with non-default VRF
Physical Interface Configuration with non-default VRF
Here, the DHCP Server is running with IP 192.168.1.2 with another pool of subnet 10.10.20.0 configured in the server. Configure a static route to 10.10.20.0 network for DHCP OFFER packets to reach the Relay Agent.
Relay agent
 
#configure terminal
Enter configure mode.
(config)#ip dhcp relay
Enable DHCP Relay.
(config)#ip vrf vrf_dhcp
Configuring non default vrf vrf_dhcp
(config-vrf)#ip dhcp relay information option remote-id hostname
Enable DHCP Relay information option with both agent circuit id which is sub option 1 of option 82 and remote-id which is sub option 2 of option 82 on non default vrf.. String support is also provided for remote-id.
(config-vrf)#ip dhcp relay address 192.168.1.2
Configure DHCP relay address in non default vrf.
(config)#interface xe5
Enter interface mode.
(config-if)#ip vrf forwarding vrf_dhcp
Configure vrf forwarding for vrf_dhcp.
(config-if)#ip address 10.10.20.2/24
Add IP address.
(config-if)#ip dhcp relay
Configure DHCP relay for the interface connecting to client.
(config-if)#exit
Exit from interface mode
(config)#commit
 
 
Commit the candidate configuration to the running configuration
(config)#interface xe4
Enter interface mode
(config-if)#ip vrf forwarding vrf_dhcp
Configure vrf forwarding for vrf_dhcp
(config-if)#ip dhcp relay uplink
Configure DHCP relay uplink for the interface connecting to server.
(config-if)#ip address 192.168.1.4/24
Add IP address.
(config-if)#exit
Exit interface mode.
(config)#commit
 
 
Commit the candidate configuration to the running configuration
 
Client
 
#configure terminal
Enter configure mode.
(config)#interface xe5
Enter interface mode.
(config-if)#ip vrf forwarding vrf_dhcp
Configure ip vrf forwarding for non default vrf.
(config-if)#ip address dhcp
Configure IP address DHCP.
(config-if)#exit
Exit from interface mode.
(config)#commit
 
 
Commit the candidate configuration to the running configuration
Validation
Relay Agent
#show running-config dhcp
!
ip vrf vrf_dhcp
ip dhcp relay information option remote-id hostname
ip dhcp relay address 192.168.1.2
interface xe5
ip dhcp relay
!
interface xe4
ip dhcp relay uplink
!
 
#show ip dhcp relay
DHCP relay service is Enabled.
VRF Name: vrf_dhcp
Option 82: Enabled
Remote Id: OcNOS
DHCP Servers configured: 192.168.1.2
Interface Uplink/Downlink
--------- -------------
xe5 Downlink
xe4 Uplink
Client
#show ip interface brief | include xe5
xe5 *10.10.20.10 up up
 
Packet captured at DHCP Server
 
Bootstrap Protocol (Discover)
Message type: Boot Request (1)
Hardware type: Ethernet (0x01)
Hardware address length: 6
Hops: 1
Transaction ID: 0x4e61176c
Seconds elapsed: 0
Bootp flags: 0x0000 (Unicast)
0... .... .... .... = Broadcast flag: Unicast
.000 0000 0000 0000 = Reserved flags: 0x0000
Client IP address: 0.0.0.0 (0.0.0.0)
Your (client) IP address: 0.0.0.0 (0.0.0.0)
Next server IP address: 0.0.0.0 (0.0.0.0)
Relay agent IP address: 10.10.20.2 (10.10.20.2)
Client MAC address: b8:6a:97:35:d7:9d (b8:6a:97:35:d7:9d)
Client hardware address padding: 00000000000000000000
Server host name not given
Boot file name not given
Magic cookie: DHCP
Option: (53) DHCP Message Type (Discover)
Length: 1
DHCP: Discover (1)
Option: (55) Parameter Request List
Length: 3
Parameter Request List Item: (1) Subnet Mask
Parameter Request List Item: (28) Broadcast Address
Parameter Request List Item: (3) Router
Option: (60) Vendor class identifier
Length: 39
Vendor class identifier: onie_vendor:x86_64-accton_as7326_56x-r0
Option: (82) Agent Information Option
Length: 12
Option 82 Suboption: (1) Agent Circuit ID
Length: 3
Agent Circuit ID: 786535
Option 82 Suboption: (2) Agent Remote ID
Length: 5
Agent Remote ID: 4f634e4f53
Option: (255) End
Option End: 255
Padding
 
Sample DHCP configuration for using Remote-id
 
class "remote-id" {
match if option agent.remote-id = OcNOS
} # remote-id
 
subnet 10.10.20.0 netmask 255.255.255.0 {
pool {
allow members of "remote-id";
default-lease-time 600;
max-lease-time 7200;
range 10.10.20.3 10.10.10.100;
option routers 10.10.20.2;
option broadcast-address 10.10.20.255;
option subnet-mask 255.255.255.0;
option domain-name-servers 4.2.2.2;
}
VLAN Interface Configuration
Topology
Figure 6-11: DHCP 82 vlan topology
Here, the DHCP Server is running with IP 192.168.1.2 with another pool of subnets 10.10.20.0 configured in the server. Configure a static route to 10.10.20.0 network for DHCP OFFER packets to reach the Relay Agent. In the above topology, vlan 20 is part of interface xe5 in relay Agent and xe5 in Client.
Relay Agent
t
#configure terminal
Enter configure mode.
(config)#ip dhcp relay
Enable DHCP Relay
(config)#ip dhcp relay information option remote-id hostname
Enable DHCP Relay information option with both agent circuit id which is sub option 1 of option 82 and remote-id which is sub option 2 of option 82. String support is also provided for remote-id.
(config)#ip dhcp relay address 192.168.1.2
Configure DHCP relay address
(config)#bridge 1 protocol rstp vlan-bridge
Configure bridge
(config)#vlan 2-100 bridge 1 state enable
Enable some VLANs
(config)#interface xe5
Enter interface mode
(config-if)#switchport
Configure switchport
(config-if)#bridge-group 1
Configure bridge-group
(config-if)#switchport mode hybrid
Configure switchport mode
(config-if)#switchport hybrid allowed vlan all
Enable vlan
(config-if)#exit
Exit from interface mode
(config)#commit
 
 
Commit the candidate configuration to the running configuration
(config)#interface vlan1.20
Enter interface mode for the vlan interface towards client.
(config-if)#ip address 10.10.20.2/24
Add IP address
(config-if)#ip dhcp relay
Configure DHCP relay on the vlan interface connecting to client.
(config-if)#exit
Exit from interface mode
(config)#commit
 
 
Commit the candidate configuration to the running configuration
(config)#interface xe4
Enter interface mode
(config-if)#ip dhcp relay uplink
Configure DHCP relay uplink for the interface connecting to server.
(config-if)#ip address 192.168.1.4/24
Add IP address
(config-if)#exit
Exit interface mode.
(config)#commit
 
 
Commit the candidate configuration to the running configuration
Client
 
#configure terminal
Enter configure mode.
(config)#bridge 1 protocol rstp vlan-bridge
Configure bridge
(config)#vlan 2-100 bridge 1 state enable
Enable VLANs
(config)#interface xe5
Enter interface mode.
(config-if)#switchport
Configure switchport
(config-if)#bridge-group 1
Configure bridge-group
(config-if)#switchport mode hybrid
Configure switchport mode
(config-if)#switchport hybrid allowed vlan add 20 egress-tagged enable
Enable vlan
(config-if)#exit
Exit from interface mode
(config)#commit
 
 
Commit the candidate configuration to the running configuration
(config)#interface vlan1.20
Enter interface mode for the vlan interface which connects relay.
(config-if)#ip address dhcp
Configure IP address DHCP
(config-if)#exit
Exit from interface mode
(config)#commit
 
 
Commit the candidate configuration to the running configuration
Validation
Relay Agent
#show running-config dhcp
!
ip dhcp relay information option remote-id hostname
ip dhcp relay address 192.168.1.2
!
interface vlan1.20
ip dhcp relay
!
interface xe4
ip dhcp relay uplink
!
 
 
#show ip dhcp relay
DHCP relay service is Enabled.
VRF Name: default
Option 82: Enabled
Remote Id: ocnos
DHCP Servers configured: 192.168.1.2
Interface Uplink/Downlink
--------- -------------
Vlan1.20 Downlink
xe4 Uplink
 
Client
#show ip interface brief |include vlan1.20
vlan1.20 *10.10.20.10 up up
 
Packet captured at DHCP Server
 
Bootstrap Protocol (Discover)
Message type: Boot Request (1)
Hardware type: Ethernet (0x01)
Hardware address length: 6
Hops: 1
Transaction ID: 0x59591459
Seconds elapsed: 0
Bootp flags: 0x0000 (Unicast)
0... .... .... .... = Broadcast flag: Unicast
.000 0000 0000 0000 = Reserved flags: 0x0000
Client IP address: 0.0.0.0 (0.0.0.0)
Your (client) IP address: 0.0.0.0 (0.0.0.0)
Next server IP address: 0.0.0.0 (0.0.0.0)
Relay agent IP address: 10.10.20.2 (10.10.20.2)
Client MAC address: b8:6a:97:35:d7:9d (b8:6a:97:35:d7:9d)
Client hardware address padding: 00000000000000000000
Server host name not given
Boot file name not given
Magic cookie: DHCP
Option: (53) DHCP Message Type (Discover)
Length: 1
DHCP: Discover (1)
Option: (55) Parameter Request List
Length: 3
Parameter Request List Item: (1) Subnet Mask
Parameter Request List Item: (28) Broadcast Address
Parameter Request List Item: (3) Router
Option: (60) Vendor class identifier
Length: 39
Vendor class identifier: onie_vendor:x86_64-accton_as7326_56x-r0
Option: (82) Agent Information Option
Length: 17
Option 82 Suboption: (1) Agent Circuit ID
Length: 8
Agent Circuit ID: 766c616e312e3230
Option 82 Suboption: (2) Agent Remote ID
Length: 5
Agent Remote ID: 4f634e4f53
 
Option: (255) End
Option End: 255
Last modified date: 10/19/2023