[root@localhost vpplb]# vppctl show version verbose
Version: v19.01.3-rc0~7-g822dadf
Compiled by: root
Compile host: localhost.localdomain
Compile date: Tue Jun 25 02:18:52 CST 2019
Compile location: /root/vpp_master
Compiler: GCC 7.3.1 20180303 (Red Hat 7.3.1-5)
Current PID: 66904

[root@localhost vpplb]# vppctl show interface
Name Idx State MTU (L3/IP4/IP6/MPLS) Counter Count
GigabitEthernet2/3/0 1 down 9000/0/0/0
GigabitEthernet2/9/0 2 down 9000/0/0/0
GigabitEthernet2/a/0 3 down 9000/0/0/0
local0 0 down 0/0/0/0
[root@localhost vpplb]#

 I have enabled two interfaces as dhcp client

vppctl set interface state GigabitEthernet2/3/0 up
vppctl set interface state GigabitEthernet2/9/0 up
vppctl set dhcp client intfc GigabitEthernet2/3/0
vppctl set dhcp client intfc GigabitEthernet2/9/0

There is only one dhcp_server

1st step, connect the 2/3/0 to dhcp_server, the vpp works normally

[root@localhost vpplb]# vppctl show hardware-interfaces brief
Name Idx Link Hardware
GigabitEthernet2/3/0 1 up GigabitEthernet2/3/0
Link speed: 1 Gbps
GigabitEthernet2/9/0 2 down GigabitEthernet2/9/0
Link speed: unknown
GigabitEthernet2/a/0 3 down GigabitEthernet2/a/0
Link speed: 1 Gbps
local0 0 down local0
Link speed: unknown

[root@localhost vpplb]# vppctl show dhcp client
[0] GigabitEthernet2/3/0 state DHCP_BOUND addr 192.168.243.133/24 gw 192.168.243.2
[1] GigabitEthernet2/9/0 state DHCP_DISCOVER no address

[root@localhost vpplb]# vppctl show interface addr
GigabitEthernet2/3/0 (up):
L3 192.168.243.133/24
GigabitEthernet2/9/0 (up):
GigabitEthernet2/a/0 (dn):
local0 (dn):

The next step, plug out the cable from 2/3/0, and connect 2/9/0 to the dhcp_server

[root@localhost vpplb]# vppctl show hardware-interfaces brief
Name Idx Link Hardware
GigabitEthernet2/3/0 1 down GigabitEthernet2/3/0
Link speed: unknown
GigabitEthernet2/9/0 2 up GigabitEthernet2/9/0
Link speed: 1 Gbps
GigabitEthernet2/a/0 3 down GigabitEthernet2/a/0
Link speed: 1 Gbps
local0 0 down local0
Link speed: unknown
[root@localhost vpplb]# vppctl show dhcp client
[0] GigabitEthernet2/3/0 state DHCP_BOUND addr 192.168.243.133/24 gw 192.168.243.2
[1] GigabitEthernet2/9/0 state DHCP_BOUND addr 192.168.243.133/24 gw 192.168.243.2
[root@localhost vpplb]# vppctl show interface addr
GigabitEthernet2/3/0 (up):
L3 192.168.243.133/24
GigabitEthernet2/9/0 (up):
GigabitEthernet2/a/0 (dn):
local0 (dn):

The interface 2/9/0 cannot get interface ip.