the back side interfaces of AR2240 are not accepting ip address

Hello Dear

AR2240 router is connected to two core switches on GigabitEthernet0/0/0  andGigabitEthernet0/0/1  

  I want to CAR test (To test the rate limit on an inbound interface.)

but the back interfaces are not accepting ip address 

 GigabitEthernet0/0/0  andGigabitEthernet0/0/1 ready have an IP address configured on them, in order to test CAR I need two interfaces that accept IP address, what shall I do to compete CAR test on this router?

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when I remove the fiber cable connection and change the combo-port to copper and use network cable    /

the inteface are not changed to  up state  in PHY and protocol  on GigabitEthernet0/0/0  andGigabitEthernet0/0/1                        /

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for e.g GigabitEthernet4/0/0  and GigabitEthernet4/0/1 are  not accepting IP address 

in order to test the CAR test, I need to interfaces and  GigabitEthernet0/0/0  andGigabitEthernet0/0/1  are already

connected to the core switch and they are as combo-port fiber.

so how can I Test the CAR test on AR 224O?

[KIP-8# AR-2240-GR01]display interface brief

PHY: Physical

*down: administratively down

(l): loopback

(s): spoofing

(b): BFD down

^down: standby

(e): ETHOAM down

(v): VirtualPort

InUti/OutUti: input utility/output utility

Interface                   PHY   Protocol  InUti OutUti   inErrors  outErrors

Cellular0/0/0               down  down         0%     0%          0          0

Cellular0/0/1               down  down         0%     0%          0          0

Cellular3/0/0               down  down         0%     0%          0          0

GigabitEthernet0/0/0        up    up        0.01%  0.01%          0          0

GigabitEthernet0/0/1        up    up        0.01%     0%          0          0

GigabitEthernet0/0/2        down  down         0%     0%          0          0

GigabitEthernet0/0/3(v)     up    down         0%     0%          0          0

GigabitEthernet4/0/0        down  down         0%     0%          0          0

GigabitEthernet4/0/1        down  down         0%     0%          0          0

GigabitEthernet4/0/2        up    up        0.01%  0.01%          0          0

GigabitEthernet4/0/3        down  down         0%     0%          0          0

GigabitEthernet6/0/0        down  down         0%     0%          0          0

GigabitEthernet6/0/1        down  down         0%     0%          0          0