ISR 4331 Duplex and Speed Settings

[tparrettcisco]

Just unpacked a new isr 4331 and working on the config.  I need to set the duplex and speed on both interfaces.  So far I have

interface GigabitEthernet0/0/0
description LAN
ip address 10.1.1.218 255.255.255.0
speed 1000
no negotiation auto

interface GigabitEthernet0/0/1
description WAN
ip address 192.168.200.100 255.255.255.0
ip nat inside
speed 1000
no negotiation auto

When I enter duplex full on either interface, the command is accepted (no errors) but when I do sh run again and look at the interface sections it's not listed. 

When I run sh int g0/0/0 I see

GigabitEthernet0/0/0 is up, line protocol is up
  Hardware is ISR4331-3x1GE, address is 6cdd.3066.d6e0 (bia 6cdd.3066.d6e0)
  Description: LAN
  Internet address is 10.1.1.218/24
  MTU 1500 bytes, BW 1000000 Kbit/sec, DLY 10 usec,
     reliability 255/255, txload 1/255, rxload 1/255
  Encapsulation ARPA, loopback not set
  Keepalive not supported
  Full Duplex, 1000Mbps, link type is force-up, media type is RJ45
  output flow-control is on, input flow-control is on
  ARP type: ARPA, ARP Timeout 04:00:00
  Last input never, output 00:00:11, output hang never
  Last clearing of "show interface" counters never
  Input queue: 0/375/0/0 (size/max/drops/flushes); Total output drops: 0
  Queueing strategy: fifo
  Output queue: 0/40 (size/max)
  5 minute input rate 0 bits/sec, 0 packets/sec
  5 minute output rate 0 bits/sec, 0 packets/sec
     0 packets input, 0 bytes, 0 no buffer
     Received 0 broadcasts (0 IP multicasts)
     0 runts, 0 giants, 0 throttles
     0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
     0 watchdog, 0 multicast, 0 pause input
     1880 packets output, 519026 bytes, 0 underruns
     0 output errors, 0 collisions, 3 interface resets
     0 unknown protocol drops
     0 babbles, 0 late collision, 0 deferred
     9 lost carrier, 0 no carrier, 0 pause output
     0 output buffer failures, 0 output buffers swapped out

So do I have it set correctly?  Will I not see the command listed with the other interface commands? I'm use to working with the older ios where I actually see the command listed within the interfaces.  I'm sure this is easy...what am I missing?

[Reza Sharifi · Accepted solution]

Usually, when you apply a command and don't see it in the running config, that command is turned on by default.

So, most likely the new IOS has full duplex turned on by default.

HTH

[vamikhai]

Half-duplex 1G basically does not exist, thus when you enter speed 1000 - it automatically implies it's full duplex.

[Joseph W. Doherty]

Copper gig switch ports often only support full duplex at gig, as it's assumed anyone running copper gig wouldn't be using or needing gig half duplex.

[Leo Laohoo]

If you want to hard code the speed and duplex settings, keep an eye out for line errors. The counters for "input errors" should start incrementing.

[edward.michels]

I just had this same issue. You have to hard code the media type to rj45 with the interface command 

media-type rj45

and then you get the option to statically set speed and duplex.