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juniper@R1# show interfaces ge-0/0/0 | display set 
set interfaces ge-0/0/0 mtu 9192
set interfaces ge-0/0/0 unit 0 family inet address 12.1.1.1/24

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juniper@R1# commit 
commit complete

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juniper@R1# run show interfaces ge-0/0/0  
Physical interface: ge-0/0/0, Enabled, Physical link is Up
  Interface index: 131, SNMP ifIndex: 121
  Link-level type: Ethernet, MTU: 9192, Link-mode: Full-duplex, Speed: 1000mbps, BPDU Error: None, MAC-REWRITE Error: None, Loopback: Disabled,
  Source filtering: Disabled, Flow control: Enabled, Auto-negotiation: Enabled, Remote fault: Online
  Device flags   : Present Running
  Interface flags: SNMP-Traps Internal: 0x4000
  Link flags     : None
  CoS queues     : 8 supported, 8 maximum usable queues
  Current address: 00:1d:b5:7a:1e:80, Hardware address: 00:1d:b5:7a:1e:80
  Last flapped   : 2011-06-21 07:04:17 UTC (23:03:55 ago)
  Input rate     : 0 bps (0 pps)
  Output rate    : 0 bps (0 pps)
  Active alarms  : None
  Active defects : None

  Logical interface ge-0/0/0.0 (Index 70) (SNMP ifIndex 132) 
    Flags: SNMP-Traps Encapsulation: ENET2
    Input packets : 1 
    Output packets: 3
    Security: Zone: Null
    Protocol inet, MTU: 9178
      Flags: None
      Addresses, Flags: Is-Preferred Is-Primary
        Destination: 12.1.1/24, Local: 12.1.1.1, Broadcast: 12.1.1.255

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juniper@R1#