[j-nsp] J4300 MTU question

[Herman Ng]

Hi,
Another question on changing J4300 MTU size:

As show below, on the e1 interface, the Media MTU is 1504 and the Protocol
MTU is 1500.
But when try to change the Media MTU to 2000: *set interfaces e1-1/0/0 mtu
2000, and commit.*
It give *Family MTU is too large relative to device MTU*

What is this error mean, and how to fix it?

Any help would be appreciated.
Thanks
Herman

root at GPA-BG-JR1> show interfaces e1-1/0/0
  Interface index: 139, SNMP ifIndex: 60
  Link-level type: PPP, *MTU: 1504*, Clocking: Internal, Speed: 128kbps,
  Loopback: None, FCS: 16, Framing: G704
  Device flags   : Present Running
  Interface flags: Point-To-Point SNMP-Traps 16384
  Link flags     : Keepalives
  Keepalive settings: Interval 10 seconds, Up-count 1, Down-count 3
  Keepalive: Input: 111526 (00:00:08 ago), Output: 249826 (00:00:05 ago)
  LCP state: Opened
  NCP state: inet: Opened, inet6: Not-configured, iso: Not-configured, mpls:
  Not-configured
  CHAP state: Not-configured
  CoS queues     : 8 supported
  Last flapped   : 2006-05-10 15:53:18 GST (9w2d 22:00 ago)
  Input rate     : 232 bps (0 pps)
  Output rate    : 176 bps (0 pps)
  DS1   alarms   : None
  DS1   defects  : None

  Logical interface e1-1/0/0.0 (Index 69) (SNMP ifIndex 62)
    Flags: Point-To-Point SNMP-Traps Encapsulation: PPP
    Protocol inet, *MTU: 1500*
      Flags: None
      Addresses, Flags: Is-Preferred Is-Primary
        Destination: 194.170.102.0/30, Local: 194.170.102.2,
        Broadcast: 194.170.102.3

root at GPA-BG-JR1>

root at GPA-BG-JR1# *set interfaces e1-1/0/0 mtu 2000*
Jul 15 13:51:14  GPA-BG-JR1 mgd[10045]: UI_CFG_AUDIT_SET: User 'root' set:
[interfaces e1-1/0/0 mtu] <unconfigured> -> "2000"
Jul 15 13:51:14  GPA-BG-JR1 mgd[10045]: UI_CMDLINE_READ_LINE: User 'root',
command 'set interfaces e1-1/0/0 mtu 2000 ' [edit]
root at GPA-BG-JR1# commit
Jul 15 13:52:03  GPA-BG-JR1 mgd[10045]: UI_CMDLINE_READ_LINE: User 'root',
command 'commit '
Jul 15 13:52:03  GPA-BG-JR1 mgd[10045]: UI_COMMIT: User 'root' performed
commit: no comment
Jul 15 13:52:03  GPA-BG-JR1 mgd[10045]: UI_COMMIT_PROGRESS: commit:
exporting juniper.conf
Jul 15 13:52:03  GPA-BG-JR1 mgd[10045]: UI_COMMIT_PROGRESS: commit:
expanding groups
Jul 15 13:52:03  GPA-BG-JR1 mgd[10045]: UI_COMMIT_PROGRESS: commit: finished
expanding groups [edit interfaces e1-1/0/0 unit 0 family]
*  'inet'
     Family MTU is too large relative to device MTU
*