Step 4: Monitor Statistics for a T3 Interface

Action

To monitor statistics for a T3 interface, use the following JUNOS CLI operational mode command:

user@host> monitor interface t3-fpc/pic/port

Sample Output

user@host> monitor interface t3-1/0/0

router                       Seconds: 78                  Time: 21:44:15

Interface: t3-1/0/0, Enabled, Link is Down

Encapsulation: Cisco-HDLC, Keepalives, Speed: T3

Traffic statistics:                              Current Delta

  Input bytes:              0 (0 bps)                      [0]

  Output bytes:           207 (184 bps)                  [184]

  Input packets:            0 (0 pps)                      [0]

  Output packets:           9 (1 pps)                      [8]

Encapsulation statistics:

  Input keepalives:         0                              [0]

  Output keepalives:        9                              [8]

Error statistics:

  Input errors:             0                              [0]

  Input drops:              0                              [0]

  Input framing errors:     9                              [8]

  CCV                       0                              [0]

Interface warnings:

  o Received keepalive count is zero

  o Framing errors, check FCS, scrambling and subrate configuration

Next='n', Quit='q' or ESC, Freeze='f', Thaw='t', Clear='c', Interface='i'

What It Means

This command checks for and displays common interface failures, indicates whether loopback is detected, and reports any increases in framing errors. Use the information from this command to narrow down possible causes of an interface problem.

NOTE: If you are accessing the router from the console connection, make sure you set the CLI terminal type using the set cli terminal command.

Table 14 presents problem situations and actions to help you further understand the problem.

Table 14: Problem Situations and Actions

Problem Situation	Action
Framing errors are increasing.	Check the frame check sequence (FCS), scrambling, and subrate configuration.
Framing errors are increasing, and the configuration is correct.	Check the cabling to the router and have the carrier verify the integrity of the line.
Input errors are increasing.	Check the cabling to the router and have the carrier verify the integrity of the line.

NOTE: We recommend that you use this command only for troubleshooting purposes. Do not leave it on during normal router operations because real-time monitoring of traffic consumes additional CPU and memory resources.