Monitoring Interface Rate Statistics for VLAN Subinterfaces

Purpose

Display bit rate and packet rate statistics over a specified time interval for one or more VLAN subinterfaces configured on the router.

Action

To display interface rate statistics for VLAN subinterfaces:

  1. Log in to the router by using a local console session or a virtual terminal (vty) session (such as a Telnet session).

    While you are using the monitor vlan interface command, you must keep the console or terminal session open and you cannot issue any other commands at the session during this time.

    For information about logging in to the router, see Accessing the CLI in JunosE System Basics Configuration Guide.

  2. Access User Exec mode or Privileged Exec mode.

    For information, see Accessing Command Modes in JunosE System Basics Configuration Guide.

  3. Specify the interface identifier for each VLAN subinterface that you want to monitor.
    host1#monitor vlan interface fastEthernet 0/0.1 fastEthernet 4/0.1 display-time-of-day

    For information about specifying interface identifiers for VLAN subinterfaces configured over Ethernet interfaces, see VLAN Overview. For information about specifying interface identifiers for VLAN subinterfaces configured over LAG bundles, see Configuring 802.3ad Link Aggregation.

    By default, the router uses a 5-second time interval between polls to calculate bit rates and packet rates for each specified VLAN subinterface. Optionally, you can use the load-interval keyword to specify a nondefault time interval in the range 5–30 seconds.

    You can also include the optional display-time-of-day keyword to show the time of day at which the router gathers bit rate and packet rate statistics for each interval. Displaying the time of day enables you to monitor when a particular VLAN subinterface is underutilized or overutilized.

  4. Review the command output.
    host1#monitor vlan interface fastEthernet 0/0.1 fastEthernet 4/0.1 
    display-time-of-day
                            Seconds
                            between                                     Time
           Interface         polls    Input bps/pps   Output bps/pps   (UTC)
    ----------------------- -------- --------------- --------------- --------
    FastEthernet 0/0.1             0           --/--           --/-- 10:50:07
    FastEthernet 4/0.1             0           --/--           --/-- 10:50:07
    FastEthernet 0/0.1             5      120240/100      120240/100 10:50:12
    FastEthernet 4/0.1             5      120000/100      120000/100 10:50:12
    FastEthernet 0/0.1             5      120240/100      120240/100 10:50:17
    FastEthernet 4/0.1             5      120000/100      120000/100 10:50:17

    The router polls each VLAN subinterface at the specified load interval (the default 5-second interval in this example) to calculate and display bit rate and packet rate statistics. The first line of output for each interface always displays 0 (zero) for the number of seconds between polls, and dashes (--/--) in the Input bps/pps and Output bps/pps columns. These values indicate that the router initially takes a baseline for each interface against which to measure subsequent statistics. The router continues to display subsequent lines of output for each interface at the specified load interval until you press Ctrl+c to stop the command.

    For a description of each field in the monitor vlan interface command output, see Table 11.

  5. When you are finished, press Ctrl+c to stop the monitor vlan interface command.
    host1#^C

To display bit rate and packet rate statistics over the default (5-second) load interval for a single VLAN subinterface:

host1#monitor vlan interface fastEthernet 0/0.1
                        Seconds
                        between
       Interface         polls    Input bps/pps   Output bps/pps
----------------------- -------- --------------- ---------------
FastEthernet 0/0.1             0           --/--           --/--
FastEthernet 0/0.1             5      120240/100      120240/100
FastEthernet 0/0.1             5      120000/100      120000/100
FastEthernet 0/0.1             5        92400/77        92400/77
FastEthernet 0/0.1             5        88800/74        88800/74
FastEthernet 0/0.1             5      120000/100      120000/100
host1#^C

To display bit rate and packet rate statistics over a 10-second load interval for two VLAN subinterfaces, with the time of day that the statistics were calculated:

host1#monitor vlan interface fastEthernet 0/0.1 fastEthernet 4/0.1 
load-interval 10 display-time-of-day
                        Seconds
                        between                                     Time
       Interface         polls    Input bps/pps   Output bps/pps   (UTC)
----------------------- -------- --------------- --------------- --------
FastEthernet 0/0.1             0           --/--           --/-- 10:50:33
FastEthernet 4/0.1             0           --/--           --/-- 10:50:33
FastEthernet 0/0.1            10      120120/100      120120/100 10:50:43
FastEthernet 4/0.1            10      120000/100      120000/100 10:50:43
FastEthernet 0/0.1            10      120000/100      120000/100 10:50:53
FastEthernet 4/0.1            10      120000/100      120000/100 10:50:53
host1#^C

Meaning

Table 11 lists the monitor vlan interface command output fields.

Table 11: monitor vlan interface Output Fields

Field Name

Field Description

Interface

Interface identifier for the Ethernet or LAG interface on which the VLAN subinterface resides

Seconds between polls

Number of seconds at which the router calculates bit rate and packet rate statistics

Input bps/pps

Number of bits per second (bps) and packets per second (pps) received on this interface during the specified load interval

Output bps/pps

Number of bits per second (bps) and packets per second (pps) transmitted on this interface during the specified load interval

Time

Time of day, in hh:mm:ss format, at which the router calculates the bit rate and packet rate statistics for the current intervalS-VLAN Ethertype value, if configured

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