Check the FCS Configuration

Purpose

If you are having problems with a connection, check your router's FCS configuration and, if possible, the FCS configuration on the router on the other side of the connection.

Action

From the JUNOS CLI operational mode, use one of the following two commands to check the SONET frame checksum:

user@host> show configuration interfaces | interface-name

or

user@host> show interfaces interface-name

   
NOTE: The option to display a specific configuration with the show configuration command hierarchy was introduced in JUNOS Release 5.3. 


 

Sample Output 1

user@host> show configuration interfaces so-0/0/0

encapsulation cisco-hdlc;

sonet-options {

    fcs 32;

    payload-scrambler;

}

unit 0 {

    family inet {

        address 9.0.0.2/32 {

            destination 9.0.0.1;

        }

    }

    family mpls;

}

Sample Output 2

user@host> show interfaces so-0/0/1

Physical interface: so-0/0/1, Enabled, Physical link is Up

  Interface index: 48, SNMP ifIndex: 114

  Link-level type: PPP, MTU: 4474, Clocking: Internal, SONET mode, Speed: OC3, 
Loopback: None, FCS: 32,

  Payload scrambler: Disabled

  Device flags   : Present Running

  Interface flags: Point-To-Point SNMP-Traps

  Link flags     : Keepalives

  Keepalive settings: Interval 10 seconds, Up-count 1, Down-count 3

  Keepalive: Input: 70627 (00:00:07 ago), Output: 70791 (00:00:08 ago)

  LCP state: Opened

  NCP state: inet: Opened, inet6: Not-configured, iso: Opened, mpls: 
Not-configured

  Input rate     : 78056456 bps (6504 pps)

  Output rate    : 78044840 bps (6503 pps)

  SONET alarms   : None

  SONET defects  : None

  Logical interface so-0/0/1.0 (Index 61) (SNMP ifIndex 118) 

    Flags: Point-To-Point SNMP-Traps Encapsulation: PPP

    Protocol inet, MTU: 4470, Flags: None

      Addresses, Flags: Is-Preferred Is-Primary

        Destination: 192.168.50.0/30, Local: 192.168.50.1

    Protocol iso, MTU: 4470, Flags: None

What It Means

Sample output 1 shows that FCS 32 is configured. If you use the show configuration or show configuration interfaces command, you must scroll to the particular interface for the FCS configuration status.

What It Means

Sample output 2 shows that FCS 32 is configured. To change the FCS configuration, see Return to the Default 16-Bit Checksum, Configure a 16-Bit Checksum, or Configure a 32-Bit Checksum.