Running ATM Ping

Keep in mind the following when you use ATM ping:

• Before you can run ATM ping, you need to add a PVC for the VPI and VCI over which you run the ping.
• Because ATM ping requires the receipt of OAM cells, make sure that the receipt and transmission of OAM cells is not disabled (using the atm oam flush command). To reenable the receipt and transmission of OAM cells, enter no atm oam flush.
• Disabling receipt of OAM cells during a ping operation stops all outstanding ping operations. You need to manually restart the ping operation after receipt of OAM cells for the interface is enabled.
• Because ATM ping is a dynamic (on-demand) operation, none of the configuration related to ATM ping is saved. To avoid acquiring excessive bandwidth for OAM, the number of outstanding ping operations on each interface is limited to 12.

ping atm interface atm

• Use to send loopback cells from an ATM interface or circuit.
• The VPI and VCI fields determine the type of loopback cells used for the ping operation. By default F5 end-to-end loopback OAM cells are used.
  • To send F4 segment loopback cells, set the VCI to 3.
  • To send F4 end-to-end loopback cells, set the VCI to 4.
• Use the end-loopback keyword to send the ping to the connection endpoint.
• Use the seg-loopback keyword to send the ping to the first segment point (for example, the next neighbor switch).
• Use the destination option to specify the value of the location ID included in the loopback cell. The location ID is a 16-octet field, and the destination portion is 4 octets. You can set the location ID to a specific destination or to 0s (zeros) or 1s (ones).
  • If you set the destination to 0, the loopback location ID in the loopback cell is initialized to all 0s, and each segment point in the network responds to the ping.
  • If you set the destination to 1s, the loopback location ID in the loopback cell is initialized to all 1s, and only the connection endpoint responds to the ping.
  • If you use the default value of 0xFFFFFFFF, the loopback location ID in the loopback cell is initialized to all 1s.

  For information about how the router handles loopback cells based on location ID, see Table 7.

• The count keyword sets the number of OAM loopback cells to send to the destination. The default value is 5. The maximum is 32.
• The timeout keyword sets the amount of time to wait for a response to the sent OAM loopback cell. The default value is 5 seconds.
• The following characters can appear in the display after the ping command has been issued:
  • !—Each exclamation point indicates that a reply was received
  • .—Each period indicates that the ping timed out while waiting for a reply
• Example 1—This example generates end-to-end loopback cells for VPI=0 and VCI=105 on ATM interface 2/0. The count value is 5 OAM loopback cells, and the timeout value is 2 seconds.

  host1#ping atm interface atm 2/0 0 105 end-loopback count 5 timeout 2

  Sending 5 53-byte OAM end-to-end loopback Echoes timeout is 2 secs

  Press Ctrl+c to stop

  !!!!!

  Success rate = 100% (5/5), round-trip min/avg/max = 0/4/10 ms

• Example 2—This example generates segment loopback cells for VPI=0 and VCI=105 on ATM interface 2/0. The destination is set to 0xFFFFFFFF, the count value is 3 OAM loopback cells, and the timeout value is 1 second.

  host1#ping atm interface atm 2/0 0 105 seg-loopback 0xFFFFFFFF count 3 timeout 1

  Sending 3 53-byte OAM segment loopback Echoes timeout is 1 secs

  Press Ctrl+c to stop

  !!!

  Success rate = 100% (3/3), round-trip min/avg/max = 0/3/10 ms

• There is no no version.
• See ping atm interface atm.

Copyright © 2008, Juniper Networks, Inc. All rights reserved. Trademark Notice.