Technical Documentation

Configuring Helpers (NSM Procedure)

You can enable Trivial File Transfer Protocol (TFTP) or Domain Name System (DNS) request packet forwarding, or configure the router or interface to act as a Dynamic Host Configuration Protocol (DHCP) or Bootstrap Protocol (BOOTP) relay agent. You use only one server address per interface or global configuration. See the following topics:

Configuring a Router or Interface to Act as a Bootstrap Protocol Relay Agent

You can configure a router or interface to act as a Dynamic Host Configuration Protocol (DHCP) or bootstrap protocol (BOOTP) relay agent using this option.

To configure a BOOTP relay agent in NSM:

  1. In the NSM navigation tree, select Device Manager > Devices.
  2. Click the Device Tree tab, and then double-click the device to select it.
  3. Click the Configuration tab. In the configuration tree, expand Forwarding Options > Helpers > BOOTP.
  4. Add or modify settings as specified in Table 1.
  5. Click one:
    • OK—Saves the changes.
    • Cancel—Cancels the modifications.

Table 1: BOOTP Configuration Details

Task Your Action

Configures a router or interface to act as a DHCP or BOOTP relay agent.

  1. In the Comment box, enter the comment.
  2. Select the Relay Agent check box to configure router as a BOOTP relay agent.
  3. From the Maximum Hop Count list, select the maximum number of hops allowed.

    Default: 4 hops

  4. From the Minimum Wait Time list, select the minimum time allowed.

    Default: 3 seconds

  5. From the Client Response Ttl list, select the IIP time-to-live (TTL) value in DHCP response packets sent to a DHCP client.

Configure DHCP option 82.
  1. Click Dhcp Option82 next to Bootp.
  2. In the Comment box, enter the comment.
  3. Select the Disable check box to disable DHCP option 82 on this VLAN.
  4. Click Circuit Id next to Dhcp Option82.
  5. In the Comment box, enter the comment.
  6. From the Prefix list, select the prefix
    • hostname—Set hostname as the prefix.
  7. Select the Use Interface Description check box to use interface description instead of name.
  8. Select the Use Vlan Id check box to use vlan id.
  9. Click Remote Id next to Dhcp Option82.
  10. In the Comment box, enter the comment.
  11. From the Prefix list, select the prefix
    • none—Set no prefix.
    • hostname—Set hostname as the prefix.
    • mac—Set chassis MAC as the prefix.
  12. Select the Use Interface Description check box to use interface description instead of name.
  13. In the Use String check box, enter the raw string instead of the default remote ID.
  14. Click Vendor Id next to Dhcp Option82.
  15. In the Comment box, enter the comment.
  16. In the Use String check box, enter the raw string instead of the default remote ID.

Specify the interface for a DHCP and BOOTP relay agent.

  1. Click Interface next to BOOTP.
  2. Click Add new entry next to Interface.
  3. Expand Interface.
  4. In the Name box, enter the interface for a DHCP and BOOTP relay agent.
  5. In the Comment box, enter the comment.
  6. Select the No Listen check box to disable recognition of DNS requests or stop packets from being forwarded on a logical interface, a group of logical interfaces, or a router.
  7. Select the Broadcast check box to issue the DHCP or BOOTP request as a broadcast message.
  8. In the Descriptions box, enter the description of BOOTP, DHCP, Domain Name System (DNS), or Trivial File Transfer Protocol (TFTP) service, or of an interface that is configured for the service.
  9. From the Maximum Hop Count list, select the maximum number of hops allowed.

    Default: 4 hops

  10. From the Minimum Wait Time list, select the minimum time allowed.

    Default: 3 seconds

  11. From the Client Response Ttl list, select the IIP time-to-live (TTL) value in DHCP response packets sent to a DHCP client.

Configure the router to act as a DHCP and BOOTP relay agent.

  1. Click Server next to Interface.
  2. Click Add new entry next to Server.
  3. Expand Server.
  4. In the Name box, enter the server identifier.
  5. In the Comment box, enter the comment.
  6. Click Logical System next to Server.
  7. Click Add new entry next to Logical System.
  8. Expand logical-system.
  9. In the Name box, enter the logical system name.
  10. In the Comment box, enter the comment.
  11. Click Routing Instance next to logical-system.
  12. Click Add new entry next to Routing Instance.
  13. In the New routing-instance window, enter the routing instance name.
  14. Click Routing Instance next to server.
  15. Click Add new entry next to Routing Instance.
  16. In the New routing-instance window, enter the routing instance name.
  17. Click Server next to BOOTP.
  18. Click Add new entry next to Server.
  19. Expand Server.
  20. Click Logical System next to Server.
  21. Click Add new entry next to Logical System.
  22. In the Name box, enter the logical system name.
  23. In the Comment box, enter the comment.
  24. Click Routing Instance next to logical-system.
  25. Click Add new entry next to Routing Instance.
  26. In the New routing-instance window, enter the routing instance name.
  27. Click Routing Instance next to server.
  28. Click Add new entry next to Routing Instance.
  29. In the New routing-instance window, enter the routing instance name.

Enabling DNS Request Packet Forwarding

You can configure the router to support Domain Name System (DNS) and Trivial File Transfer Protocol (TFTP) packet forwarding for IPv4 traffic, which allows clients to send DNS or TFTP requests to the router. The responding DNS or TFTP server recognizes the client address and sends a response directly to that address. By default, the router ignores DNS and TFTP request packets.

To enable DNS request packet forwarding in NSM:

  1. In the NSM navigation tree, select Device Manager > Devices.
  2. Click the Device Tree tab, and then double-click the device to select it.
  3. Click the Configuration tab. In the configuration tree, expand Forwarding Options > Helpers > Domain.

    Note: For configuring TFTP, expand Forwarding Options > Helpers > TFTP.

  4. Add or modify settings as specified in Table 2.
  5. Click one:
    • OK—Saves the changes.
    • Cancel—Cancels the modifications.

Table 2: DNS and TFTP Configuration Details

Task Your Action

Specify the interface for monitoring and forwarding DNS or TFTP requests.

  1. In the Comment box, enter the comment.
  2. In the Description box, enter the description of BOOTP, DHCP, Domain Name System (DNS), or Trivial File Transfer Protocol (TFTP) service, or of an interface that is configured for the service.
  3. Click Interface next to Domain.
  4. Click Add new entry next to Interface.
  5. Expand Interface.
  6. In the Name box, enter the interface for a DHCP and BOOTP relay agent.
  7. In the Comment box, enter the comment.
  8. Select the No Listen check box to disable recognition of DNS requests or stop packets from being forwarded on a logical interface, a group of logical interfaces, or a router.
  9. Select the Broadcast check box to issue the DHCP or BOOTP request as a broadcast message.
  10. In the Descriptions box, enter the description of BOOTP, DHCP, Domain Name System (DNS), or Trivial File Transfer Protocol (TFTP) service, or of an interface that is configured for the service.
  11. Click Server next to Interface.
  12. In the Comment box, enter the comment.
  13. In the Address box, enter the address of the server.
  14. Expand Server.
  15. Click Logical System next to Server.
  16. Select logical-system or routing-instance.
  17. Click Server next to Domain.
  18. In the Comment box, enter the comment.
  19. In the Address box, enter the address of the server.
  20. Expand Server.
  21. Click Logical System next to Server.
  22. Select logical-system or routing-instance.

Configuring a Port for a DHCP or BOOTP Relay Agent

You can a configure port for a DHCP or BOOTP relay agent using this option.

To configure port for a DHCP or BOOTP relay agent in NSM:

  1. In the NSM navigation tree, select Device Manager > Devices.
  2. Click the Device Tree tab, and then double-click the device to select it.
  3. Click the Configuration tab. In the configuration tree, expand Forwarding Options > Helpers.
  4. Select Port.
  5. Add or modify settings as specified in Table 3.
  6. Click one:
    • OK—Saves the changes.
    • Cancel—Cancels the modifications.

Table 3: Port Configuration Details

Task Your Action

Configuring a Port.
  1. From the Name list, select the port number.
  2. In the Comment box, enter the comment.
  3. In the Description box, enter the description of BOOTP, DHCP, Domain Name System (DNS), or Trivial File Transfer Protocol (TFTP) service, or of an interface that is configured for the service.
  4. Expand Port.
  5. Click Interface next to Domain.
  6. Click Add new entry next to Interface.
  7. Expand Interface.
  8. In the Name box, enter the interface for a DHCP and BOOTP relay agent.
  9. In the Comment box, enter the comment.
  10. Select the No Listen check box to disable recognition of DNS requests or stop packets from being forwarded on a logical interface, a group of logical interfaces, or a router.
  11. Select the Broadcast check box to issue the DHCP or BOOTP request as a broadcast message.
  12. In the Descriptions box, enter the description of BOOTP, DHCP, Domain Name System (DNS), or Trivial File Transfer Protocol (TFTP) service, or of an interface that is configured for the service.
  13. Click Server next to Interface.
  14. Expand Server.
  15. In the Comment box, enter the comment.
  16. In the Address box, enter the address of the server.
  17. Click Logical System next to Server.
  18. Select the corresponding logical system.
  19. Click Server next to Port.
  20. In the Comment box, enter the comment.
  21. In the Address box, enter the address of the server.
  22. Click Logical System next to Server.
  23. Select the corresponding logical system.

Configuring Tracing Operations for BOOTP, DNS, and TFTP Packet Forwarding

You can configure tracing operations for BOOTP, DNS, and TFTP packet forwarding using this option. BOOTP, DNS, and TFTP forwarding tracing operations track all BOOTP, DNS, and TFTP operations and record them in a log file. The logged error descriptions provide detailed information to help you solve problems faster.

To configure tracing operations in NSM:

  1. In the NSM navigation tree, select Device Manager > Devices.
  2. Click the Device Tree tab, and then double-click the device to select it.
  3. Click the Configuration tab. In the configuration tree, expand Forwarding Options > Helpers > TFTP.
  4. Select Traceoptions.
  5. Add or modify settings as specified in Table 4.
  6. Click one:
    • OK—Saves the changes.
    • Cancel—Cancels the modifications.

Table 4: Traceoptions Configuration Details

Task Your Action

Define tracing operations for event policy.
  1. In the Comment box, enter the comment for the traceoptions.
  2. Select the No Remote Trace check box to disable remote tracing globally or for a specific tracing operation.
  3. From the Level list, select the level.

Specify the name of the file to receive the output of the tracing operation and the maximum number of trace files.

  1. In the Comment box, enter the comment for the file.
  2. In the Filename box, enter the name of the file to receive the output of the tracing operation.
  3. In the Size box, enter the maximum size of each trace file, in kilobytes (KB), megabytes (MB), or gigabytes (GB).
  4. From the Files list, select the maximum number of trace files.

    Range: 2 through 1000.

    Default: 3

  5. Select one of the following:
    • world-readable—To enable unrestricted file access
    • no-world-readable—To restrict file access to owner. This is the default setting.
  7. In the Matchbox, enter the regular expression.

Specify the tracing operation to perform

  1. Click Add new entry next to Flag.
  2. From the Name list, select the flag.
  3. In the Comment box, enter the comment for the flag.

Published: 2009-08-23