Configuring VLAN Dynamic Subinterfaces

Figure 59: Dynamic Interface Columns over Dynamic VLAN Subinterfaces

Figure 60: Dynamic IP and PPPoE over Single Dynamic VLAN Subinterface

Figure 61: Dynamic VLAN Subinterfaces for Subscribers

For example, if an S-VLAN is assigned at the DSLAM, and each DSLAM subscriber at the DSLAM is assigned a unique VLAN ID, the JunosE Software dynamically constructs a VLAN-based interface column using that S-VLAN/VLAN ID pair when the subscriber logs in.

For more information about the attributes of VLAN and S-VLAN subinterfaces, see Configuring VLAN and S-VLAN Subinterfaces .

VLAN Base Profiles

To configure a dynamic VLAN subinterface over a static VLAN major interface, you must create a base profile. The base profile includes one or more of the following attributes for the VLAN subinterface:

• advisory-rx-speed—Sets an advisory receive speed for VLAN subinterfaces that are created with this profile. For information, see vlan advisory-rx-speed.
• advisory-tx-speed—Sets an advisory connect speed for VLAN subinterfaces that are created with this profile. For information, see vlan advisory-tx-speed.
• auto-configure—Specifies the types of upper-interface encapsulations that are accepted or detected by the dynamic VLAN subinterface. For information, see vlan auto-configure.
• auto-configure agent-circuit-identifier—Enables the creation of VLAN subinterfaces that are based on agent-circuit-identifier information. For information, see vlan auto-configure agent-circuit-identifier.
• description—Assigns a description to VLAN subinterfaces that are created with this profile. For information, see vlan description.
• policy—Assigns a policy to a VLAN. For information, see vlan policy.
• profile—Adds a nested profile assignment, which references another profile that dynamically configures an upper-interface encapsulation type over the VLAN subinterface. For information, see vlan profile.
• service-profile—Specifies a service profile name for a VLAN. For information, see vlan service-profile.
• svlan ethertype—Specifies that the packet must use this Ethertype to create the dynamic VLAN subinterface. For more information, see svlan ethertype.

You can override the base profile assignment for a VLAN or S-VLAN that exists with a profile. For more information, see Overriding Base Profile Assignments.

Nested Profile Assignments

The configuration for each dynamic upper-interface encapsulation type might differ, depending on the column type built by the router. To manage these differences, you can include one or more nested profile assignments within the VLAN base profile. A nested profile assignment references another profile that configures attributes for a dynamic upper-interface encapsulation type. You can create different profiles for each upper-interface encapsulation type, or you can create a single profile that includes attributes for multiple encapsulation types.

For example, the following commands create a base profile named vlanBaseProfile with two nested profile assignments. The first nested profile assignment references an IP profile named vlanProfileIp, and the second nested profile assignment references a PPPoe profile named vlanProfilePppoe.

In this example, vlanProfileIp and vlanProfilePppoe have different IP configurations depending on the dynamic interface column constructed. For an IP over VLAN dynamic interface column, the router uses the IP attributes in vlanProfileIp. For an IP over PPPoE dynamic interface column, the router uses the IP attributes in vlanProfilePppoe.

For information about creating profiles for upper-interface encapsulation types, see Configuring a Dynamic Interface from a Profile in Configuring Dynamic Interfaces.

Additional Profile Characteristics for Upper Interfaces

In addition to VLAN attributes and nested profile assignments, the base profile for a dynamic VLAN subinterface can also include individual characteristics for several upper-interface encapsulation types, provided that no nested profile assignment for the specified encapsulation type is in the base profile. If, on the other hand, a nested profile assignment for this encapsulation type exists in the base profile, the router obtains all characteristics for that encapsulation type from the nested profile and not from the base profile.

For lists of the characteristics for each supported upper-interface encapsulation type, see Profile Characteristics.

Bulk Configuration of VLAN Ranges

Dynamic creation of VLAN subinterfaces requires you to configure a range of single-tagged VLAN IDs and double-tagged S-VLAN IDs on the VLAN major interface and assign a name to this range. You can also configure a range of S-VLAN IDs that is based on agent-circuit-identifier information. See Bulk Configuration of VLAN Ranges Using Agent-Circuit-Identifier Information for information.

Each VLAN range consists of one or more nonoverlapping VLAN subranges. A VLAN subrange is a group of VLAN IDs and S-VLAN IDs that reside within the VLAN range you specify.

The process of configuring a VLAN range for a dynamic VLAN subinterface is referred to as bulk configuration. You create a bulk configuration by issuing the vlan bulk-config command. For example, the following commands create a VLAN bulk configuration named myBulkConfig on the specified VLAN interface.

In the example, the vlan bulk-config command configures a VLAN range made up of two VLAN subranges. The first subrange configures S-VLANs 101–1100 and VLANs 1–375. The second subrange configures S-VLANs 1300–1500 and VLANs 500–650.

Note: For information about the maximum number of VLAN bulk configurations supported per router and line module, see JunosE Release Notes, Appendix A, System Maximums.

After you issue the vlan bulk-config command, the router provisions all VLAN IDs and S-VLAN IDs in the specified VLAN range at the same time. The router does not dynamically create the VLAN subinterface until it receives incoming data traffic on the VLAN ID or S-VLAN ID.

After you create a named VLAN range, you cannot remove the underlying VLAN major interface until you issue the no vlan bulk-config command to remove the VLAN range from that interface.

Bulk Configuration of VLAN Ranges Using Agent-Circuit-Identifier Information

Using bulk configuration to create S-VLAN IDs based on agent-circuit-identifier information is similar to the process of creating a bulk-configured VLAN range that is not based on agent-circuit-identifier information. However, when you issue the vlan bulk-config command with the svlan-range keyword to specify the S-VLAN ID range, you then specify the agent-circuit-identifier keyword instead of a VLAN ID range. This technique creates a unique type of S-VLAN range in which the agent-circuit-identifier information is used in place of the second tag.

The agent-circuit-identifier string is contained in the option 82 field of DHCP messages for DHCP traffic, or in the DSL Forum VSA 26-1 of PPPoE PADR and PADI packets for PPPoE traffic. The agent-circuit-identifier information identifies the subscriber’s access node and the DSL line on the access node. You can repeat the svlan-range and agent-circuit-identifier keywords to provide nonoverlapping VLAN subranges that reside within the VLAN range.

The following example configures a VLAN ID range made up of two subranges. The first subrange configures S-VLANs 200–250 and the second subrange configures S-VLANs 3000–3500. Both subranges configure the subscriber identification based on agent-circuit-identifier information.

After you issue the vlan bulk-config command with the agent-circuit-identifier keyword, the router provisions the S-VLAN IDs in the specified bulk-configured VLAN range at the same time. The router does not dynamically create the VLAN subinterface until it receives incoming data traffic. The user information is generated from the incoming data traffic that contains the agent-circuit-identifier string.

Conceptually, a VLAN subinterface in this configuration has two attributes, an S-VLAN ID and an agent-circuit-identifier string. This is analogous to a regular S-VLAN that also has two attributes, an S-VLAN ID and a VLAN ID. However, the packet that the router receives is singly-tagged with only a VLAN ID. The use of the agent-circuit-identifier keyword in the vlan bulk-config command causes the router to further examine the packet and extract the agent-circuit-identifier string in order to generate the subscriber identification information.

In a DSL access network, subscriber information can be conveyed through either of the following methods:

• VLAN encapsulation; that is, the S-VLAN ID and the VLAN ID
• Insertion of the agent-circuit-identifier string in DHCP or PPPoE messages

For example, the following configurations uniquely identify subscribers by means of VLAN encapsulation:

• Subscriber packets received from the DSLAM are single-tagged with a VLAN ID
• Subscriber packets received from the DSLAM are double-tagged with both an S-VLAN ID and a VLAN ID

The DSL Forum Technical Report (TR)-101—Migration to Ethernet-Based DSL Aggregation (April 2006) refers to the behavior of these configurations as the 1:1 forwarding model because there is a one-to-one correspondence between an individual subscriber and the VLAN encapsulation.

In contrast, the following configurations do not uniquely identify subscribers by means of VLAN encapsulation:

• Subscriber packets received from the DSLAM are single-tagged with the same VLAN ID for a group of subscribers. This configuration is typically used to implement service VLANs where the VLAN ID corresponds to the type of service for which the VLAN is used, such as voice or video. In this configuration, the VLAN ID does not correspond to an individual subscriber.
• Subscriber packets received from the DSLAM are untagged.

Instead, these configurations identify subscribers by means of the agent-circuit-identifier information present in DHCP and PPPoE control messages. DSL Forum TR-101 refers to the behavior of these configurations as the N:1 forwarding model because there is a many-to-one correspondence between subscribers and a VLAN.

Creating dynamic VLANs based on agent-circuit-identifier information enables you to manage subscribers in single-tagged or untagged N:1 configurations that do not use encapsulation to uniquely identify subscribers. In these configurations, the router intercepts the agent-circuit-identifier string from DHCP messages or from PPPoE PADR and PADI packets to build a unique subscriber interface.

For double-tagged 1:1 configurations, the router uses standard dynamic VLAN procedures to uniquely identify subscribers. In these configurations, the S-VLAN ID typically represents the DSLAM, and the VLAN ID represents the individual subscriber accessing the router through that DSLAM.

For configuration instructions, see Configuring Dynamic VLAN Subinterfaces Based on Agent Circuit Identifier Information.

Note: You must configure the DHCP local or external server to support the creation of dynamic subscriber interfaces that are based on the agent-circuit-id option (suboption 1) of the option 82 field in DHCP messages. See Configuring the DHCP Local Server or DHCP External Server Overview for information.

Dynamic Interface Creation

After you configure the base profile, you associate it with the VLAN major interface by issuing profile vlan bulk-config .

As a final step, you must issue auto-configure vlan . This command configures the VLAN major interface to support autodetection of the VLAN dynamic encapsulation type.

When the router receives an incoming data packet on a circuit, it dynamically creates the VLAN subinterface, using the attributes specified in the base profile. After examining the contents of the data packet, the router dynamically creates the required interface columns above the VLAN subinterface, using the configuration attributes contained in the nested profiles, if specified, or in the base profile itself.

Overriding Base Profile Assignments

You can also use the profile vlan override bulk-config command to assign an overriding profile to a single VLAN ID or double-tagged S-VLAN ID that exists within a bulk-configured VLAN subrange. The VLAN ID subrange that encompasses the major interface must have been previously configured with the vlan bulk-config command for use by a dynamic VLAN subinterface. After you assign the overriding profile, the router uses the information in this profile instead of the information in the previously assigned base profile to create any subsequent VLAN dynamic subinterface columns on the specified VLAN major interface, as long as they match the VLAN or S-VLAN specified in the override.

The overriding profile, like the original base profile, can include VLAN attributes, nested profile assignments, and individual characteristics for dynamic upper-interface encapsulation types.

Overriding the base profile assignment for a VLAN with a profile enables you to create a special profile for a subscriber in a DSLAM. For example, you can use the overriding profile to create dynamic VLAN subinterfaces for subscribers with an S-VLAN ID of 200 and a VLAN ID of 100.

You can also use an overriding profile with debugging attributes to troubleshoot problems with VLAN dynamic subinterface columns.

For configuration instructions and examples, see Configuring Overriding Profile Assignments for VLAN Major Interfaces.

Note: See JunosE Release Notes, Appendix A, System Maximums for information about the maximum number of overriding profile assignments currently supported per chassis.

Changing VLAN Subranges

You can add, remove, modify, merge, disable, and enable VLAN subranges within an existing bulk-configured VLAN range.

For configuration instructions and examples, see Changing VLAN Subranges.

Static VLAN Subinterfaces Within VLAN Subranges

You can configure a static VLAN subinterface with a single-tagged VLAN ID or double-tagged S-VLAN ID, or an S-VLAN ID with agent-circuit-identifier information that falls within an existing bulk-configured VLAN subrange. Conversely, you can also create a bulk-configured VLAN subrange that includes the single-tagged VLAN ID or double-tagged S-VLAN ID on a static VLAN subinterface. Configuring static VLAN subinterfaces within VLAN subranges can be useful when you want to create a column statically for users who have difficulty logging on. You might also want to configure static VLAN subinterface within a VLAN subrange as a static column to the DSLAM; the dynamic column can be for subscribers.

The following rules apply when you configure either a static VLAN subinterface within an existing bulk-configured VLAN subrange or a subrange that includes an existing static VLAN interface:

• You have no restrictions on how to configure the static VLAN subinterface.
• Static VLAN interfaces defined within a bulk-configured VLAN subrange are stored in NVS and preserved after a reboot.
• The base profile associated with the VLAN subrange does not apply to any statically defined VLAN interfaces that fall within the subrange.
• If a VLAN subrange includes a statically defined VLAN subinterface, overriding profile assignments configured for the same VLAN ID as a statically defined VLAN subinterface become inactive until the static VLAN subinterface is removed. The overriding profile becomes active again when you remove the static VLAN subinterface. You can display the current operational status (active or inactive) of overriding profile assignments by using the show vlan bulk-config command.
• Operations that add, remove, modify, merge, disable, or enable VLAN subranges within a bulk-configured VLAN range do not affect any static VLAN subinterfaces defined within the VLAN subrange.
• You cannot create a static VLAN if the single-tagged VLAN ID or double-tagged S-VLAN ID conflicts with an existing VLAN dynamic subinterface column. Such a configuration would disrupt subscribers already connected to the router via the dynamic subinterface.

For configuration information and examples, see Configuring Static VLAN Subinterfaces Within VLAN Subranges.

Configuring a Dynamic VLAN Subinterface

To configure a dynamic VLAN subinterface:

1. Configure profiles containing characteristics for the dynamic upper-interface encapsulation types to be created over the dynamic VLAN subinterface.

   These profiles are referenced in the base profile for the dynamic VLAN subinterface as nested profile assignments. For detailed instructions on creating profiles, see Configuring a Dynamic Interface from a Profile in Configuring Dynamic Interfaces.

2. (Optional) Create the profile for an upper-interface encapsulation type, and include additional profile characteristics for other encapsulation types as needed. Perform this step if you want to create a nested profile assignment in Step 5.
   host1(config)#profile myIpProfile host1(config-profile)#ip inactivity-timer 200 host1(config-profile)#ip auto-configure ip-subscriber include-primary
3. Create the base profile for the dynamic VLAN subinterface by assigning the profile a name.
   host1(config)#profile vlanBaseProfile

   This command accesses Profile Configuration mode, which enables you to configure attributes in the base profile.

4. Define attributes for the VLAN subinterface in the base profile.
   1. Configure the VLAN major interface for autodetection of the PPPoE upper-interface encapsulation type.
   2. Configure the VLAN subinterface for autodetection of the IP upper-interface encapsulation type.
   3. Configure an Ethertype value for any S-VLANs configured on the VLAN.
      host1(config-profile)#vlan auto-configure pppoe host1(config-profile)#vlan auto-configure ip host1(config-profile)#svlan ethertype 8100
5. (Optional) In the base profile, create nested profile assignments for the upper-interface encapsulation types.

   For example, the following command configures nested profile assignments for the IP upper-interface encapsulation types.

   host1(config-profile)#vlan profile ip myIpProfile
6. Exit Profile Configuration mode.
7. Configure the VLAN major interface.
   host1(config)#interface gigabitEthernet 5/0 host1(config-if)#encapsulation vlan
8. Configure a VLAN range on the major VLAN interface, and assign a name to this range.

   Note: For information about the maximum number of VLAN bulk configurations supported per chassis, see JunosE Release Notes, Appendix A, System Maximums.

   For example, the following command creates a VLAN range named myBulkConfig made up of two VLAN subranges.

   host1(config-if)#vlan bulk-config myBulkConfig vlan-range 0 100
   vlan-range 110 200
9. Assign the base profile configured for the VLAN subinterface to the VLAN range configured on the major VLAN interface.
   host1(config-if)#profile vlan bulk-config myBulkConfig vlanBaseProfile
10. Configure the VLAN major interface to support autodetection of the VLAN dynamic encapsulation type.
    host1(config-if)#auto-configure vlan

Configuring Dynamic VLAN Subinterfaces Based on Agent Circuit Identifier Information

The procedure you use to configure a dynamic VLAN subinterface that is based on agent-circuit-identification information is similar to the procedure described in Configuring a Dynamic VLAN Subinterface.

1. Configure profiles containing characteristics for the dynamic upper-interface encapsulation types to be created over the dynamic VLAN subinterface.
2. (Optional) If you want to create a nested profile assignment, create the profile for an upper-interface encapsulation type, and include additional profile characteristics for other encapsulation types as needed.
3. Create the base profile for the dynamic VLAN subinterface and enter Profile Configuration mode by assigning the profile a name.
   host1(config)#profile vlanMyBaseProfile
4. Define attributes for the VLAN subinterface in the base profile.
   1. Enable autoconfiguration for the PPPoE upper-interface encapsulation type.
   2. Enable autoconfiguration for the IP upper-interface encapsulation type.
   3. Enable autoconfiguration of VLANs that are based on agent-circuit-identifier information.
   4. (Optional) Create nested profile assignments for the upper-interface encapsulation types.
      host1(config-profile)#vlan auto-configure pppoe host1(config-profile)#vlan auto-configure ip host1(config-profile)#vlan auto-configure agent-circuit-identifier host1(config-profile)#exit host1(config)#
5. Configure the VLAN major interface.
   host1(config)#interface gigabitEthernet 5/0 host1(config-if)#encapsulation vlan
6. On the VLAN major interface, configure a VLAN range that is based on agent-circuit-identifier information, and assign a name to this range.
   host1(config-if)#vlan bulk-config myNewBulkConfig svlan-range 50 100 agent-circuit-identifier
7. Assign the base profile configured for the VLAN subinterface to the VLAN range configured on the major VLAN interface.
   host1(config-if)#profile vlan bulk-config myNewBulkConfig vlanMyBaseProfile
8. Configure the VLAN major interface to support autodetection of the VLAN dynamic encapsulation type.
   host1(config-if)#auto-configure vlan

Configuring Overriding Profile Assignments for VLAN Major Interfaces

You can assign an overriding profile to a single VLAN major interface within a bulk-configured VLAN subrange.

The overriding profile includes debugging attributes to help you identify and troubleshoot problems with the VLAN dynamic subinterface column created on the specified VLAN ID.

To assign an overriding profile to a VLAN within a bulk-configured VLAN subrange:

1. Configure both of the following:
   • Base profile for the bulk-configured dynamic VLAN on the static VLAN major interface. The VLAN range consists of one or more VLAN subranges.
   • Overriding profile for a dynamic VLAN within a bulk-configured VLAN subrange.

   For information about configuring profiles, see Configuring a Dynamic Interface from a Profile in Configuring Dynamic Interfaces.

2. Create a bulk-configured range of single-tagged VLAN IDs or double-tagged S-VLAN IDs on a static VLAN major interface. The following commands create a bulk-configured VLAN range named myBulkConfig that consists of two VLAN subranges. The first subrange encompasses VLAN IDs 150–250. The second subrange encompasses VLAN IDs 300–500.
   host1(config)#interface gigabitEthernet 4/0.101 host1(config-if)#vlan bulk-config myBulkConfig vlan-range 150 250
   vlan-range 300 500
3. Assign the previously configured base profile (vlanBaseProfile) to the bulk-configured VLAN range.
   host1(config-if)#profile vlan bulk-config myBulkConfig vlanBaseProfile
4. Assign the previously configured overriding profile to a single VLAN ID or double-tagged S-VLAN ID within the bulk-configured VLAN subrange. The following command assigns the overriding profile overrideVoiceSubscriber to the VLAN ID 202. This VLAN ID exists within the first VLAN subrange (VLAN IDs 150–250) configured in Step 2.
   host1(config-if)#profile vlan override bulk-config myBulkConfig vlan 202 overrideVoiceSubscriber

   The router now uses the information in the overriding profile instead of the information in the base profile to create subsequent VLAN dynamic subinterface columns over this VLAN ID.

5. (Optional) You can assign the same overriding profile to a VLAN ID within the same VLAN range or within a different VLAN range. For example, the following command assigns the overriding profile overrideVoiceSubscriber to the VLAN ID 160. This S-VLAN ID exists within the VLAN subrange configured in Step 2.
   host1(config-if)#profile vlan override bulk-config-name myBulkConfig
   svlan 120 202 overrideVoiceSubscriber

   Note: You can reverse the order of Step 2 and Step 4 with identical results. That is, you can assign the overriding profile to an S-VLAN ID and then assign the base profile to the entire VLAN subinterface.

6. Configure the VLAN major interface to support autodetection of the VLAN dynamic encapsulation type.
   host1(config-if)#auto-configure vlan
7. (Optional) Use the show vlan profile command to verify the overriding profile configuration.

   For more information about using this command, see Monitoring Dynamic Interfaces and Profiles.

Removing an Overriding Profile Assignment from a VLAN

You can remove an overriding profile assignment from a VLAN major interface.

If you use the overriding profile to troubleshoot the VLAN dynamic subinterface column created on the specified VLAN ID, make sure that you remove the overriding profile assignment to restore the original base profile assignment. This action ensures that subsequent VLAN dynamic subinterface columns are created using the same attributes defined in the base profile.

To remove an overriding profile assignment from a VLAN:

1. Remove the overriding profile assignment from the specified VLAN ID or S-VLAN ID.
   host1(config-if)#no profile vlan override bulk-config-name myBulkConfig vlan 202 overrideVoiceSubscriber
2. Select the dynamic VLAN subinterface on which the VLAN dynamic subinterface column resides.
   host1(config)#interface gigabitEthernet 4/0.101
3. Use the shutdown command to disable the dynamic VLAN subinterface. The shutdown command deletes the VLAN dynamic subinterface column and removes the dynamic VLAN subinterface.
   host1(config-if)#shutdown
4. Send traffic over the VLAN subinterface. This action re-creates the VLAN dynamic subinterface column with the original base profile association.

   The router now uses the information in the base profile instead of the information in the overriding profile to create subsequent VLAN dynamic subinterface columns for the specified VLAN ID or S-VLAN ID.

5. (Optional) Use the show vlan profile override command to verify the removal of the overriding profile assignment.

   For more information about using this command, see Monitoring Dynamic Interfaces and Profiles.

Removing Overriding Profile Assignments from a VLAN Range or VLAN Subrange

When you issue the no vlan bulk-config command to remove an entire VLAN range (and all VLAN subranges within that VLAN range), the router also removes any overriding profile assignments configured for VLAN IDs within those VLAN subranges. For example, the following command removes the bulk-configured VLAN range named myBulkConfig and any overriding profile assignments for VLAN IDs within the VLAN subranges belonging to myBulkConfig.

When you issue the no vlan bulk-config command to remove a particular VLAN subrange in a bulk-configured VLAN range, the router also removes any overriding profile assignments for VLAN IDs within that VLAN subrange. However, overriding profile assignments for VLAN IDs within other VLAN subranges in the VLAN range remain intact. For example, the following command removes one VLAN subrange (S-VLAN IDs 50–150 and VLAN IDs 150–250) and only those overriding profile assignments associated with this subrange.

Changing VLAN Subranges

Changing VLAN subranges within a bulk-configured VLAN range includes the following tasks:

• Adding new VLAN subranges to an existing VLAN range
• Removing VLAN subranges from an existing VLAN range
• Modifying a VLAN subrange by shortening or expanding the subrange values
• Merging multiple VLAN subranges belonging to an existing VLAN range
• Changing the administrative state of VLAN subranges

The following sections describe how to perform these tasks.

Adding VLAN Subranges

You can add a new VLAN subrange to an existing VLAN range only when the new subrange does not overlap with any existing subrange. Any overlap causes the addition to fail.

You can add multiple subranges to an existing VLAN range simultaneously. However, the entire operation fails if even one of the new subranges overlaps with an existing subrange.

The following example specifies the original VLAN subranges.

To add subranges to this bulk-configured VLAN range, you can choose either of the following methods. Each method adds a new subrange encompassing S-VLAN IDs 401–450 with VLAN ID 4 to the existing VLAN range, test.

• Specify one new subrange at a time.
  host1(config-if)#vlan bulk-config test svlan-range 401 450 4 4
• Specify the new subrange and all the existing subranges. If you use this method, all the existing subranges and their order must match exactly, or the operation fails.
  host1(config-if)#vlan bulk-config test svlan-range 201 250 2 2
  svlan-range 501 550 5 5 svlan-range 301 350 3 3 svlan-range 401 450 4 4

  The following operation fails because the order of subranges does not match the existing order.

  host1(config-if)#vlan bulk-config test svlan-range 201 250 2 2
  svlan-range 101 150 1 1 svlan-range 501 550 5 5 svlan-range 301 350 3 3 svlan-range 401 450 4 4 svlan-range 601 650 6 6

You can create a placeholder VLAN range by specifying a VLAN range name without specifying any subrange parameters. This VLAN range has no VLAN ID reservation, but you can assign a profile to it, and add subranges later as desired. The following commands illustrate this approach.

Removing VLAN Subranges

You can remove VLAN subranges from an existing VLAN range if no dynamic VLAN subinterfaces currently exists for any circuit within those subranges. The removal operation fails if any such dynamic VLAN subinterface exists. You must first remove the dynamic VLAN subinterfaces before you can remove the subranges. Removal of a subrange automatically results in the removal of all overriding profile assignments on that subrange.

You can remove only a single specific VLAN subrange at a time. The following example specifies the original VLAN subranges.

The following command removes one subrange encompassing S-VLAN IDs 101–150 with VLAN ID 1 and leaves the remaining subranges, and the named VLAN range, test, intact.

The following command removes a subrange that includes S-VLAN IDs 700–750, and that is based on agent-circuit-identifier information from the named VLAN range, test.

To remove more than one VLAN subrange, you must issue multiple removal commands, one for each subrange. You cannot remove only part of a subrange. A removal command cannot encompass more than one subrange, even if the subranges are adjacent. However, if you do not specify any subranges, you can remove all subranges in the VLAN, and the named VLAN range, at the same time.

Modifying VLAN Subranges

You can shorten or expand a subrange by modifying the subrange values of a VLAN range. You can expand a subrange if none of the VLAN IDs or S-VLAN IDs added overlap with any other subrange. You can shorten a subrange if none of the VLAN IDs or S-VLAN IDs have existing dynamic VLAN subinterfaces. You can also modify an existing subrange by configuring it to use agent-circuit-identifier information rather than a range of VLAN IDs.

You can modify only a single specific subrange at a time. The following example specifies the original VLAN subranges encompassing S-VLAN IDs 201–250 with VLAN ID 2.

The following command modifies the second subrange from S-VLAN IDs 201–250 with VLAN ID 2 to S-VLAN IDs 210–230 with VLAN IDs 2–3.

The following command modifies the third subrange from S-VLAN IDs 501–550 with VLAN ID 5 to S-VLAN IDs 501–550 with user identification that is based on agent-circuit-identifier information.

The router retains any overriding profiles assigned to a subrange after you modify the subrange if the override assignment still falls within the modified subrange. If the assignment falls outside of the newly modified subrange, the router drops the overriding profile assignment.

You cannot modify a subrange at the same time you are adding or removing a subrange. If the new modified values for a subrange partially overlap with another subrange, the operation fails and the router displays an error message.

Merging VLAN Subranges

You can merge multiple subranges of any particular VLAN range to form a single unified subrange, conserving subrange resources. Merging takes place only when you modify a subrange so that it completely includes at least one other subrange of the same VLAN range. The merged subranges do not need to be adjacent to each other.

If the encompassing subrange has any VLAN IDs or S-VLAN IDs that are outside the subranges to be merged, those VLAN IDs or S-VLAN IDs are added. The encompassing subrange must cover a subrange completely to incorporate it in the merged subrange. The merge operation fails if the encompassing subrange completely overlaps some subranges but only partially overlaps with another subrange. The encompassing subrange does not have to encompass all subranges of the VLAN range.

Each subrange that is merged with another frees up a subrange. E Series routers currently support a maximum of 300 bulk-configured VLAN ranges per chassis. Therefore, if a VLAN range consists of 5 subranges, 295 subranges are still available for subsequent configuration. If you merge 2 of those subranges, resulting in a new total of 4 subranges in the VLAN range, then 296 subranges are available for configuration.

The router retains any overriding profile assignments on the subranges made before the merger, and applies them to the new merged subrange. You can separate merged subranges either by removing the merged subrange and then adding new separate subranges or by modifying the merged subrange to remove some portion of the subrange and then adding a new subrange.

The following example specifies the original VLAN subranges.

The following command merges two subranges (S-VLAN IDs 101–150 and VLAN ID 1) and (S-VLAN IDs 201–250 and VLAN ID 2) and effectively replaces them with the new subrange encompassing S-VLAN IDs 101–250 and VLAN IDs 1–2.

To separate the merged subranges, you can modify the unified subrange and add subranges as needed, provided that no dynamic VLAN subinterfaces currently exist for any VLAN ID within those subranges.

If you merge subranges by using SNMP, the new merged subrange takes the lowest instance value of the incorporated subranges. For example, if a VLAN range has three subranges with instance values of 2, 4, and 5 and the subranges with instance values of 2 and 5 are merged, the new merged subrange has an instance value of 2.

Changing the Administrative State of VLAN Subranges

VLAN subranges have an administrative state that enables you to remove dynamic VLAN subinterfaces on various subranges that belong to a single VLAN range. This functionality is important because subrange removal requires that no dynamic VLAN subinterfaces exist for any circuit on that subrange. The removal operation fails if any such interfaces exist.

By default, the administrative state of a VLAN subrange is up. When you change the administrative state to down by using the vlan bulk-config shutdown command, the router deletes all dynamic VLAN subinterfaces on the affected subranges. You can use the show vlan subinterface command to monitor the progress of the removal of all dynamic VLAN subinterfaces for the specified subrange.

No additional dynamic VLAN subinterfaces can be created for the subrange until you restore the administrative state to up by using the no vlan bulk-config shutdown command.

The following example specifies the original VLAN subranges.

You cannot specify a partial subrange; the specified subrange must exactly match a subrange that has already been configured. The following command changes the administrative state of the second subrange (S-VLAN IDs 201–250 and VLAN ID 2) to down. The router removes all dynamic interface columns built on any of the VLAN IDs or S-VLAN IDs in this subrange. No additional dynamic VLAN subinterfaces can be created until you change the administrative state to up.

The following command changes the administrative state of this same VLAN subrange to up.

You can also change the administrative state of VLAN subranges that are based on agent-circuit-identifier information. For example, assume that the following command is issued to configure a VLAN subrange based on agent-circuit-identifier information:

The following command changes the administrative state of this same VLAN subrange to down:

You can change the administrative state of all subranges in a bulk-configured VLAN range at the same time by issuing the command without specifying any subranges. When you shut down a named bulk configuration, all VLAN ranges belonging to that bulk configuration, including those based on double-tagged S-VLANs or agent-circuit-identifier information, are disabled.

The following command shuts down all four subranges belonging to the named VLAN range, test, regardless of their current state.

The time required for the router to complete an administrative state change depends on the number of VLAN subranges configured.

Configuring Static VLAN Subinterfaces Within VLAN Subranges

You can do either of the following on an E Series router:

• Create a static VLAN subinterface within an existing bulk-configured VLAN subrange
• Create a bulk-configured VLAN subrange that includes an existing static VLAN subinterface

The following sections describe how to perform these tasks.

The example procedures in this section show how to configure static VLAN subinterfaces within VLAN subranges by using the same loopback interface referenced by multiple unnumbered IP interfaces. Instead of assigning a different IP address to each physical interface, the first example assigns an IP address to a loopback interface (loopback 0). Each physical interface is then configured as an unnumbered IP interface, referencing the same loopback interface.

Creating Static VLAN Subinterfaces Within VLAN Subranges

You can configure a static VLAN subinterface with a VLAN whose VLAN ID falls within an existing bulk-configured VLAN subrange.

To create a static VLAN subinterface within a VLAN subrange:

1. Create the VLAN major interface.
   host1(config)#interface gigabitEthernet 0/0 host1(config-if)#encapsulation vlan
2. Create a bulk-configured VLAN range that includes one or more VLAN subranges.
   host1(config-if)#vlan bulk-config test vlan-range 200 250
3. Create a static VLAN subinterface by adding a subinterface number to the interface identification command.
   host1(config-if)#interface gigabitEthernet 0/0.2100
4. Do one of the following:
   • Assign a VLAN ID for the subinterface.
     host1(config-if)#vlan id 201
   • Assign a VLAN ID and the optional unique MAC address for the subinterface.
     host1(config-if)#vlan id 201 mac-address 0090.1a01.1234
5. To fully configure the VLAN subinterface, assign an IP address, or make it unnumbered.
   host1(config-if)#ip unnumbered loopback 0

Creating VLAN Subranges That Include Static VLAN Subinterfaces

You can configure a bulk-configured VLAN subrange that includes the VLAN ID belonging to an existing VLAN on a static VLAN subinterface. This example is essentially the reverse of the procedure in Creating Static VLAN Subinterfaces Within VLAN Subranges.

To create a VLAN subrange that includes a static VLAN subinterface:

1. Create the VLAN major interface.
   host1(config)#interface gigabitEthernet 3/1 host1(config-if)#encapsulation vlan
2. Specify a static VLAN subinterface.
   host1(config-if)#interface gigabitEthernet 3/1.201
3. Do one of the following:
   • Assign a VLAN ID for the subinterface.
     host1(config-if)#vlan id 201
   • Assign a VLAN ID and the optional unique MAC address for the subinterface.
     host1(config-if)#vlan id 201 mac-address 0090.1a01.1234
4. Create a bulk-configured VLAN range that includes the VLAN ID of the previously configured VLAN. In this example, the VLAN range 100–250 includes VLAN ID 201.
   host1(config)#interface gigabitEthernet 3/1 host1(config-if)#vlan bulk-config test2 vlan-range 100 250
5. To fully configure the VLAN subinterface, assign an IP address or make it unnumbered.
   host1(config-if)#ip unnumbered loopback 0