Example: Configuring Dynamic Subscriber Interfaces

Example: Configuring Dynamic Subscriber Interfaces over Ethernet

This example shows how you can configure a dynamic subscriber interface in an IP over Ethernet configuration by using DHCP events.

• Requirements
• Overview
• Configuring Dynamic Subscriber Interfaces over Ethernet

Requirements

• JunosE Release 7.1.0 or higher-numbered releases
• E Series router (ERX7xx models, ERX14xx models, the ERX310 router, the E120 router, or the E320 router)
• ASIC-based line modules that support Fast Ethernet or Gigabit Ethernet

Overview

Figure 1 shows the interface stack built for this configuration.

Figure 1: IP over Ethernet Dynamic Subscriber Interface Configuration

Configuring Dynamic Subscriber Interfaces over Ethernet

Step-by-Step Procedure

1. Configure the DHCP server.

   For instructions, see Configuring the DHCP Local Server .

2. Specify a Fast Ethernet, Gigabit Ethernet, or 10-Gigabit Ethernet port.
   host1(config)#interface fastEthernet 4/1

   Use the no version to remove IP from an interface or subinterface. You must issue the no version from the highest level down; you cannot remove an interface or a subinterface if the one above it still exists.

3. Create the primary IP interface by assigning an IP address and mask to the Ethernet interface (or make it unnumbered).
   host1(config-if)#ip address 192.168.2.1 255.255.255.0

   You must specify the layer 2 encapsulation before you set the IP address. Issuing this command creates the primary IP interface. You must create a primary IP interface on which to enable dynamic creation of subscriber interfaces.

   Use the no version to remove the IP address or to disable IP processing.

4. Configure the primary IP interface to enable dynamic creation of subscriber interfaces.
   host1(config-if)#ip auto-configure ip-subscriber

   The router creates the required dynamic subscriber interfaces when the IP address is assigned to the associated subscriber. The address might be assigned by an external DHCP server, the DHCP local server, or the packet detect feature.

   Use the include-primary keyword to specify that the primary interface can be assigned to a subscriber. Use the exclude-primary keyword to specify that the primary interface is not used for subscribers. The primary interface is not assigned to a subscriber by default. You can issue this command from Interface Configuration mode, Subinterface Configuration mode, or Profile Configuration mode.

   Use the no version to disable creation of dynamic subscriber interfaces associated with this primary IP interface. Use the no version with the include-primary keyword to specify that the primary interface is not assigned to a subscriber.

5. (Optional) Append the virtual router name to the subscriber interface in case of DSI configuration.
   host1(config-if)#ip auto-configure append-virtual-router-name

   You can use this command to allow more than one subscriber to have the same IP address across different virtual routers in the DSI configuration by appending the virtual router name to the interface. You can issue this command from either Interface Configuration mode or Profile Configuration mode.

   Use the no version to disable ip auto-configure on the static primary interface if it is already configured. This feature is enabled by default in a non-DSI configuration with the DHCP local server.

6. (Optional) Specify the source address of traffic that is destined for the primary IP interface.
   host1(config-if)#ip source-prefix 192.168.2.1 255.255.255.0

   You can use this command to configure a subscriber interface or a primary IP interface enabled for dynamic creation of subscriber interfaces to demultiplex traffic with the specified source address. Use the no version to remove the association between the interface and the specified IP source address and mask.

Example: Configuring Dynamic Subscriber Interfaces over VLANs

This example shows how you can configure a dynamic subscriber interface in an IP over VLAN over Ethernet configuration by using DHCP events.

• Requirements
• Overview
• Configuring Dynamic Subscriber Interfaces over VLANs

Requirements

• JunosE Release 7.1.0 or higher-numbered releases
• E Series router (ERX7xx models, ERX14xx models, the ERX310 router, the E120 router, or the E320 router)
• ASIC-based line modules that support Fast Ethernet or Gigabit Ethernet

Overview

Figure 2 shows the interface stack built for this configuration.

Figure 2: IP over VLAN over Ethernet Dynamic Subscriber Interface Configuration

Configuring Dynamic Subscriber Interfaces over VLANs

Step-by-Step Procedure

1. Configure the DHCP server.

   For instructions, see Configuring the DHCP Local Server .

2. Specify a Fast Ethernet, Gigabit Ethernet, or 10-Gigabit Ethernet port.
   host1(config)#interface gigabitEthernet 1/0

   Note: You can configure only the primary port, 0, on the Gigabit Ethernet module. The router automatically uses the redundant port if the primary port fails.

   Use the no version to remove IP from an interface. You must issue the no version from the highest level down; you cannot remove an interface or a subinterface if the one above it still exists.

3. Specify VLAN as the encapsulation method on the interface. This command creates the VLAN major interface.
   host1(config-if)#encapsulation vlan

   Use the no version to disable VLAN encapsulation on the interface.

4. Create a VLAN subinterface by adding a subinterface number to the interface identification command.
   host1(config-if)#interface gigabitEthernet 1/0.1
5. Assign a unique VLAN ID to the VLAN subinterface.
   host1(config-if)#vlan id 101

   You need to specify a VLAN ID number that is in the range 0–4095 and is unique within the Ethernet interface. Issue the vlan id command before you configure any upper-layer interfaces, such as IP.

   There is no no version.

6. Create the primary IP interface by assigning an IP address and mask to the VLAN subinterface (or make it unnumbered).
   host1(config-if)#ip address 192.168.2.10 255.255.255.0

   You must specify the layer 2 encapsulation before you set the IP address. Issuing this command creates the primary IP interface. You must create a primary IP interface on which to enable dynamic creation of subscriber interfaces.

   Use the no version to remove the IP address or to disable IP processing.

7. (Optional) Append the virtual router name to the subscriber interface in case of DSI configuration.
   host1(config-if)#ip auto-configure append-virtual-router-name
8. (Optional) Specify the source address of traffic that is destined for the primary IP interface.
   host1(config-if)#ip source-prefix 192.168.2.10 255.255.255.0

   You can use this command to configure a subscriber interface or a primary IP interface enabled for dynamic creation of subscriber interfaces to demultiplex traffic with the specified source address. Use the no version to remove the association between the interface and the specified IP source address and mask.

Example: Configuring Dynamic Subscriber Interfaces over Bridged Ethernet

This example shows how you can configure a dynamic subscriber interface in an IP over bridged Ethernet over ATM configuration by using DHCP events.

• Requirements
• Overview
• Configuring Dynamic Subscriber Interfaces over Bridged Ethernet

Requirements

• JunosE Release 7.1.0 or higher-numbered releases
• E Series router (ERX7xx models, ERX14xx models, the ERX310 router, the E120 router, or the E320 router)
• ASIC-based line modules that support Fast Ethernet or Gigabit Ethernet

Overview

Figure 3 shows the interface stack built for this configuration.

Figure 3: IP over Bridged Ethernet over ATM Dynamic Subscriber Interface Configuration

Configuring Dynamic Subscriber Interfaces over Bridged Ethernet

Step-by-Step Procedure

1. Configure the DHCP server.

   For instructions, see Configuring the DHCP Local Server .

2. Create an ATM major interface.
   host1(config)#interface atm 3/3
3. Create an ATM 1483 subinterface.
   host1(config-if)#interface atm 3/3.1
4. Configure an associated PVC for the ATM 1483 subinterface by specifying the VCD, the VPI, the VCI, and the encapsulation type.
   host1(config-subif)#atm pvc 10 100 22 aal5snap

   Specify the VCD, the VPI, the VCI, and the encapsulation type. (For more information about these parameters, see the Creating a Basic Configuration section in JunosE Link Layer Configuration Guide .)

   Use the no version to remove the specified PVC.

5. Specify bridged Ethernet as the encapsulation method on the ATM 1483 subinterface.
   host1(config-subif)#encapsulation bridge1483

   Use the no version to remove bridged Ethernet as the encapsulation method on the interface.

6. Create the primary IP interface by assigning an IP address and mask to the bridged Ethernet interface (or make it unnumbered).
   host1(config-subif)#ip address 192.168.2.20 255.255.255.0

   You must specify the layer 2 encapsulation before you set the IP address. Issuing this command creates the primary IP interface. You must create a primary IP interface on which to enable dynamic creation of subscriber interfaces.

   Use the no version to remove the IP address or to disable IP processing.

7. Configure the primary IP interface to enable dynamic creation of subscriber interfaces.
   host1(config-subif)#ip auto-configure ip-subscriber
8. (Optional) Append the virtual router name to the subscriber interface in case of DSI configuration.
   host1(config-if)#ip auto-configure append-virtual-router-name
9. (Optional) Specify the source address of traffic that is destined for the primary IP interface.
   host1(config-subif)#ip source-prefix 192.168.2.20 255.255.255.0

   You can use this command to configure a subscriber interface or a primary IP interface enabled for dynamic creation of subscriber interfaces to demultiplex traffic with the specified source address. Use the no version to remove the association between the interface and the specified IP source address and mask.

Example: Configuring Dynamic Subscriber Interfaces over GRE Tunnels

This example shows how you can configure a dynamic subscriber interface in a GRE tunnel configuration by using packet detection.

• Requirements
• Overview
• Configuring Dynamic Subscriber Interfaces over GRE Tunnels

Requirements

• JunosE Release 7.1.0 or higher-numbered releases
• E Series router (ERX7xx models, ERX14xx models, the ERX310 router, the E120 router, or the E320 router)
• ASIC-based line modules that support Fast Ethernet or Gigabit Ethernet

Overview

Figure 4 shows the interface stack built for this configuration.

Figure 4: GRE Tunnel Dynamic Subscriber Interface Configuration

Configuring Dynamic Subscriber Interfaces over GRE Tunnels

Step-by-Step Procedure

1. Create a GRE tunnel interface.

   For instructions, see the Configuration Tasks section in JunosE IP Services Configuration Guide .

2. Create the primary IP interface by assigning an IP address and mask to the bridged Ethernet interface (or make it unnumbered).
   host1(config-subif)#ip address 192.168.2.20 255.255.255.0

   You must specify the layer 2 encapsulation before you set the IP address. Issuing this command creates the primary IP interface. You must create a primary IP interface on which to enable dynamic creation of subscriber interfaces.

   Use the no version to remove the IP address or to disable IP processing.

3. Configure the packet detect feature and specify that IP automatically detect packets that do not match any entries in the demultiplexer table.
   host1(config-if)#ip auto-detect ip-subscriber

   When an unmatched packet is detected, an event is generated that determines whether to create a dynamic subscriber interface.

   Use the no version to restore the default, in which packet detection is disabled.

4. Configure the primary IP interface to enable dynamic creation of subscriber interfaces.
   host1(config-subif)#ip auto-configure ip-subscriber
5. (Optional) Append the virtual router name to the subscriber interface in case of DSI configuration.
   host1(config-if)#ip auto-configure append-virtual-router-name
6. (Optional) Specify the IP inactivity timer.
   host1(config-subif)#ip inactivity-timer 100

   A dynamically created subscriber interface is deleted if it is inactive for a period longer than the inactivity timer value. The timer value can be in the range 1–65335 minutes. A timer value of 0 specifies that dynamically created subscriber interfaces are never deleted by the inactivity timer.

   Use the no version to restore the default, in which inactivity timer feature is disabled.

7. (Optional) Specify the source address of traffic that is destined for the primary IP interface.
   host1(config-subif)#ip source-prefix 192.168.2.1 255.255.255.0

   You can use this command to configure a subscriber interface or a primary IP interface enabled for dynamic creation of subscriber interfaces to demultiplex traffic with the specified source address. Use the no version to remove the association between the interface and the specified IP source address and mask.