Configuring router serial interfaces

Attach the QoS policy-map with compress header ip action using the service-policy output command. This task describes the commands used to bring up a serial interface. The configuration on both ends of the serial connection must match for the interface to be active. Use this command to also confirm that the router recognizes the PLIM card. Assigns an IP address and subnet mask to the interface.

Skip this step if you are configuring Frame Relay encapsulation on this interface. For Frame Relay, the IP address and subnet mask are configured under the subinterface. Removal of the shutdown configuration eliminates the forced administrative down on the interface, enabling it to move to an up or down state assuming the parent SONET layer is not configured administratively down. When you issue the end command, the system prompts you to commit changes:.

Use the commit command to save the configuration changes to the running configuration file and remain within the configuration session. Exits interface configuration mode and enters global configuration mode. Exits global configuration mode and enters EXEC mode. Repeat Step 1 through Step 8 to bring up the interface at the other end of the connection.

The configuration on both ends of the serial connection must match. Verifies that the interface is active and properly configured. Optional Displays the interface configuration.

This task describes the commands used to modify the default configuration on a serial interface. The default encapsulation is hdlc. Optional Enters serial submode to configure the serial parameters. Optional Specifies the length of the cyclic redundancy check CRC for the interface. Optional Enables payload scrambling on the interface.

Payload scrambling is disabled on the interface. Optional Specifies a transmit delay on the interface. Values can be from 0 to Transmit delay is disabled by default the transmit delay is set to 0. Optional Displays general information for the specified serial interface.

The procedure in this section creates a point-to-point serial subinterface and configures a permanent virtual circuit PVC on that serial subinterface. Only one PVC can be configured for each point-to-point serial subinterface. Enters serial subinterface configuration mode. Assigns an IP address and subnet mask to the subinterface. Replace dlci with a PVC identifier, in the range from 16 to Only one PVC is allowed per subinterface.

Repeat Step 1 through Step 5 to bring up the serial subinterface and any associated PVC at the other end of the connection. When assigning an IP address and subnet mask to the subinterface at the other end of the connection, keep in mind that the addresses at both ends of the connection must be in the same subnet.

This task describes the commands you can use to modify the default configuration on a serial PVC. Enters subinterface configuration mode for the PVC. Attaches a policy map to an input subinterface or output subinterface. Once attached, the policy map is used as the service policy for the subinterface. Repeat Step 1 through Step 6 to bring up the serial subinterface and any associated PVC at the other end of the connection.

The configuration on both ends of the subinterface connection must match. Optional Verifies the configuration of specified serial interface. Optional Displays the statistics and the configurations of the input and output policies that are attached to a subinterface. Use this procedure to modify that default keepalive interval. Cisco HDLC is enabled by default on serial interfaces. Specifies the number of seconds between keepalive messages.

Use the keepalive disable command, the no keepalive , or the keepalive command with an argument of 0 to disable the keepalive feature. The range is from 1 to 30 seconds. The default is 10 seconds. If keepalives are configured on an interface, use the no keepalive command to disable the keepalive feature before configuring Frame Relay encapsulation on that interface.

Optional Verifies the interface configuration. This section contains the following step procedures:. Configures the maximum number of compressed IP header packets that are exchanged on a link before the IPHC context is refreshed. Configures the maximum time between context refreshes. Enables the configured context refresh settings for RTP packets.

Disables the IPHC context status feedback messages on an interface. Configures the maximum size in bytes of a compressed IP header. This section describes how to enable an IP header compression IPHC profile on an interface by attaching the profile directly to the interface.

Use the show interfaces command to see a list of all interfaces currently configured on the router. For more information about the syntax for the router, use the question mark? Specifies Layer 2 encapsulation for the interface. Only output service policies are allowed. This section provides the following configuration examples:. The following example shows how to configure the interval between keepalive messages to be 10 seconds:.

The following example shows how to modify the optional serial interface parameters:. The following is sample output from the show interfaces serial command:. The following example shows how to create a serial interface on a SPA with Frame Relay encapsulation and a serial subinterface with a PVC on router The following example shows how to create a serial interface on a SPA with Frame Relay encapsulation and a serial subinterface with a PVC on router 2, which is connected to router The following example shows how to create and configure a serial interface with PPP encapsulation:.

The following example shows how to enable an IP header compression IPHC profile on a serial interface by attaching the profile directly to the interface:. Skip to content Skip to search Skip to footer. Book Contents Book Contents. Find Matches in This Book. PDF - Complete Book Updated: November 30, Chapter: Configuring Serial Interfaces.

Configuring Serial Interfaces This module describes the configuration of serial interfaces. Release 4. You can find the possible values by using help. All interfaces have a bandwidth value assigned to them. For LAN-based interfaces, the speed of the interface becomes the bandwidth value In kilobits per second Kbps.

However, on synchronous serial interfaces, the bandwidth defaults to 1,Kbps and this is not related with the clock rate set. To change the bandwidth value for an interface, use the bandwidth Interface Subconfiguration mode command:. Like us on. We use cookies on our website to give you the most relevant experience by remembering your preferences and repeat visits. Manage consent. Close Privacy Overview This website uses cookies to improve your experience while you navigate through the website.

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