System Interface

The system interface is associated with the network entity (such as a specific Nokia router), not a specific interface. The system interface is also referred to as the loopback address. The system interface is associated during the configuration of the following entities:

The system interface is used to preserve connectivity (when routing reconvergence is possible) when an interface fails or is removed. The system interface is used as the router identifier. A system interface must have an IP address with a 32-bit subnet mask.

Network Interface

A network interface can be configured on one of the following entities a physical port or LAG:

For the 7950 XRS, a network interface can be configured on either a physical port or Ethernet LAG interface.

Configuring a System Name

Use the system command to configure a name for the device. The name is used in the prompt string. Only one system name can be configured. If multiple system names are configured, the last one configured will overwrite the previous entry.

If special characters are included in the system name string, such as spaces, #, or ?, the entire string must be enclosed in double quotes. Use the following CLI syntax to configure the system name:

The following example displays the system name output.

Configuring Interfaces

The following command sequences create a system and a logical IP interface. The system interface assigns an IP address to the interface, and then associates the IP interface with a physical port. The logical interface can associate attributes like an IP address or port.

The system interface cannot be deleted.

Deriving the Router ID

The router ID defaults to the address specified in the system interface command. If the system interface is not configured with an IP address, then the router ID inherits the last four bytes of the MAC address. The router ID can also be manually configured in the config>router router-id context. On the BGP protocol level, a BGP router ID can be defined in the config>router>bgp router-id context and is only used within BGP.

If a new router ID is configured, protocols are not automatically restarted with the new router ID. The next time a protocol is initialized the new router ID is used. An interim period of time can occur when different protocols use different router IDs. To force the new router ID, issue the shutdown and no shutdown commands for each protocol that uses the router ID, or restart the entire router.

It is possible to configure an SR OS to operate with an IPv6 only BOF and no IPv4 system interface address. When configured in this manner, the operator must explicitly define IPv4 router IDs for protocols such as OSPF and BGP as there is no mechanism to derive the router ID from an IPv6 system interface address.

Use the following CLI syntax to configure the router ID:

The following example displays a router ID configuration:

Configuring a Confederation

Configuring a confederation is optional. The AS and confederation topology design should be carefully planned. Autonomous system (AS), confederation, and BGP connection and peering parameters must be explicitly created on each participating router. Identify AS numbers, confederation numbers, and members participating in the confederation.

Refer to the BGP section for CLI syntax and command descriptions.

Use the following CLI syntax to configure a confederation:

The following example displays the commands to configure the confederation topology diagram displayed in Confederation Configuration.

Note: Confederations can be preconfigured prior to configuring BGP connections and peering. Each confederation can have up to 15 members.

The following displays a confederation example.

Configuring an Autonomous System

Configuring an autonomous system is optional. Use the following CLI syntax to configure an autonomous system:

The following displays an autonomous system configuration example:

Configuring Overload State on a Single SFM

A 7450 ESS or 7750 SR with a single SFM installed has a system multicast throughput that is only a half of a system with dual SFMs installed. For example, in a mixed environment in which IOM1s, IOM2s, and IOM3s are installed in the same system (chassis mode B or C), system multicast throughput doubles when redundant SFMs are used instead of a single SFM. If the required system multicast throughput is between 16G and 32G (which means both SFMs are being actively used), when there is an SFM failure, multicast traffic needs to be rerouted around the node.

Some scenarios include:

You can use an overload state in IGP to trigger the traffic reroute by setting the overload bit in IS-IS or setting the metric to maximum in OSPF. Since PIM uses IGP to find out the upstream router, a next-hop change in IGP will cause PIM to join the new path and prune the old path, which effectively reroutes the multicast traffic downstream. When the problem is resolved, the overload condition is cleared, which will cause the traffic to be routed back to the router.

Changing the System Name

The system command sets the name of the device and is used in the prompt string. Only one system name can be configured. If multiple system names are configured, the last one configured will overwrite the previous entry.

Use the following CLI syntax to change the system name:

The following example displays the command usage to change the system name:

The following example displays the system name change:

Modifying Interface Parameters

Starting at the config>router level, navigate down to the router interface context.

To modify an IP address, perform the following steps:

To modify a port, perform the following steps:

The following example displays the interface configuration:

Deleting a Logical IP Interface

The no form of the interface command typically removes the entry, but all entity associations must be shut down and/or deleted before an interface can be deleted.