Modular Database (MDB)

Note: MDB profiles are supported only on 7250 IXR Gen 3 and 7250 IXR Gen 2c+ platforms.

Datapath tables used to store forwarding, routing and related entries, such as ARP/ND tables, IP FIB, can be re-partitioned to support different scale profiles. These tables are all governed by the Modular Database (MDB). MDB determines how datapath resources are allocated across different lookup tables. The datapath lookup tables are essential for packet forwarding, such as IP routing, MAC addresses, MPLS NHLFEs, and VPN labels, among others. With a different MDB profile, resources can be reallocated across lookup tables, allowing a specific table to accommodate more entries based on network deployment use cases.

For example, in deployments that require a large IP FIB, the resources allocated to other use-cases such as MPLS, MAC-VRF Forwarding Database (FDB) can be trimmed down or even zeroed out to support a higher IP FIB scale.

7250 IXR platforms support different MDB profiles. During system boot-up, based on the MDB profile configuration, the router datapath resources are allocated for specific deployment needs.

MDB profile update requires a system reboot for changes to take effect.

The SR Linux routers support both default and custom profiles optimized to meet specific network requirements. For details on supported profiles, see MDB profiles.

MDB profiles

The following MDB profiles are supported:

Table 1. Profile ID allocation for 7250 IXR Gen 2c+ platforms
Profile ID	Description
1	General-purpose default profile suitable for most use cases, including support for BGP-LU and SR-MPLS applications
2	Provides support to manage fallback routing, achieved through a secondary FIB lookup in the default network instance (`system.datapath.secondary-default-lookup`)
3	Distinguished by its support for IP multicast and supports a higher number of MPLS ILM entries, suitable for BGP Labeled Unicast (BGP-LU) and SR-MPLS applications.

Table 2. Profile ID allocation for 7250 IXR Gen 3 platforms
Profile ID	Description
1	General-purpose default profile suitable for most use cases.
4	Optimized for MPLS and labeled prefix use cases while maintaining a large FIB.

Configuring an MDB profile

To configure MDB profiles, set the parameter id value within the context platform.resource-management.mdb-profile to an applicable profile ID and reboot the node for the new profile to be active.

Note: The chassis-reboot-required within the context platform.resource-management.mdb-profile is automatically set to true when a new MDB profile ID is configured.

Display the active MDB profile ID

The following configuration examples displays the configured active MDB profile ID.

--{ + running }--[  ]--
# info with-context platform resource-management mdb-profile
    platform {
        resource-management {
            mdb-profile {
                id 1
            }
        }
    }