To run Multitopology Routing (MTR), you must configure IP routing. Multitopology Routing supports OSPF version 2 (OSPFv2), static routes, and BGP. You must configure an interior gateway protocol (IGP), such as OSPFv2 or static routing. Configure BGP to add routes learned through BGP to the appropriate custom topologies.
OSPF in MTR uses a single instance of OSPF to carry connectivity and IP reachability information for different topologies. That information is used to calculate shortest-path-first (SPF) trees and routing tables. OSPF for MTR supports protocol extensions that include metrics that correspond to different topologies for link and prefix reachability information. The type-of-service (TOS) metric field is used to advertise the topology-specific metric for links and prefixes belonging to that topology. The TOS field is redefined as MT-ID in the payload of router, summary, and Type 5 and Type 7 autonomous-system-external link-state advertisements (LSAs).
BGP in MTR provides the ability to resolve BGP routes against configured topologies. An inbound policy is used to select routes for inclusion in the appropriate routing tables for the topologies.
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Note: Multitopology Routing is also supported on logical systems and the virtual router routing instance. No other routing instance type is supported on Multitopology Routing. For more information about configuring logical systems, see Logical System Overview. For more information about configuring routing instances see, Routing Instances Configuration Guidelines. For more information about configure a virtual router instance, see the JUNOS VPNs Configuration Guide. |
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