Juniper Network Operating System (JUNOS) maintains different types of routing tables for clear separation of different types of routes. Each routing table populates a portion of forwarding table and thus the forwarding table is partitioned based on routing table. The routing table in Juniper Network Operating System or JUNOS contains all the information known by that router and routing protocol puts the different routes in the routing table for single destination. Further the routing table places the best route in the packet forwarding engine (PFE).
Below is the list of different types of routing tables created by Junos. They are as follows:
1. Inet.0: This table stores the IPv4 unicast routes. This is equivalent to global routing table in CISCO.
2. Inet.1: This table stores the multicast routes. This table stores the (S,G) entries. This is equivalent to mroute table of CISCO.
3. Inet.2: This table is used for unicast RPF (Reverse Path Forwarding). For subsequent address family indicator (SAFI) 2 routes, when multiprotocol BGP (MBGP) is enabled. This table stores unicast routes that are used for multicast reverse-path-forwarding (RPF) lookup. The routes in this table can be used by the Distance Vector Multicast Routing Protocol (DVMRP), which requires a specific RPF table. In contrast, Protocol Independent Multicast (PIM) does not need this table because it can perform RPF checks against the inet.0 table. You can import routes from inet.0 into inet.2 using routing information base (RIB) groups, or install routes directly into inet.2 from a multicast routing protocol.
4. Inet.3: For IPv4 MPLS. This table stores the egress address of an MPLS label-swiched path (LSP), the LSP name, and the outgoing interface name. This routing table is used only when the local device is the ingress node to an LSP.