JN0-280 Exam Dumps : Data Center, Associate (JNCIA-DC)

Filter-Based Forwarding (FBF) in Junos OS allows traffic to be routed based on specific criteria such as source address, rather than just the destination address. This is useful in scenarios like policy routing or providing multiple paths for different types of traffic.

Step-by-Step Breakdown:

Instance-Type Forwarding:You must create aninstance-type forwardingrouting instance. This routing instance allows for different routing tables based on the incoming packet filter.

Command:

set routing-instances FBF-instance instance-type forwarding

Match Filter:You need to create afilterto match the traffic that will be forwarded according to your custom routing policy. This filter is applied to an interface to determine which traffic will use the custom forwarding instance.

Command Example:

set firewall family inet filter FBF-filter term 1 from source-address

Bidirectional Forwarding Detection (BFD)is a network protocol used to detect failures in the network path between two devices quickly.

Step-by-Step Breakdown:

Path Failure Detection:BFD provides a low-overhead mechanism for detecting failures in forwarding paths across Layer 3 networks. It is much faster than traditional routing protocol timers and can detect failures within milliseconds.

BFD in Routing:BFD can be integrated with routing protocols like OSPF, BGP, or IS-IS to trigger a faster convergence when a network path goes down.

Juniper Reference:

BFD Configuration: Juniper devices use BFD to monitor network paths and ensure fast failure detection, enhancing network resilience.

Aggregate routesandgenerated routesare used to create summarized routes in Junos, but they behave differently in terms of forwarding.

Step-by-Step Breakdown:

Aggregate Routes:

Anaggregate routesummarizes a set of more specific routes, but it does not have a direct forwarding next hop. Instead, it points to the more specific routes for actual packet forwarding.

Generated Routes:

Agenerated routealso summarizes specific routes, but it has aforwarding next hopthat is determined based on the availability of contributing routes. The generated route can be used to directly forward traffic.

Juniper Reference:

Aggregate and Generated Routes: In Junos, aggregate routes rely on more specific routes for forwarding, while generated routes can forward traffic directly based on their next-hop information.