You want to enable a Junos device to support aggregated Ethernet interfaces. In this scenario, which configuration hierarchy would you use?
To configure aggregated Ethernet (AE) interfaces on a Junos device, the configuration is done under the [edit chassis] hierarchy.
Step-by-Step Breakdown:
Chassis Configuration:
The chassis configuration is responsible for enabling the hardware to support Link Aggregation Groups (LAGs), allowing multiple physical interfaces to be bundled into a single logical interface for load balancing and redundancy.
Command Example:
set chassis aggregated-devices ethernet device-count <number>
This command enables a specific number of aggregated Ethernet interfaces on the device.
Juniper Reference:
LAG Configuration in Junos: The chassis hierarchy is used to allocate and manage hardware resources for aggregated Ethernet interfaces in Juniper devices.
Within your router, you want to verify that you are learning routes from a remote BGP peer at IP address 10.10.100.1. Which command would satisfy the requirement?
To verify that your router is learning routes from a remote BGP peer at a specific IP address (e.g., 10.10.100.1), the correct command to use is show route receive-protocol bgp.
Step-by-Step Breakdown:
BGP Route Learning:
The show route receive-protocol bgp command displays the routes that have been received from a specified BGP peer. This helps in confirming that the remote peer is sending routes correctly and that your router is receiving them.
Command Example:
show route receive-protocol bgp 10.10.100.1
This will show all routes that have been received from the BGP peer with IP address 10.10.100.1.
Juniper Reference:
BGP Route Verification: Use this command to troubleshoot and verify that routes from a specific BGP peer are being received.
When evaluating BGP routes, what will be evaluated first?
In BGP (Border Gateway Protocol), when evaluating multiple routes to the same destination, the first attribute that is considered is the local preference value. The local preference is a BGP attribute used to influence outbound routing decisions within an Autonomous System (AS).
Step-by-Step Breakdown:
Local Preference:
The local preference attribute is used to determine which path is preferred for traffic leaving the AS. The higher the local preference value, the more preferred the route.
BGP Path Selection:
The BGP path selection process evaluates the following attributes in this order:
Local Preference (higher is preferred)
AS Path (shorter is preferred)
Origin (IGP > EGP > incomplete)
MED (Multi-Exit Discriminator) (lower is preferred)
Juniper Reference:
BGP Path Selection: In Junos, the local preference attribute is the first to be evaluated when determining the best path for outbound traffic.
Which statement is correct about IBGP?
In IBGP (Internal Border Gateway Protocol), all routers within the same AS (Autonomous System) must have a logical full-mesh topology. This means that every IBGP router must be able to communicate with every other IBGP router directly or indirectly to ensure proper route propagation.
Step-by-Step Breakdown:
Logical Full Mesh:
In an IBGP setup, routers do not re-advertise routes learned from one IBGP peer to another IBGP peer. This rule is in place to prevent routing loops within the AS.
To ensure full route propagation, a logical full mesh is required, meaning every IBGP router must peer with every other IBGP router in the AS. This can be done either directly or via route reflection or confederation.
Physical Full Mesh Not Required:
The physical topology does not need to be a full mesh, but the BGP peering relationships must form a logical full mesh. Techniques like route reflectors or BGP confederations can reduce the need for manual full-mesh peering.
Juniper Reference:
IBGP Configuration: IBGP logical full mesh requirements can be simplified using route reflectors to avoid the complexity of manually configuring many IBGP peers.
Which route is preferred by the Junos OS software routing tables?
In Junos OS, direct routes are the most preferred routes in the routing table, having the highest priority.
Step-by-Step Breakdown:
Direct Routes:
Direct routes represent networks that are directly connected to the router's interfaces. Since these routes are directly accessible, they are assigned the highest priority and always take precedence over other types of routes.
Preference Values:
Direct routes have a preference of 0, which is the most preferred in Junos. Static routes, OSPF routes, and BGP routes have higher preference values and will only be used if there are no direct routes to the destination.
Juniper Reference:
Direct Route Preference: In Junos, direct routes are always preferred over other routes, ensuring that the router forwards traffic through locally connected networks.
