JNCIP-ENT JN0-649 Juniper Study Notes

"Secondary interfaces are supported for LAN interfaces (the primary interface can be a LAN interface, but any secondary interfaces are treated as point-to-point unnumbered links over the LAN). In this scenario, you must ensure that there are only two routing devices on the LAN or that there are only two routing devices on the LAN that have secondary interfaces configured for a specific OSPF area." [https://www.juniper.net/documentation/us/en/software/junos/ospf/topics/topic-map/configuring-ospf-areas.html#id-example-configuring-multiarea-adjacency-for-ospf]

LLDP-MED (Link Layer Discovery Protocol-Media Endpoint Discovery) is an extension of LLDP (Link Layer Discovery Protocol) that provides additional functionalities specifically for voice over IP (VoIP) devices, including automatic negotiation of power requirements. This protocol is essential for automatically negotiating power with IP phones when they are connected to EX Series switches.

Steps:

Enable LLDP-MED:

set protocols lldp-med

Configure LLDP-MED on the interfaces:

set interfaces ge-0/0/0 unit 0 family ethernet-switching port-mode access

set interfaces ge-0/0/0 unit 0 family ethernet-switching interface-mode access

set interfaces ge-0/0/0 unit 0 family ethernet-switching vlan members default

set interfaces ge-0/0/0 unit 0 family ethernet-switching storm-control default

Commit the configuration:

References:

Useful Juniper Commands.txt

Tech Ops Managed Router Juniper Install Guide

Understanding Multicast Listener Registration Protocols:

Multicast listener registration protocols are used to manage multicast group memberships on a network.

They allow devices to join or leave multicast groups dynamically.

Protocols Supported by Junos:

MLD (Multicast Listener Discovery):

Used for IPv6 multicast group management. It is the IPv6 equivalent of IGMP.

MLD allows routers to discover multicast listeners on a network.

IGMP (Internet Group Management Protocol):

Used for IPv4 multicast group management.

IGMP enables hosts to join and leave multicast groups and allows routers to manage multicast group memberships.

Verification and Configuration in Junos:

MLD and IGMP are supported on Juniper devices running the Junos operating system.

Configuration examples:

IGMP:

shell

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set protocols igmp interface ge-0/0/1.0

MLD:

shell

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set protocols mld interface ge-0/0/1.0

References:

Juniper IGMP Configuration Guide

Juniper MLD Configuration Guide

When troubleshooting an EVPN-VXLAN IP fabric loop, the following steps are crucial:

Issue the show route table bgp.evpn.0 command on Leaf2 and verify that Type 4 routes are present: Type 4 routes indicate EVPN Ethernet Segment routes, which are essential for detecting and mitigating loops.

Issue the show route table bgp.evpn.0 command on Leaf2 and verify that Type 3 routes are present: Type 3 routes (Inclusive Multicast Ethernet Tag routes) ensure that multicast and broadcast traffic is properly handled, helping identify and troubleshoot loop issues.

References:

The commands for verifying BGP EVPN routes are standard in troubleshooting EVPN-VXLAN fabrics.

Documentation from "Useful Juniper Commands.txt" and "Juniper Commands.pdf" which provide command references for verifying EVPN route types​​​​.