Juniper JNCIS-ENT - JN0-351 - Complete Course

Examine forwarding loops and broadcast storms in layer 2 networks and how spanning tree protocols create a loop-free topology via root bridge election, bpdus, and port roles.

Explore the original 802.1D spanning tree protocol, including BPDU exchanges, root and designated ports, and port states, and examine slow convergence and topology change handling.

Explore rapid spanning tree protocol and its faster convergence over classic spanning tree protocol, including edge ports, alternate and backup ports, discarding state, and rapid root port transitions.

Configure and monitor stp and rstp on Junos devices, use force version stp for 802.1d, and read root bridge, designated and root ports via show spanning tree.

Explore BPDU protection, loop protection, and root protection within spanning tree, preventing rogue switches and unidirectional links while configuring protections to block BPDUs and maintain network stability.

Demonstrates rapid spanning tree protocol configuration and monitoring across two switches to prevent loops, validate connectivity, and observe topology convergence.

Learn how Ethernet ring protection switching enables fast, loop-free ring topologies with a 50 ms convergence time, using a ring protection link and owner control to restore continuity.

Master layer two security by implementing mac limiting, mac move limiting, and persistent mac learning to prevent bridge table overflows, reduce spoofing risks, and improve switch resilience.

Explore dhcp snooping, dynamic arp inspection, and ip source guard to strengthen layer two security, prevent arp poisoning and rogue dhcp servers, and protect enterprise switching.

Learn storm control to mitigate broadcast storms on Junos devices and enable automatic recovery. Understand stateless layer two firewall filters, with from-then terms guiding ingress and egress actions.

Explore layer 2 security with hands-on configuration of DHCP security, Dynamic ARP inspection, and layer 2 firewall filters to mitigate rogue DHCP servers and ARP spoofing.

Analyze static, aggregate, and generated routes in Junos to understand protocol independent routing while noting next-hop reachability, aggregate summarization, and that generated routes use a real next hop.

Explore martian addresses in Junos, review default IPv4 and IPv6 ranges defined by RFC 1208 and RFC 3330, and learn how to view and manage martian routes.

Learn to use routing instances and rib groups in Junos to separate and selectively share routing information between instances, with examples of default and non-default instances and import/export concepts.

Explore layer three load balancing in Junos, using equal cost multipathing to distribute traffic across multiple links through per packet or per flow methods, configured via routing and export policies.

Explore filter based forwarding in Junos, using firewall filters to match traffic and direct it to a dedicated forwarding routing instance for customized routing decisions, akin to policy based routing.

Explore protocol independent routing in junos with a hands-on lab that configures static routes, aggregate routes, routing instances, and rib groups across Vsx devices and loopback connectivity.

Explore OSPF as a link-state IGP, examine how the link-state database is built and kept identical across routers in an area, and understand how LSAs flood to enable scalable routing.

Explain how OSPF neighbor formation builds adjacencies by exchanging hello packets, matching fields, and progressing from two-way to full adjacency with DBD exchanges and LSDB synchronization.

Learn how OSPF assigns a designated router and backup designated router on broadcast segments, how priority and router IDs determine the election, and how they flood LSAs to others.

Explore ospf area and router types, including abr, asbr, and dr/bdr, backbone area zero, and stub, total stub, and not so stubby areas, with lsa types and interarea routing.

Explore OSPF LSA types and area realms, detailing router LSA, network LSA, summary LSA, external and NSA concepts, and explain ABR and ASBR roles and flooding rules.

Configure and troubleshoot multi-area OSPF in Junos, acting as an ABR and ASBR by redistributing a static route, monitoring neighbors, interface participation, and OSPF database in a hands-on lab.

Explore the IS-IS overview as a link-state interior gateway protocol based on SPF, covering areas, level one and two routers, backbone design, and PDU TLV exchange, with comparisons to OSPF.

Explore the IS-IS PDU types IIH, LSP, KSNP, and SNP, and their TLVs, detailing how they establish adjacency, flood topology, and synchronize the lsdb.

Explore ISIS neighbor formation, including initialization and up states, and how PDUs, CSPs, and LSPs establish full adjacency. Note DS elections and priority-based selection for level one and two adjacencies.

Explore how multi level and multi area IS-IS uses level one and level two routers, area lsdbs, and controlled LSP flooding with default routes to the nearest level two router.

Configure IS-IS on Junos by setting the loopback ISO address, enabling the ISO family on participating interfaces, and defining level one adjacencies with packet-based forwarding.

Learn to monitor and troubleshoot ISIS on Junos with commands to validate interfaces, adjacencies, LSP database contents, and ISIS PDU statistics.

Learn to configure, monitor, and troubleshoot multi-area IS-IS in Junos, including L1/L2 adjacencies, area 51 and 52, default routes, and trace-based error diagnosis.

Explore BGP, the routing protocol of the internet, an exterior gateway protocol that exchanges routing information between autonomous systems using path vector attributes.

Explore the four BGP message types—open, update, keepalive, and notification—and how they support peering and routing information exchange. Understand the common BGP header, including marker, length, and type fields.

Learn the BGP neighbor state machine from idle to established, including TCP port 179 handshakes, open messages, keepalives, and transitions through active, notification, and teardown.

Explore how BGP selects the best path by examining route attributes, their classifications (transitive vs nontransitive, mandatory vs discretionary, well known vs optional), and the stepwise path selection algorithm.

Compare iBGP and eBGP, focusing on loop avoidance and the full-mesh requirement. Master next-hop self, as-path loop protection, loopback peering, TTL and multi-hop configuration.

Configure and monitor internal and external BGP in Junos, apply export policies and next-hop self, and use route aggregation to influence advertisements and verify with show commands.

Master BGP configuration, monitoring, and troubleshooting in a Junos lab, including iBGP and multi-ISP peering. Implement advertise inactive, as path prepending, and next-hop self to ensure 8.8.8.8 reachability.

Explore ip tunnel concepts and configurations in Junos, including ip in ip and GRE tunnels, their stateless behavior, and key considerations for mtu, fragmentation, and routing.

Learn GRE tunnels in Junos, including GRE encapsulation within IPv4, the GRE header and extended GRE fields, and basic GRE tunnel configuration on Junos routers.

Master ip-in-ip tunnels in junos, a simplified gre-like mechanism that encapsulates ipv4 packets in an outer ipv4 header with inner headers and no tunnel header.

Define high availability and its uptime and downtime measures in networks. Learn Junos features that boost availability, including grs, nsr, nsb, bfd, vrrp, issu, lag, rtg, and vc.

Enable GRES, NSR, NSB, and ISSU on Junos devices to minimize production traffic impact by synchronizing control plane state across redundant routing engines.

Explore link aggregation groups (lags) and redundant trunk groups (rtgs) and their IEEE 802.3ad, LACP negotiation, configuration, and how load balancing and high availability are achieved in Junos.

Explore Junos virtual chassis concepts, including dynamic and pre-provisioned member configurations, vcpus, member IDs, and single management access, plus NSU and traffic flow optimization.