CCNP Advanced Enterprise 350-401 ENCOR Part1/2

Explore how switches build and use the 48-bit MAC address table, learn addresses dynamically, age them out after five minutes, and configure static entries to stabilize forwarding.

Demonstrate how the forwarding information base mirrors the routing table, compare hardware and software tables, and introduce the GNC table for rapid layer two and three forwarding.

Explore network redundancy and high availability by implementing first hop redundancy protocol, using virtual IP and virtual MAC to keep gateways up when a device fails.

Explore Cisco proprietary hsrp, the hot standby router protocol, including version 1 and 2, active and standby roles, virtual ip and mac ownership, group numbers, and halo timers for failover.

Explore how interface tracking in HSRP switches the active router by monitoring an outside interface, using track objects and priority decrement, enabling preemption to restore the active role.

Understand how VRRP, an open standard, provides high availability with a master and backup, a virtual IP and MAC, using multicast hello for elections across IPv4 and IPv6 networks.

Explore HSRP load sharing theory, using two groups and two virtual gateways (253 and 254) to activate switches alternately, enabling load shedding and seamless failover for multiple gateways.

Explore dynamic trunking protocol (DTP) and the Cisco proprietary negotiation that auto-creates trunk links, including dynamic auto, dynamic desirable, trunk, and no negotiation for static setups.

Explains how VLAN hopping exploits trunk negotiation to turn an access port into a trunk. Shows how to prevent it by disabling DTP on access ports and enforcing no negotiation.

Explore ether channel concepts to combine multiple interfaces into a single port channel, boosting bandwidth and availability with lacp, pagp, or manual mode.

Explore three ether channel protocols: LACP, PAgP, and static, and how active and passive roles determine success, including active–active versus passive–passive outcomes.

Configure lacp in a lab to create layer 2 and layer 3 ether channels across distributed and access switches, using port channels 20 and 2 with active and passive modes.

Configure a PAgP lab across distributed and access switches to form layer two and layer three port channels 10 and 3 with dot1Q encapsulation, BGP, and IGP.

Learn how ether channel load balancing uses hash algorithms based on source and destination MAC/IP addresses (and ports) to distribute traffic across two, four, or eight links, not equally.

The EtherChannel misconfiguration guard detects channel parameter mismatches and places misconfigured interfaces into error-disabled state, with a configurable recovery interval.

Learn how to use switch port analyzer (span) to monitor traffic, diverting it to firewalls, with local span, remote span, and erspan, plus session IDs and capture options.

Explore spanning tree protocols—stp, pvst+, rapid pvst+, mst—and how they prevent layer 2 loops, enable redundancy, and maintain availability via bpdu exchanges and route bridge decisions.

Learn why the spanning tree protocol prevents layer two loops by blocking redundant links, ensuring availability through backup paths, and faster convergence with rapid STP.

Explore how STP selects the root bridge using default bridge priority 32768 and MAC address as tie-breakers, and how port priority and port cost determine blocking and forwarding.

Explain how STP selects a root bridge, then a root port and a designated port, using cost, priority, and port number as tie breakers.

Explore spanning tree protocol port roles—root port, designated port, and alternate port—and learn how they reach the root bridge and forward or block traffic.

Explore STP port states, including blocking, listening, learning, and forwarding, and how designated and non-designated ports prevent loops, with 15-second listening and learning transitions and bpdu forwarding.

Learn how bridge protocol data units drive spanning tree by exchanging configuration, topology change notifications, and acknowledgments every two seconds to elect the root bridge, root port, and designated ports.

Explore how spanning tree protocol operates across a four-switch topology, configuring trunks, svIs, and vlans, then verify root bridges, root ports, and designated ports using pvst metrics.

Explore spanning tree protocols in a lab by configuring root bridges via priority and cost, and adjusting VLAN configurations, port priority, and port-first edge mode to speed convergence.

Explore spanning tree timers including hello timer, forwarding delay, and maximum age, and learn how to view, modify, and compare these values and associated bpdu information on a switch.

Rapid spanning tree protocol speeds up convergence and stability over stp by using discarding port states, route/designated/alternate/backup ports, and version two bpdu timing for quick transitions to forwarding.

Explain how MST maps VLANs into multiple STP instances within an MST region, reducing switch burden and maintenance compared with common and pavilion spanning trees.

In this MSTP lab, configure multiple spanning tree on a shared topology using MST, create extra VLANs, map them to MST instances, enable MST, and verify with show commands.

Explore routing fundamentals, including static and dynamic routing, routed versus routing protocols, and how routers build routing tables using metrics, administrative distance, and prefix length to reach destinations.

explain how administrative distance from 0 to 255 decides the best route and how metrics like hop count or bandwidth influence path choice.

Explore static routing types, directly attached, recursive, fully specified, and null routes, through a hands-on lab that verifies reachability using show run, ip route, and ping.

Explore floating static routes in a three-router lab, using a primary and backup path, testing with icmp, and analyzing per destination versus per packet load balancing.

Explore how ARP translates IP addresses to MAC addresses, builds the ARP mapping table, and uses aging and group status ARP, permanent entries, and proxy ARP to enable network communication.

This lecture demonstrates how inter-subnet traffic flows from PC1 to PC2 through routers, highlighting ARP requests, gateway MAC learning, and MAC address rewriting at each hop to forward packets.

Routers use the longest prefix match from the routing table to select the best path. When lengths tie, administrative distance and metric decide route, enabling load sharing and load balancing.

Explore how EIGRP maintains neighbor, topology, and routing tables, including learned neighbors, successors, and how best routes are installed and load balanced.

Explore the five EIGRP packet types—hello, update, acknowledgement, query, and reply—and how they establish neighbors, advertise routes, and ensure reliable updates, queries, and replies.

Learn how EIGRP path optimization works by adjusting bandwidth and delay to influence metrics, selecting the best route, and using topology and routing tables to compare multiple paths.

Explains ip routing terminologies in eigrp, including advertised distance, reported distance, and feasible distance. Shows how successor and feasible successor determine routing choices and the feasibility condition.

Explore EIGRP summarization theory, compare automatic and manual summarization, and show how summarization reduces routing table size, memory, bandwidth, and CPU usage while boosting stability.

Explore eigrp summarization techniques in a lab with r4 and r5, comparing auto and manual summaries, disabling auto summary, and using null interface routes for efficient routing.

Explore EIGRP equal-cost load balancing with identical path metrics and dual routes, and learn to apply variance and feasible distance to enable unequal load balancing.

Explore open shortest path first, a link-state dynamic routing protocol that builds a complete network topology map, uses area zero backbone, and applies the shortest-path first algorithm.

Learn core OSPF terminologies, including area zero backbone, non-backbone areas, ABR and DR/BDR roles, router IDs, link-state advertisements and databases, and how areas connect through the backbone to optimize routing.

Configure ospf in a multi-area topology, advertising loopback and backbone networks across area zero, area one, and area two to ensure pc1 reaches pc2.

Understand how OSPF metric calculation uses cost, defined as reference bandwidth divided by interface bandwidth, to determine routes and how changing the reference bandwidth affects costs and load balancing.

Explore the OSPF header and the five packet types—hello, database description, link state request, update, and acknowledgement—plus key header fields, shown with Wireshark captures.

Assign a unique 32-bit OSPF router ID to avoid duplicate IDs; manually set it, otherwise use the highest loopback IP, or the highest active interface IP if no loopback exists.

Identify OSPF route types in the routing table, including intra-area routes within area zero, inter-area routes from other areas, and external routes redistributed from other protocols, plus the default route.

OSPF elects a designated router and backup designated router in a broadcast domain to distribute updates, using router priority and router ID, with no preemption.

Learn how OSPF performs equal cost load balancing by default, supporting up to four equal-cost paths; verify with show ip route ospf and traceroute, and adjust with the maximum path command.

Learn to summarize OSPF routes using area range on an ABR to reduce routing table size, and apply summary address for external routes redistributed into OSPF.

Block OSPF updates on selected interfaces by enabling passive interfaces to stop hello packets, preventing topology exposure on edge and ISP links for added security.

Explore OSPF network types—point-to-point, broadcast, non-broadcast, and point-to-multipoint—highlighting how hello and dead timers, neighbor discovery, and DR/BDR election vary by network type.

Explore OSPF network types through hands-on labs: point-to-point, broadcast, non-broadcast, and point-to-multipoint topologies, including DR/BDR roles, hello timing, static neighbors, and multicast hello via 224.0.0.5.