Dell Networking Associate (D-NWG-FN-23) flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

OSI Layer 2

The Data Link layer; switches forward Ethernet frames using MAC addresses within a broadcast domain. VLANs, STP, and link aggregation operate here.

TCP three-way handshake

Connection setup using SYN, SYN-ACK, then ACK. It synchronizes sequence numbers and confirms bidirectional reachability before data transfer begins.

Private IPv4 ranges

10.0.0.0/8, 172.16.0.0/12, and 192.168.0.0/16 are non-routable on the internet and require NAT for external connectivity.

ARP function

Address Resolution Protocol maps a known IPv4 address to a MAC address within the local broadcast domain by broadcasting a request and caching the reply.

Usable hosts formula

For a subnet with h host bits, usable addresses equal 2^h minus 2, subtracting the network and broadcast addresses. A /24 yields 254 usable hosts.

Dell PowerSwitch N-series

Campus and branch access switches, typically 1GbE with PoE options, running Dell Networking OS9. Positioned for wiring closet and user access deployments.

Dell PowerSwitch Z-series

High-density 100GbE and 400GbE spine and aggregation platforms running OS10, positioned for leaf-spine data center fabrics and high-bandwidth core roles.

Dell Networking OS10

Linux-based network operating system for S-series, Z-series, and newer PowerSwitches. Supports VXLAN, EVPN, VLT, REST API, and a candidate-config commit model.

SmartFabric Services

Dell OS10 automation feature that provisions underlay, overlay, and VLAN-to-VNI mappings across a switch fabric from a single fabric definition.

802.1Q VLAN tag

A 4-byte tag inserted after the source MAC containing a 12-bit VLAN ID. Trunk ports carry multiple tagged VLANs; the native VLAN is sent untagged.

RSTP port roles

Rapid Spanning Tree defines root, designated, alternate, and backup roles with discarding, learning, and forwarding states, converging faster than 802.1D STP.

VLT concept

Dell Virtual Link Trunking pairs two switches into one logical L2 domain using a VLT interconnect and backup link, enabling active-active multipathing without STP blocking.

LACP negotiation

IEEE 802.3ad Link Aggregation Control Protocol negotiates bundled links. Member ports must match speed, duplex, and VLAN settings to join the bundle.

BPDU Guard

A switch feature that err-disables an edge port if it receives a spanning-tree BPDU, preventing unauthorized switches from affecting the topology.

Administrative distance

A ranking of route sources used when multiple protocols offer the same prefix. Lower is preferred; connected is 0, static 1, eBGP 20, OSPF 110.

OSPF DR/BDR election

On multi-access segments OSPF elects a Designated Router and Backup by highest priority then highest router ID, reducing adjacency count and LSA flooding.

BGP best path order

BGP selects by weight, then local preference, then shortest AS-path, then origin, then MED, then eBGP over iBGP, then lowest router ID.

VRRP master role

The VRRP router holding the virtual IP and virtual MAC answers ARP and forwards traffic for the group; a backup takes over if hellos stop.

ECMP routing

Equal-Cost Multi-Path installs multiple next hops for the same prefix and load-shares traffic across them, typically using a 5-tuple hash.

DHCP relay helper

The 'ip helper-address' command forwards client DHCP broadcasts as unicast to a server on another subnet, enabling centralized DHCP across VLANs.

Leaf-spine topology

A data center fabric where every leaf connects to every spine. Spines route between leaves using ECMP, giving predictable one-hop east-west latency.

VXLAN VNI

A 24-bit VXLAN Network Identifier identifying an overlay segment, supporting roughly 16 million segments. Frames are encapsulated in UDP port 4789.

BGP EVPN route type 2

The MAC/IP advertisement route distributes host MAC and IP reachability between VTEPs, enabling control-plane learning and ARP suppression in VXLAN fabrics.

Anycast VTEP

Multiple leaf switches share one VTEP IP address, so any leaf can decapsulate traffic for a host behind it, simplifying multi-homing in the fabric.

VXLAN MTU requirement

Encapsulation adds roughly 50 bytes, so the underlay MTU must be at least 1600 bytes, commonly set to 9216 jumbo frames, to avoid fragmentation.

Port security violation modes

Protect drops offending frames silently, restrict drops and logs, and shutdown err-disables the port. Sticky MACs persist learned addresses across reloads.

802.1X roles

The supplicant is the client, the authenticator is the switch port, and the authentication server is RADIUS. EAP carries credentials between them.

DHCP snooping

A feature that trusts only designated uplink ports for DHCP server replies and builds a binding table used by IP Source Guard and Dynamic ARP Inspection.

TACACS+ versus RADIUS

TACACS+ uses TCP 49 and encrypts the full payload for device administration; RADIUS uses UDP 1812/1813 and encrypts only the password, suited to network access.

SNMPv3 security

SNMPv3 adds authentication using MD5 or SHA and privacy using DES or AES, replacing plaintext community strings used in SNMPv1 and v2c.

RESTCONF protocol

A model-driven HTTP-based interface using GET, POST, PUT, PATCH, and DELETE against YANG-modeled data, commonly used to automate Dell OS10 switches.

OSPF stuck in EXSTART

An OSPF neighbor stuck in EXSTART or EXCHANGE typically indicates an MTU mismatch between the two interfaces, preventing database description exchange.