OCI 1Z0-1124-25 Glossary: Key Terms
March 31, 2026
OCI 1Z0-1124-25 glossary of VCNs, subnets, routing, DRG connectivity, and hybrid design terms.
Use this glossary to clean up high-confusion OCI networking terms before you go back into mixed sets. On this exam, vocabulary mistakes usually hide a path, filter, or boundary mistake.
High-value terms
| Term |
What it means here |
Why it matters on the exam |
| DNS |
name-resolution layer used to map names to destinations |
DNS is a common tie-break in troubleshooting order |
| DRG |
OCI’s private-routing hub for network attachments |
DRG often anchors hybrid and multi-network questions |
| East-west traffic |
internal traffic moving between private services or tiers |
this is different from internet-edge exposure |
| FastConnect |
dedicated private connectivity between OCI and external networks |
common tie-break against VPN |
| Internet gateway |
VCN attachment that provides a path to the public internet |
it answers public-path questions, not all connectivity questions |
| Load balancer |
service that distributes incoming traffic across targets |
often confused with lower-layer NLB choices |
| Network firewall |
inspection and policy-enforcement layer for network traffic |
this is about inspection and control, not just next-hop routing |
| NLB |
Network Load Balancer with lower-layer traffic distribution behavior |
not the same fit as the classic load balancer |
| Route table |
rule set that decides where subnet traffic goes next |
a route does not permit traffic by itself |
| VCN |
OCI’s private network boundary |
many questions hinge on what belongs inside this boundary |
Common confusion pairs
| Pair |
Clean separation |
| Internet gateway vs FastConnect |
internet gateway exposes a public path, FastConnect provides private dedicated connectivity |
| Load balancer vs network load balancer |
the classic load balancer and NLB distribute traffic differently and fit different layers |
| Routing vs filtering |
routing decides where traffic goes, filtering decides which traffic is allowed |
| DNS decision vs route-table decision |
DNS resolves names, route tables determine packet next-hop behavior |
| Public edge vs east-west path |
public edge handles ingress or egress exposure, east-west paths connect internal tiers |
| NAT gateway vs service gateway |
NAT handles outbound internet for private subnets, service gateway reaches Oracle services privately |
| DRG vs gateway-at-the-edge |
DRG is a private-routing hub, edge gateways serve more specific boundary crossings |
Fast recall anchors
| If you see… |
Think… |
| next hop |
route table or gateway |
| allow or deny |
NSG or security list |
| private hybrid reachability |
DRG, VPN, or FastConnect |
| name mismatch or wrong endpoint |
DNS |
If three terms blur together
| Terms |
Short reset |
| route table, NSG, security list |
route table chooses path, NSGs and security lists permit or deny traffic |
| internet gateway, NAT gateway, service gateway |
internet gateway is public edge, NAT is private-subnet outbound internet, service gateway is private access to Oracle services |
| DRG, VPN, FastConnect |
DRG is the private hub, VPN and FastConnect are path types that attach into broader connectivity design |
| load balancer, NLB, network firewall |
load balancers distribute traffic, network firewall inspects and enforces policy |
Route misses well
| If you missed because… |
Go next |
| you mixed up path and filter roles |
FAQ |
| you need fast network tie-breaks |
Cheat Sheet |
| you need a paced rebuild of the weak lane |
Study Plan |
| you need the official Oracle or OCI source |
Resources |
Revised on Monday, June 15, 2026