DDoS protection in cloud or on-premise: pros, cons, and the rise of hybrid defences
Distributed-Denial-of-Service attacks used to be the headache of large carriers and gaming giants. Today they reach everyone from small hosting firms to municipal websites. That change has pushed security teams to decide where DDoS filtering should live: in the cloud, on their own routers, or split between the two. This post walks through the practical trade-offs of each model and explains how FastNetMon lets you combine them.
What does ‘in the cloud’ mean in DDoS protection?
Cloud DDoS services sit upstream from your network. Traffic is routed (or permanently flows) through a provider’s scrubbing centres, where bad packets are filtered before the clean stream returns on a private tunnel or GRE connection.
Typical features:
- Terabit-scale bandwidth to soak up large floods
- 24 × 7 SOC teams who tune filters for you
- API hooks or web portals for manual triggers
- Always-on or on-demand routing options
When is the cloud the best option?
Off-network scrubbing is ideal when floods dwarf local links; a 10 Gbps circuit will not survive a 200 Gbps barrage, but a cloud service with terabits of headroom can soak it up invisibly. Providers also supply a 24 × 7 security operations centre, handy for teams that don’t keep engineers on call at 3 a.m. Because many platforms have worldwide points of presence, traffic can be filtered near the attacker and re-injected close to end users, trimming latency spikes for a global audience.
Where the cloud can fall short?
The detour that protects a site can hurt real-time services—voice, streaming and gaming users may notice the extra hop through distant scrub hubs. Costs can climb, too: pricing often hinges on the volume of “clean” traffic passed back after mitigation, meaning a busy retail launch might incur higher fees than the attack that triggered them. Adding cloud protection also introduces routing gymnastics with BGP fail-over, GRE tunnels or DNS cut-overs, any of which can misfire. Finally, data-residency rules in finance, healthcare or government may forbid traffic from leaving certain jurisdictions, limiting where cloud scrubbing is permissible.
What does ‘on-prem’ mean?
On-prem (or ‘inline’) systems run inside your own ASN – physical appliances, virtual machines, or containerised detectors talking straight to your routers.
Typical features:
- NetFlow, sFlow, or packet capture for sub-second detection
- BGP Remote Triggered Black Hole (RTBH) or Flow Spec for fast blocking
- Full control of detection thresholds and mitigation logic
When is on-prem an attractive option?
Keeping the scrubbing kit inside your own racks means packets never leave the network path, so latency stays low. Because the controls live on your hardware, you can enforce fine-grained policy—dropping, rate-limiting or redirecting only the prefixes and ports you choose. Data privacy is easier to guarantee when traffic remains under the same compliance umbrella, and a one-off capital purchase (or a fixed annual licence) brings predictable spend instead of open-ended clean-traffic fees.
Where on-prem struggles?
The model falters if an attack exceeds available transit: once links saturate, no appliance can restore capacity until extra bandwidth or upstream filtering is in place. It also demands round-the-clock vigilance; smaller teams must be ready to watch alerts, tune thresholds and push emergency routing changes at any hour.
Why are hybrid models becoming more prevalent?
A hybrid setup mixes local detection with cloud off-load. The on-prem system watches flows from the first packet, scrubs small to medium floods, and invokes cloud scrubbing only when a threshold (for example 80 % of link capacity) is crossed. This “autoscaling” limits cloud bills while protecting against the true headline attacks.
It also keeps latency in check for everyday traffic, because packets stay on-net unless a surge demands diversion. At the same time, operational teams keep a single view of both layers, making policy updates and post-incident reviews far simpler than juggling two isolated solutions.
How to choose the right mix?
- Measure baseline traffic – know your typical 95th percentile and peak spikes.
- Assess uplink limits – if the largest single circuit is 40 Gbps, plan for floods above that size to divert early.
- Factor response time – on-prem detection plus automated cloud API calls should move faster than manual ticketing.
- Plan your test days – schedule live drills, flushing prefixes through the scrubber and back, to confirm routing and application behaviour.
- Budget realistically – weigh capital spend on appliances against potential per-gigabit cloud costs during holiday peaks.
No single model fits every network
Latency-sensitive trading floors may lean local; SaaS providers with bursty traffic may lean cloud. For many operators, a hybrid design delivers the best of both worlds: on-prem agility for day-to-day events and cloud capacity for once-a-year floods.
FastNetMon’s platform was built with that blend in mind. It spots anomalies fast, applies the right filter in the right place, and hands control back to your team rather than locking protection into one vendor’s black-box. If you’re mapping out the next stage of your DDoS defence, take a closer look at how FastNetMon can help you stitch local and cloud layers into a single, responsive shield.
About FastNetMon
FastNetMon is a leading solution for network security, offering advanced DDoS detection and mitigation. With real-time analytics and rapid response capabilities, FastNetMon helps organisations protect their infrastructure from evolving cyber threats.
For more information, visit https://fastnetmon.com