Implementing Radware DefensePro DDoS Protection for Layer 7 Attacks

Application-layer DDoS attacks can look like legitimate customer activity while exhausting web servers, databases, connection pools, or API workers. An HTTP flood from a distributed botnet may use valid URLs, normal TCP sessions, and changing user agents, making simple firewall rules and bandwidth thresholds ineffective. Radware DefensePro can help identify this abnormal behaviour and enforce controls before application infrastructure is overwhelmed.

A successful deployment depends on traffic placement, accurate baselines, carefully staged policies, and close coordination with the web, network, and security teams. Australian organisations also need to account for geographically dispersed users, local carrier diversity, cloud connectivity, and operational requirements across locations such as Sydney, Melbourne, Brisbane and Perth.

Map The Protection Architecture

Start by documenting how public traffic reaches each protected service. Record DNS providers, authoritative IP ranges, internet carriers, cloud load balancers, reverse proxies, TLS termination points, and origin servers. DefensePro may be deployed inline at a data centre edge or used in an out-of-path design where suspicious traffic is diverted through the mitigation platform. The correct model depends on available interfaces, routing control, expected attack scale, and the licensed DefensePro features.

For an inline installation, connect the appliance between the upstream router or firewall and the protected network, using redundant links where possible. Confirm fail-open or fail-closed behaviour with the change board, because a hardware or power failure can have a different business impact under each option. In an Australian hosting environment, test failure paths through both major carriers rather than assuming that a single Sydney peering path represents all customer traffic.

Layer 7 protection may involve DefensePro behavioural detection alongside Radware AppWall or another web application security control. DefensePro is well suited to volumetric and protocol attacks, as well as behavioural identification of abnormal application traffic, while a dedicated web application firewall can address attacks such as SQL injection, cross-site scripting, and malicious HTTP requests. Define which device owns each control to prevent conflicting policies.

Establish A Reliable Traffic Baseline

Before enabling aggressive mitigation, collect normal traffic statistics for every application. Useful measurements include requests per second, concurrent connections, HTTP methods, response codes, URL frequency, source networks, TLS handshakes, average request size, and backend response time. A retail site may show sharp evening peaks, while a business portal may have predictable activity during Australian working hours.

Use several observation periods rather than a single quiet day. Include payroll runs, online promotions, month-end processing, school holiday traffic, and the end-of-financial-year period, when many Australian organisations experience unusual portal and reporting activity. Sydney and Melbourne traffic may dominate an application’s normal profile, but customer patterns from regional Queensland, Western Australia, and overseas should not be classified as anomalous simply because they are less common.

Export DefensePro events and counters to the existing monitoring platform through syslog, SNMP, or the supported API. Correlate mitigation events with load balancer metrics, web server logs, database connections, and cloud service alarms. A rise in HTTP 503 responses without a corresponding increase in inbound requests may indicate an application failure rather than a DDoS event.

Configure Behavioural Detection Carefully

Create protection policies for each service or service group instead of applying one universal threshold. Set expected limits for connections, request rates, connection duration, and resource consumption, then tune them against the baseline. Layer 7 attacks often stay below a simple packets-per-second threshold, so detection should consider request behaviour, repeated URL access, incomplete sessions, and sudden changes in client distribution.

Use rate controls and signatures selectively. Controls for excessive HTTP requests, abnormal connection persistence, malformed requests, and suspicious protocol behaviour can reduce pressure on origin systems. Where supported, challenge or block suspicious clients progressively rather than immediately dropping all traffic from a shared carrier or cloud network. Excessively broad blocking can affect legitimate users behind carrier-grade NAT, a common situation for Australian broadband and mobile customers.

TLS requires special planning. If DefensePro cannot inspect encrypted application content at the chosen traffic position, it can still provide valuable network and connection-level mitigation, but it will not see URLs, headers, or application payloads. Place inspection after an approved TLS termination point or integrate the policy with the organisation’s reverse proxy and load-balancing design. Protect private keys, document ownership, and verify that certificate renewal procedures remain unaffected.

Test Mitigation Without Disrupting Users

Validate the policy in a monitoring or learning mode before enforcing it. Generate controlled requests from approved test systems and confirm that normal browsers, mobile clients, API consumers, health checks, and monitoring probes are recognised correctly. Do not use an unapproved public stress-testing service against production systems; arrange a controlled test with the carrier, hosting provider, and security team.

Test more than a high-volume HTTP flood. Include slow connections, repeated expensive URLs, large numbers of short-lived sessions, abnormal HTTP methods, cache-bypass requests, and bursts distributed across many source addresses. Check whether the mitigation protects the origin or merely shifts the bottleneck to the firewall, TLS proxy, load balancer, or database.

For organisations operating across Australia, test failover between data centres or cloud regions, such as Sydney and Melbourne, and verify the effect on customers connecting through Brisbane, Perth, and external Asia-Pacific networks. Confirm BGP advertisements, DNS changes, health checks, and return routing. Record the expected recovery time and ensure the service desk has a plain-language message for customers during a mitigation event.

Operate And Tune The Service

During an incident, examine the protected service, attack category, top URLs, source distribution, request rate, and mitigation action. Compare DefensePro telemetry with origin CPU, memory, worker pools, database load, and application response times. This helps distinguish an HTTP flood from a genuine product launch, a broken client integration, or a sudden indexing event.

Maintain an incident runbook covering escalation contacts, carrier diversion, DNS changes, evidence collection, and rollback steps. Australian teams should include local internet service providers, managed security partners, cloud vendors, and contacts responsible for Australian Privacy Act obligations where logs contain personal information. Keep time synchronisation consistent so appliance events can be matched accurately with application and carrier records.

Review policies after every significant event. Tune thresholds using observed customer behaviour, remove temporary exceptions, and check that firmware, signatures, licences, and threat intelligence feeds are current. Schedule routine configuration backups and restore tests, particularly before planned maintenance or seasonal peaks. With disciplined baselining and operational ownership, DefensePro becomes part of a broader DDoS resilience design rather than a device that is only examined when an outage has already begun.