This blog will guide you through **failover testing on ASA Post-9.7** by explaining the modern approach, configurations, and validation steps.
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### What's Changed in ASA Post-9.7?
ASA firmware 9.7 introduced several enhancements to the failover process, including:
- **Stateful Failover Improvements:** Failover is more seamless, preserving more session data, including certain stateful connections like VPN, to minimize disruptions.
- **Failover Performance Monitoring (FPM):** Introduced to monitor active failover performance, it gives administrators deeper insights into failover readiness.
- **Enhanced Inspection Engines:** Beyond simple ICMP inspections, stateful inspections for a variety of protocols are now more efficient, improving traffic continuity during failover.
These features improve reliability and performance during failover scenarios, but it's crucial to properly test the setup.
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### Prerequisites for Modern Failover Testing
Before conducting a failover test, ensure that you meet the following prerequisites:
1. **Correct Failover Configuration:** Primary and Secondary ASAs must be properly configured with both LAN failover and Stateful failover interfaces.
2. **ICMP Inspection Enabled:** Enable ICMP inspection (though Post-9.7 ASA has enhanced protocol inspections, ICMP remains a lightweight, effective way to test connectivity during failover).
3. **Monitoring & Alerts:** Enable failover monitoring with SNMP traps or syslog to track failover events in real-time.
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### Failover Test: Step-by-Step Guide
Here is how you can test ASA failover post-9.7, ensuring a more advanced and detailed validation of your high-availability setup:
#### 1. **Configure Stateful Failover**
Ensure stateful failover is enabled on both the primary and secondary ASAs.
failover
failover lan unit primary
failover lan interface LANFAIL GigabitEthernet0/3
failover link STATEFULFAIL GigabitEthernet0/4
failover interface ip LANFAIL 192.168.1.1 255.255.255.0 standby 192.168.1.2
failover interface ip STATEFULFAIL 192.168.2.1 255.255.255.0 standby 192.168.2.2
failover key *****
This ensures that the state information for connections is transferred from the active to the standby ASA.
#### 2. **Enable ICMP Inspection**
Enabling ICMP inspection helps you test connectivity between two routers (R1 and R2) across the ASAs. However, if your test involves other protocols (HTTP, TCP, etc.), make sure their respective inspections are enabled.
policy-map global_policy
class inspection_default
inspect icmp
#### 3. **Start Continuous Ping**
Initiate a continuous ping from R1 (inside the network) to R2 (outside the network). This will give you a simple but reliable way to monitor failover functionality.
On **R1**:
ping 192.168.2.10 -t
This will keep pinging R2 to track any loss of connectivity.
#### 4. **Trigger Failover**
Force a manual failover to switch from the active ASA to the standby ASA.
On the **Primary ASA** (Active):
no failover active
Alternatively, if you want to simulate hardware failure or network disconnection, you can disconnect the interface cables from the active ASA.
#### 5. **Verify Failover & Connectivity**
**a. Checking Failover Status**
On the newly Active ASA (previously Standby), run the following commands to verify that the failover has occurred and the system is operating normally:
show failover
Example output:
Failover On
Active time: 5 minutes
This host: Primary - Standby Ready
Other host: Secondary - Active
You can also use:
show failover state
show failover history
These commands give insights into how the failover occurred, the current status of both units, and any state replication issues.
**b. Verifying Connection State:**
Post-9.7, ASA improves stateful failover, so you should experience **minimal to no packet loss** during the failover event. While the failover occurs, monitor the pings running from R1 to R2. There may be a single packet loss, but connectivity should immediately resume.
**c. Reviewing Logs:**
Check syslogs or SNMP traps for failover events:
show log | include failover
This will provide you with detailed information about the failover event.
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### Failover Testing Best Practices Post-9.7
1. **Minimal Downtime Expectations:** With enhanced stateful failover and FPM monitoring, expect very minimal downtime. A single dropped ping is typically the worst-case scenario.
2. **Use Various Protocols:** ICMP is a great initial test, but for a comprehensive failover validation, ensure that you test multiple protocols (e.g., TCP, HTTP, FTP). ASA now better handles these transitions.
3. **Monitor Failover Events:** Utilize SNMP or syslog alerts to monitor real-time failover events and ensure proper transitions. Post-9.7 introduces better tracking and alerting mechanisms.
4. **Scheduled Failover Tests:** It's important to schedule routine failover tests to ensure high availability and the health of both active and standby units.
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### Conclusion
Failover testing on ASA Post-9.7 is a more robust and efficient process, thanks to improvements in stateful failover and monitoring. With minimal packet loss during failover, organizations can ensure business continuity even during critical infrastructure transitions. Following the steps and best practices outlined above will help you thoroughly validate your failover configuration and ensure that your ASA devices are properly securing and managing your network.
By performing routine tests and utilizing the enhanced features, you can be confident that your failover setup will operate as expected when it matters most.
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