i create generic host (Firewall) server and virtual server for wide ip,
i use health monitor is gateway_icmp but server and virtual server It keeps flapping between up and down, and the status is unstable.
i was cli device F5 ping test to device generic host ok, its ok, its dont have lost or packet loss
can you help me check issue
The flapping you’re seeing with GTM Wide IP using a gateway_icmp monitor is usually because GTM health checks behave differently from manual ping—factors like aggressive default intervals, multiple GTM devices probing inconsistently, firewall ICMP rate-limiting, or source IP differences can cause intermittent failures even when basic connectivity looks fine; since ICMP only checks reachability (not service health), it’s often unstable for this use case, so tuning the monitor or switching to a more reliable protocol-based check is the recommended approach.
few other Solutions to explore further:
1. Tune ICMP monitor: Increase interval/timeout to reduce sensitivity and avoid false downs.
2. Use TCP monitor: Check a port (e.g., 443) for more stable and meaningful health status.
3. Use HTTP/HTTPS monitor: Validate actual application response instead of just reachability.
4. Adjust quorum (multi-GTM): Prevent a single failing probe from flipping overall status.
5. Check firewall policy: Ensure ICMP from GTM is not rate-limited or blocked intermittently.
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Is there any possibility of using TCP monitor instead of ICMP, as TCP is minimum best for firewalls
If behind firewall:
Use HTTP/HTTPS monitor (if applicable)
Can you check and tell:
Is ICMP rate-limited?
Is GTM self-IP allowed?
Any IPS/DoS protection?
Avoid gateway_icmp for Wide IP health checks
its better to use
TCP monitor (minimum)
HTTP/HTTPS monitor (ideal)
If you want, share:
Your GTM topology (single / HA / multi-site)
Monitor config output (tmsh list ltm monitor)
tmsh show gtm server
I can dig further and will try to pinpoint the exact root cause in your setup.