- public IP: 4-30 minutes adjustable inbound, 4 minutes fixed outbound.
- LB: adjustable, 4-100 minutes. Default is 4 minutes.
If you set idle timeout to a large value, you risk reaching the VM connection limit. On the other hand, a very short idle time out could drop valid connections.
For SSH, Azure recommends ClientAliveInterval 180 (30-235 if there are special requirements), corresponding to 75% of default idle timeout.
References
- https://learn.microsoft.com/en-us/azure/load-balancer/load-balancer-tcp-idle-timeout
- https://learn.microsoft.com/en-us/azure/virtual-network/ip-services/public-ip-addresses
- https://learn.microsoft.com/en-us/azure/virtual-machines/linux/redhat-create-upload-vhd
- https://learn.microsoft.com/en-us/partner-center/marketplace/azure-vm-certification-faq