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Can't connect to VM with my Bastion Host

Vidya Jatheesh 5 Reputation points
2026-02-24T05:24:30.5733333+00:00

My Bastion host connection stopped wokring today to all my VM.

I get this message: An internal error has occurred within the Bastion Host, and the connection has been terminated. If the problem persists, please contact support.

Azure Bastion
Azure Bastion

An Azure service that provides private and fully managed Remote Desktop Protocol (RDP) and Secure Shell (SSH) access to virtual machines.

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  1. Venkatesan S 8,315 Reputation points Microsoft External Staff Moderator
    2026-02-24T05:32:14.4066667+00:00

    Hi Vidya Jatheesh

    Thanks for reaching out in Microsoft Q&A forum,

    I get this message: An internal error has occurred within the Bastion Host, and the connection has been terminated. If the problem persists, please contact support.

    Your Azure Bastion host connection failure across all VMs, showing the "internal error" message, is a common issue often tied to network configuration, resource health, or transient service glitches.

    • Check your Bastion resource's Resource Health in the portal it must show "Available"; if degraded, await auto-recovery.
      User's image
    • In the Azure portal, go to your Bastion resource > Overview: Verify provisioning state is "Succeeded" and SKU supports your needs (Standard/Premium for native clients). Ensure AzureBastionSubnet (min /26, 5+ IPs free) exists in the VNet and hosts no other resources. Enable diagnostics to Log Analytics for BastionConnection logs if not already set.
    • Examine NSGs on AzureBastionSubnet and VM NIC/subnet:
      • Inbound: Allow TCP 443 (GatewayManager service tag) and RDP/SSH (3389/22 from VNet).
      • Outbound: Allow 443/22/3389 to VNet/internet (AzureCloud tag). Run Connection Troubleshoot in Bastion's Help tab via Network Watcher for automated diagnostics. Test incognito mode in Edge/Chrome, disabling VPNs/firewalls temporarily.

    Reference:

    Troubleshoot Azure Bastion | Microsoft Learn

    Kindly let us know if the above helps or you need further assistance on this issue.

    Please do not forget to 210246-screenshot-2021-12-10-121802.pngand “up-vote” wherever the information provided helps you, this can be beneficial to other community members.

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