This document guides you through the process of troubleshooting an SSH connection to an ESX host.

Note: This article applies only to ESX 4.x and earlier versions. In ESXi 4.1 and later, VMware recommends that you use Tech Support Mode. For more information, see Using Tech Support Mode in ESXi 4.1 and ESXi 5.0 (1017910).

Symptoms:

• You are unable to connect to an ESX host using SSH.
• You receive one or more of these errors when trying to connect:
  
  
  • Network error: Connection refused.
  • Error code: 24577 (0x6001)
  • Error code: 110 (0x006E)

VMware VirtualCenter 2.0.x
VMware ESX 4.0.x
VMware ESX Server 3.5.x
VMware vCenter Server 4.1.x
VMware ESX 4.1.x
VMware ESX Server 3.0.x
VMware vCenter Server 4.0.x
VMware VirtualCenter 2.5.x

Validate that each troubleshooting step below is true for your environment. Each step provides instructions or a link to a document, in order to eliminate possible causes and take corrective action as necessary. The steps are ordered in the most appropriate sequence to isolate the issue and identify the proper resolution. Do not skip a step.

1. Verify that there is network connectivity between the SSH client and the ESX host. For more information, see Testing network connectivity with the Ping command (1003486) .
   
   
2. Verify that port 22 on the ESX host can be reached from the SSH client machine. For more information, see Testing port connectivity with the Telnet command (1003487).
   
   
3. Verify that the username and password is correct by logging directly in to the console. A common error is to use an incorrect username or password, which causes a login failure and an access denied error message to appear.
   
   
4. Verify that the SSH Daemon is running. For more information, see Verifying that the Secure Shell Daemon is running on an ESX host (1003906).
   
   
5. Verify that user is permitted to access the host via SSH. For more information, see Enabling root SSH login on an ESX host (8375637).
   
   
6. Verify that the ESX host firewall permits SSH connections. For more information, see Configuring the ESX host firewall for SSH (1003808).

Note: If your problem still exists after trying the steps in this article:

• Gather the VMware Support Script Data. For more information, see Collecting Diagnostic Information in a VMware Virtual Infrastructure Environment (1003689).
• File a support request with VMware Support and note this Knowledge Base article ID (1003807) in the problem description. For more information, see How to Submit a Support Request.

Note: To enable SSH access for local user accounts created on ESX 4.1, see Local users created on ESX and ESXi 4.1 systems cannot log in (1024235).

Testing network connectivity with the ping command
Testing port connectivity with Telnet
Collecting diagnostic information in a VMware Virtual Infrastructure Environment
Configuring the ESX host firewall for SSH
Verifying that the Secure Shell Daemon is running on an ESX host
Using Tech Support Mode in ESXi 4.1, ESXi 5.x, and ESXi 6.x
Local or Active Directory Domain users on ESX and ESXi 4.1 systems cannot log in
Não é possível conectar a um host ESX usando o Secure Shell (SSH)
无法使用 Secure Shell (SSH) 连接到 ESX 主机
无法使用 Secure Shell (SSH) 连接到 ESX 主机
No es posible conectarse a un host ESX mediante Secure Shell (SSH)
セキュア シェル (SSH) を使用して ESX ホストへ接続できない
HBA の proc 情報を使用して、ファイバチャネルの接続に関する問題判別をする方法
多数のデータストアがある環境でステートレス キャッシュが有効化されていると、ホスト プロファイルのコンプライアンス チェックがタイムアウトする
Enabling root SSH login on an ESX host