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ESP Logs

1 Introduction

This Technical Note provides supplementary information about the Edge Security Pack (ESP) logs in the Kemp LoadMaster. For further information on ESP in general, refer to the ESP Feature Description on the Kemp Documentation Page.

1.1 Related Firmware Version

Published with LMOS version LTS. This document has not required substantial changes since LTS. However, the content is in sync with the latest LoadMaster LTS firmware.

2 ESP SSO Debug Logs

ESP SSO debug logs are extensive. The primary purpose of these logs is to provide deep insight into processing and developer-level debugging information. While these logs are not documented, they are verbose in nature. They can be examined for information and parsed where necessary.

These logs are debug level and are disabled by default under normal operating conditions.

Generally, these logs are only enabled in collaboration with Kemp Customer Support personnel, to provide assistance with troubleshooting problematic flows.

3 ESP Extended Logs

These logs are generated from the L7 layer of the LoadMaster system. They provide insight into ESP and security-related events on the system. The format of these logs rarely change, unless there is a specific request to add extra information (which typically would be new data at the end of the string).

Three identifiers are used:


These map to the corresponding files on the system:

  • /var/log/userlog/connection
  • /var/log/userlog/user
  • /var/log/userlog/security

For more information on each of the log types, refer to the sections below.

3.1 Connection Logs

The connection logs provide information relating to the client, Virtual Service, Real Server, and the nature of the connection (if SSL is in use or not).



SSL accept on "VSIP:Port" from "Client IP:Port"



Connect from "ClientIP:Port" to "RSIP:Port" using "VSIP:Port"

3.2 User Logs

User logs reflect the activity of the user. The logs have the following format.



"VSIP:Port" ("RSIP:Port") User "USERNAME" requested|attempted "HTTP METHOD" "URI" "USERAGENT"


USERNAME reflects the user

The log indicates what the user requested OR attempted

HTTP METHOD reflects the HTTP method used, for example, GET or POST

URI comprises of http or https, the host being accessed, and the path and query as presented

USERAGENT is the User Agent header from the HTTP request (if enabled to be included). To enable this, go to System Configuration > Miscellaneous Options > L7 Configuration in the LoadMaster Web User Interface (WUI) and tick the Include User Agent Header in User Logs check box.


The user logs also explicitly shows log off activity.



"VSIP:Port": User "USERNAME" logged off



For common activity events (for example, log on and access denied), or if a dialogue is required between the client and LoadMaster (for example, for two-factor authentication), the user logs capture this detail in a simple user log message.



"VSIP:Port": User "USERNAME" "MESSAGE" from "HOST"

Where the MESSAGE can be:

  • logged on
  • denied access
  • blocked access
  • requires passphrase
  • requires re-enter passphrase
  • requires pin
  • requires re-enter pin
  • requires password reset


In LoadMaster firmware version 7.2.51, ESP user logs were expanded to be more useful and applicable to enterprise customers with extensive logging infrastructure. User Authentication, Authorization, and Accounting (AAA) information is included in the logs, including the time of request, username, domain, AAA server, AAA protocol type, AAA result, and error message. For further details, refer to the following article: Expanded ESP User Logs.


In LoadMaster firmware version 7.2.53, the ESP client session logging was further enhanced. The LoadMaster logs:

  • The initially created ESP session 

  • If an ESP session is deleted

For further details, refer to the following article: Enhanced ESP Client Session Logging.

4 Security Logs

These logs are generated when configuration on the LoadMaster prevents access to a service, or the LoadMaster detects something malicious regarding the request.



Attempted XSS attack on "VSIP:Port" from "ClientIP:Port" (dtcode "INTERNAL DETECTION CODE")



Blocked access to invalid "TARGET" "HOST" from "ClientIP:Port" to "VSIP:Port"\n


  • TARGET is the directory or host
  • HOST is the host information from HTTP request or [No host specified]



Blocked SMTP access to "MAIL ADDRESS" from "ClientIP:Port" to "VSIP:Port"

SMTP parse failure of data from "ClientIP:Port" to "VSIP:Port"

Last Updated Date

This document was last updated on 19 March 2021.