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ECS Connection Manager Release Notes

ECS Connection Manager Version is a feature and bug fix update for the General Availability (GA) branch, made available on 30 June 2022. Please read the sections below before installing or upgrading to this release. 


Before You Upgrade (READ ME FIRST)
  Generation of 4096-bit DHE Key
  Best Practices Cipher Set
  Supported Models for Upgrade
  Upgrade Path
  Upgrade Patch XML File Verification Notes
  Code Signing Certificate Update
New Features
  GEO: BIND Upgrade and EDNS Client Subnet (ECS) Support
  GEO: Manage FQDN UI Sorting and Filtering
  GEO: Increase Limit on IPs per FQDN to 256
  WAF: UI Updates
Change Notices
  Kubernetes Ingress Controller (KIC): Support for Kubernetes 1.22
  WAF: Increased Request Body Size Limit
  WAF: Order of Rule Processing
Security Updates
  WAF: Engine Update for CVE-2021-42717
Issues Resolved
New Known Issues
Existing Known Issues

Before You Upgrade (READ ME FIRST)

Please pay special attention to the issues below before you begin an upgrade to this LMOS release.

Generation of 4096-bit DHE Key

During an upgrade to this version of ECS Connection Manager from a version prior to, a new 4096-bit DHE key is generated. On smaller deployments, this can lead to significant CPU and memory consumption that could impact regular virtual service traffic. So, Kemp strongly recommends that this update be performed in a maintenance interval. 

Best Practices Cipher Set

In LMOS, the BestPractices cipher set was updated. If you are upgrading from a version prior to, this change is effective immediately after upgrade to this release. This change was made to improve security and conform to the latest industry best practices.

If you depend on any of the cipher sets being removed from the BestPractices set, then before you upgrade you must create a custom cipher set that contains these ciphers and assign this new custom cipher set to the Virtual Services that are currently using the BestPractices cipher set. After this is done, you can upgrade to this release and your services will continue to use the old ciphers. If you do not, then after upgrade any clients that depend on these ciphers being available will no longer be able to connect.

It is recommended, however, that you migrate your services as soon as possible to use the new BestPractices cipher set. For more information on the cipher suites removed from the set, please see the LMOS Release Notes.

Supported Models for Upgrade

This release of LMOS is supported on the Hardware and Virtual models shown in the first three columns of the table below. It is not supported and should not be installed on any model listed in the two columns at right. This update patch can be applied to any supported model regardless of licensing (e.g., SPLA, MELA) or platform (e.g., hardware, local cloud, public cloud).



Supported Bare Metal Models









LM-UCS Series



If your model number is not listed above, please see the list of End of Life models.

Upgrade Path

You can upgrade to this release of LMOS from any previous 7.2.x release. For full upgrade path information, please see the article Firmware Upgrade Path.

Code Signing Certificate Update

On 27 May 2022, the certificate used to sign release artifacts for version 7.2.56.x and prior releases expired. For most customers, this will not impact normal operations, as explained in this Announcement on the Support website.

All releases that occur after the above date (e.g., LMOS will be digitally signed using a newly obtained code signing certificate. 

New Features

GEO: BIND Upgrade and EDNS Client Subnet (ECS) Support

BIND is an open source software suite provided by the Internet Systems Consortium (ISC) for interacting with the Domain Name System (DNS). The BIND version has been updated to version 9.16.24. BIND 9.16 is the current “Stable/ESV version”, according to the ISC website.

Alongside this update, GEO has been enhanced with Extended DNS (EDNS) Client Subnet, or ECS, support. This is a new global option on the GSLB Miscellaneous Params page, which is disabled by default on upgrade and enabled by default on a fresh install. With this feature enabled, GEO will be able to provide better greographic location determination over previous releases.

The ECS feature leverages the larger EDNS packet size and the Client Subnet field that can be set by the client making the DNS request. When a DNS query arrives with an ECS value set, that value will be used as the client location for all DNS operations, with the exception of deny lists. If there is no ECS information in the query (i.e., it was either never supplied by the client or was stripped out by an intervening DNS server that doesn’t support EDNS), GEO will behave as in previous releases.

GEO: Manage FQDN UI Sorting and Filtering

The GEO Manage FQDN UI has been enhanced to provide:

  • Sorting: Controls on the table columns allow for sorting FQDNs by Name, IP Address, or Availability.
  • Filtering: You can limit the number of FQDNs displayed by selecting one of the Name or IP address radio buttons at the top right of the table; typing in the text box immediately limits the display to matching FQDNs. These can then be sorted using the controls above. Clearing the text box cancels filtering and displays all items.

GEO: Increase Limit on IPs per FQDN to 256

The number of IP addresses permitted in a single FQDN (Fully Qualified Domain Name) has been increased from 64 to 256. This allows traffic to a single FQDN to be directed to up to 256 endpoints, providing the ability to scale across large load spikes and keep services highly availability.

WAF: UI Updates

The Web Application Firewall > Access Settings page of the UI now displays the version of the currently installed OWASP Core Rule Set (CRS).

The WAF section of the Virtual Services Properties page has been updated to no longer allow individual custom rules to be selected. Custom rule selection is supported on a file basis only.

Change Notices

Kubernetes Ingress Controller (KIC): Support for Kubernetes 1.22

The KIC addon software has been enhaced to support the new Ingress API path element syntax ( now required by Kubernetes v1.22. The old endpoint (v1beta) has been deprecated and is no longer supported with v1.22.

WAF: Increased Request Body Size Limit

In previous releases, the maximum configurable Request Body Size Limit for a POST body was 10 MB, with a default of 1 MB. When this WAF option is enabled, any requests that are larger than this limit are blocked by the WAF engine. The configurable limit has now been increased to 25 MB. This setting is available in a WAF-enabled Virtual Service under WAF Advanced Options, when the Inspect HTTP POST Request Bodies setting is enabled. Note that increasing the limit above the default of 1 MB will place additional demands on system memory, depending on the number of Virtual Services on which this option is enabled and the level of traffic passing through the Virtual Services.

WAF: Order of Rule Processing

To conform to recommended best practices for using the OWASP Core Rule Set, the order of WAF rule processing has been changed so that custom rule files added by the user are now processed before the OWASP CRS rules. In previous releases, the OWASP rules were processed first.

Security Updates

WAF: Engine Update for CVE-2021-42717

The WAF engine has been updated to ModSecurity 2.9.5 to close the CVE-2021-42717 vulnerability. As a result, a new JSON Depth Limit parameter has been added to the WAF Advanced Options that controls the depth to which JSON data is examined by the WAF engine. The default of 10000 is the recommended value. Lower values may cause a match failure if not enough data is examined to produce a match; higher values may cause the WAF engine to run slower as the amount of data examined increases.

Issues Resolved


SNMPv2c Walk: Fixed an issue that caused the SNMP Version 2c Walk command to return no data.


AWS VLM UI: Fixed an issue that caused the message “Unable to resolve host” to appeara on the Debug Options page.


Statistics: Fixed an issue that caused the statd daemon to repeatedly restart when a VXLAN interface is defined with the largest possible VXLAN ID. 


WAF and Remote Logging: When both WAF and Remote Logging are enabled, WAF processing and Layer 7 processing can hang, leading to a service outage. WAF has been modified to continue processing even when log entries are not being processed and a watchdog process will now monitor the logging pipeline to recover remote logging processing if it stops.


Network Telemetry: Fixed an issue with the version of the Network Telemetry Add-on where flow data is not sent to the Flowmon Collector and the following message appears repeatedly in the system log:

flowd: Monitor for interface 0 (pid xxxxx) died - exited with status 1


LDAP / LDAPS Health Checks: Fixed issues that occurred in where LDAP health checks start failing immediately after upgrade, possibly also causing unrelated HTTPS health checks to fail.


Kubernetes Ingress Controller (KIC): Fixed an issue where ingress annotations were not working properly because of un-escaped spaces in lists.


Server Side KCD Authentication: Fixed issues that resulted in users being able to log in despite the failure of KCD due to a misconfiguration (e.g., configured with an invalid domain).


SAML Authentication: Fixed an issue that caused SSO sessions to be killed by every few hours.


GEO: Fixed issues that could cause the configuration file generation number and the SOA serial number to become out of sync over time.


UI Certificate Login: Fixed an issue observed in where enabling UI Remote Access with client certificates using the API (not the UI) resulted in login failures.


Single Sign On (SSO): Fixed an issue in previous releases where long login delays and authentication failures were observed, typically on units with lower CPU and memory.


Virtual Service Certificate UI: Fixed an issue in the UI where, when reencryption is disabled, changes to intermediate certificate assignment are not applied.


New Known Issues


GEO Performance: Starting with LMOS, a performance degradation has been seen where Queries per Second (QPS) can be up to 50% lower than with version 7.2.54 and previous releases. This issue will be addressed in the LMOS release.


GEO EDNS Client Subnet (ECS): It has been observed that with ECS enabled and an FQDN with the default private/public behavior selected, a private-network client may receive a non-routable DNS response in certain scenarios.


Existing Known Issues


GEO Cluster Status: When adding a Cluster that is unavailable (DOWN) to a Site, the Site may reflect the Cluster's status as available (UP) for a short time before changing to DOWN.  



GEO: Modifying an FQDN entry displays a spurious error on the system console, similar to the one shown below. The FQDN is modified properly.

<FQDN>:794 Uncaught ReferenceError: disp_addrr_elements is not defined

    at <FQDN>:794

(anonymous) @ <FQDN>:794



GEO: Cannot configure GEO into partnering mode unless there is at least one FQDN already defined.



Certificate-Based Administrative Login: Using a certificate that does not have a SAN attribute (i.e., no Principal Name) results in a failed login attempt.



GEO: No statistics (queries per second, etc.) are displayed for a site if the FQDN is configured to use the "All Available" Selection Criteria.



Client Certificates: Authentication may be denied if multiple "Other names" are present in the client certificate.


LDAP UI Access: Under certain circumstances, a user that has no LDAP credentials can gain access to the UI.


LDAP/Syslog: StartTLS is not working when the Server Certificate Validation flag is enabled.


GEO: If you add a Zone Name to GEO after you have created working FQDNs, GEO may no longer respond to queries for one or more of the FQDNs after the Zone Name is added. The workaround is to remove and then re-add the FQDNs that are no longer working.


VS Redirects: If you attempt to upload a new redirect error HTML file to a Virtual Service with Not Available Redirection Handling enabled while traffic is currently being redirected, then traffic to the VS is dropped. Click the Error Message radio button in the UI and the VS begins accepting connections again.


SSO Timeout: In LMOS, a fix was introduced for issues that caused an SSO client to not be properly logged out when the configured session timeout expires. It has been observed that while sessions do timeout, they are not always closed immediately upon the expiry of the timer; it can take close to a minute longer for the session to be closed.



ESP Verify Bearer Header: An error is not returned when an encrypted token is received and there is no SSL certificate assigned to the VS to decrypt the token.



ESP Verify Bearer Header: Validation is not working when "Allowed Virtual Hosts" and "Allowed Virtual Directories" are blank on the Virtual Service.


Single Sign On: When Form Based Authentication is enabled on the server side, it is possible that after filling out correct credentials and submitting the login form, the form will be presented again; once the second login form is submitted with correct credentials, the login succeeds.


ACLs and Real Servers: Real Servers located on networks on which ECS CM also has an IP address are always allowed to access Virtual Services on that network interface regardless of any access control list (ACL) settings on ECM CM. For Layer 7 services, this issue can be worked around using Content Rules. The workaround for other services is to block access for local Real Servers (if desired) on another network device (firewall, switch, router, etc.).


ESP / SSO: The ESP Permitted Group SID(s) setting is not working as expected when configured on a SubVS.


WAF / Compression: With Web Application Firewall (WAF) enabled, compressed files are incorrectly decompressed. As a workaround, ensure compression is enabled in VS Advanced Properties by selecting the Enable Compression option.


Downgrade: If an Azure VLM is downgraded to the LTS firmware release (7.1.35.x), the WUI may display in the top right-hand corner that the VLM is a Hyper-V VLM. This indicates that the Azure VLM Add-On Package must be added to the system to provide full Azure VLM functionality. If this occurs, please contact Kemp Support to get the required add-on package.


Hardware Support: The hardware models LM-X15, LM-X25, and LM-X40 do not support the following SFP+ modules: LM-SFP-SX (SFP+ SX Transceiver 1000BASE-SX 850nm, 550m over MMF), LM-SFP-LX (SFP+ LX Transceiver 1000BASE-LX 1310nm, 10KM over SMF).


HA / NTP: Configuring NTP for the first time after the system is running in High Availability (HA) mode and when the current time on the machines is not correct, may cause the systems to both go into the Master state.


ESP / RADIUS: In a configuration with ESP and Radius server-side authentication enabled, sessions may fail to be established.


RADIUS / IPv6: IPv6 is not supported by the current RADIUS implementation for both WUI Authorization and ESP Authentication.


Networking: Azure devices are not translating the additional network address between the Master and Slave correctly.


SharePoint Virtual Services: A second authentication prompt is presented when a file is uploaded to SharePoint with the following configuration: WAF is configured with Process Responses enabled on the main Virtual Service and KCD is enabled on the SubVS level for server-side authentication.


HA: An issue exists when setting up 2-armed HA Virtual in Azure.


HA: Configuring HA using eth1 on Amazon Web Services (AWS) does not work.


WAF: The vsremovewafrule RESTful API command does not allow multiple rules to be removed. This problem has been fixed.


Exchange 2010 Virtual Services: A WAF, ESP, and KCD configuration with Microsoft Exchange 2010 is not supported.


Browser Support: (Safari) When adding a Real Server to a Virtual Service or SubVS using the Safari browser, the list of available Real Servers is not available.


Statistics: When upgrading firmware from version 7.1.35.n, CPU and network usage graphs are not appearing. As a workaround, reset the statistics in the WUI.


Clustering: In a cluster configuration, a new node can be added with the same IP address as an existing node.


WAF: There is an API command to list individual rules in a ruleset, but there is no command to list the available rulesets themselves.


GEO: DNS TCP requests from unknown sources are not supported.


Networking: Unable to add an SDN controller using the RESTful API/WUI in a specific scenario.


SharePoint Virtual Services: Microsoft Office files in SharePoint do not work in Firefox and Chrome when using SAML authentication.




























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