Description:

This master document contains helpful articles on Troubleshooting on various issues.

Traces are very important in order to analyze a malfunction or a failure. Therefore the following articles have been arranged according to the necessity or possibility of trace recording.

Current Troubleshooting Guides

Titel
Troubleshooting guide: iPad / iPhone with iOS 26 cannot establish an IKEv2 connection to a LANCOM router


Troubleshooting guides with recording traces:

Articles regarding general topics

Title
Troubleshooting guide: Port forwarding not working
Troubleshooting guide: Trace cannot be started as of LCOS 10.80 RU9 due to undersized memory block
Troubleshooting guide: xDSL connection cannot be established or terminates
Error messages when dialing into a PPP remote device
Troubleshooting Guide: The Content Filter does not function correctly

Articles regarding VPN connections

Title
Creating traces on the CLI via SSH (LCOS)
Troubleshooting guide: VPN connection between two routers cannot be established or terminates
Troubleshooting guide: An additional local network cannot be accessed via VPN


Articles regarding the Advanced VPN Client

Title
Troubleshooting guide: Error message "Automatic media detection – could not find suitable media to establish a connection" in the Advanced VPN Client

Articles regarding WiFi

Title
Troubleshooting guide: A device attempting to authenticate in the Wi-Fi is rejected or the device loses the Wi-Fi connection (LCOS LX)
Troubleshooting guide: An access point cannot obtain a WLAN profile from the WLAN-Controller
Creating traces on the CLI via SSH (LCOS)
Troubleshooting guide: No access to the Public Spot login page
Troubleshooting guide: Analyzing connection problems when operating AutoWDS


Articles regarding VoIP

Title
Creating traces on the CLI via SSH (LCOS)
Explaining VoIP trace: Inbound phone call on a single account with an ISDN subscriber
Explaining VoIP trace: Outbound phone call on a single account with an ISDN subscriber
Explaining VoIP trace: Inbound phone call on a SIP trunk with an ISDN subscriber
Explaining VoIP trace: Outbound phone call on a SIP trunk with an ISDN subscriber

Articles regarding the LANCOM Management Cloud

Title
Creating an LMC trace on a GS-23xx series switch
Troubleshooting Guide: How to proceed when a device operated LCOS SX cannot be accessed in the LMC
Troubleshooting Guide: Procedure in case of inaccessibility of a unit operated with LCOS in the LMC
Troubleshooting guide: Firmware update of a LANCOM device via the LANCOM Management Cloud fails


Troubleshooting guides without recording traces:

Articles regarding general topics

Title
Troubleshooting guide: With LCOS LX devices, a configuration change cannot be carried out with LANconfig
Support configuration (*.spf file) cannot be saved via the LANtracer
Troubleshooting guide: Steps to take when the error message "resetting SERDES" is shown in the Syslog
Troubleshooting Guide: Changes in the IP router trace as of LCOS 10.20
Troubleshooting guide: As of LCOS 10.70 an access point or router with default settings cannot obtain an IP address from a DHCP server

 Articles regarding VPN

Title
Troubleshooting guide: iPad / iPhone with iOS 26 cannot establish an IKEv2 connection to a LANCOM router


 Articles regarding the Advanced VPN Client

Title
LANCOM Advanced VPN Client for Windows: How to proceed in case of problems during the software install or uninstall
Troubleshooting guide: The connection established with my LANCOM Advanced VPN Client doesn't work
Troubleshooting Guide: VPN connection with the Advanced VPN Client Version 4.10 or higher does not work with older LANCOM router models
Troubleshooting guide: Cannot establish AVC connection created with LANconfig 10.80 Rel
Troubleshooting guide: Data transmission with the Advanced VPN Client is slow

 Articles regarding WiFi

Title
Troubleshooting guide: iPhone and iPad do not login to the LANCOM RADIUS server using the MD5 signature algorithm
Troubleshooting guide: Error message 'AP configuration error 18' in LANmonitor in a WLAN controller scenario
Troubleshooting guide: LCOS LX 6.20 Rel cannot be uploaded to a LW-600
Troubleshooting guide: After DFS detection a fixed WLAN channel is not used again after the blocktime expires (LCOS LX only)
Troubleshooting guide: In a WLC scenario, changing the WPA2/3 session key types on access points with certain 802.11ac WLAN modules stops an SSID from being broadcast

 Articles regarding Wireless ePaper

Title
Troubleshooting Guide: Error message "Network-Status: Outbound-Rejected" in the ePaper status table on an ePaper access point (as of LCOS 10.40)
LANCOM Wireless ePaper: What do I do if the access point is displayed alternately as "connected" and "not connected"?
LANCOM Wireless ePaper Server: Disable regular SSH login attempts to a LANCOM ePaper access point
LANCOM Wireless ePaper: How to stop the batteries in ePaper Displays from discharging too quickly
LANCOM Wireless ePaper: What information does LANCOM Support require to process a support case?

 Articles regarding VoIP

Title
Troubleshooting: After updating to LCOS 10.42, problems with telephony occur when using a SIP PBX
Troubleshooting guide: Outgoing data connection of an ISDN subcriber (Clearmode) via a SIP line doesn't work
Troubleshooting guide: A configured SIP line cannot register with the provider


Articles regarding the LANCOM Management Cloud

Title
Troubleshooting guide: LANconfig cannot be used to pair a LANCOM R88x device with the LMC
Troubleshooting guide: Device configuration cannot be rolled out from the LMC to the LANCOM R&S®Unified Firewall
Troubleshooting guide: Device cannot connect to the LMC after being offline for a long time
Troubleshooting guide: A device configuration in the LMC cannot be rolled out to the device due to an OID error
 

 Articles regarding LANCOM R&S®Unified Firewalls

Title
Monitoring the current CPU and memory load on a LANCOM R&S®Unified Firewall via the CLI command "htop"
Troubleshooting Guide: Webpage views not possible with active antivirus on LANCOM R&S®Unified Firewalls after 01.10.2023
Troubleshooting guide: Search results from Bing cannot be called up via a LANCOM R&S®Unified Firewall with active SafeSearch
Troubleshooting guide: LANCOM R&S®Unified Firewall cannot communicate with a device over an IKEv2 connection
Troubleshooting guide: An application on a device in a LANCOM R&S®Unified Firewall network cannot communicate with the Internet

Articles regarding LANCOM Switches

Title
Troubleshooting Guide: High CPU load during SNMP monitoring on a switch with LCOS SX 4.xx due to erroneous VLAN settings
Troubleshooting guide: High CPU load on the stack master in a stack of switches with LCOS SX 5.xx
Troubleshooting guide: Switch deactivates PoE when external voltage is detected on a PoE port


 

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