1.2) If the DNS cannot resolve cloud.lancom.de, you have to check whether the correct DNS server is being used:
1.2.1 Check under IPv4 → DNS → Forwarding to see whether a non-existent or malfunctioning DNS server has been specified.
DNS forwarding takes precedence over all other DNS servers stored in the device and should be checked first.
1.2.2 In the case of a plain Ethernet connection with static IP parameters, check whether the correct DNS server has been entered under Communication → Protocols → IP parameters → <name of the Internet connection>.
1.2.3 In the case of a plain Ethernet connection with dynamic IP address assignment via DHCP from an upstream router, use LANmonitor to check whether the correct DNS server has been assigned. If the DNS server is not correct, contact the administrator of the upstream router or adjust the configuration yourself if you have access to it.
Alternatively, you can read out the IP parameters received from the DHCP server by means of the CLI command ls Status/DHCP-Client/WAN-IP-List/.
1.2.4 Occasionally it can happen that the DNS servers assigned by the provider (statically or dynamically assigned) cannot be reached. In this case, enter a DNS forwarding under IPv4 → DNS → Forwarding to a DNS server of your choice.
- Enter the wildcard * for the Domain. This represents any number of characters. This enables the forwarding of all DNS queries.
- Set the Remote site to an IP address of a DNS server (in this example the Google DNS server).
2) Changing the MTU on the Internet gateway (LANCOM router):