Explanation
The reason why the Linux server is not communicating on a network is that it is configured to use DHCP on a network that does not have a DHCP server. DHCP (Dynamic Host Configuration Protocol) is a protocol that allows a client device to obtain an IP address and other network configuration parameters from a DHCP server automatically. However, if there is no DHCP server on the network, the client device will not be able to obtain a valid IP address and will assign itself a link-local address instead. A link-local address is an IP address that is only valid within a local network segment and cannot be used for communication outside of it. A link-local address has a prefix of 169.254/16 in IPv4 or fe80::/10 in IPv6. In this case, the Linux server has assigned itself a link-local address of 127.0.0.1, which is also known as the loopback address. The loopback address is used for testing and troubleshooting purposes and refers to the device itself. It cannot be used for communication with other devices on the network.