Hi all, I hope I am at the right place for some questions related to Modemmanager and how host interfaces actually get their IP configuration assigned. Apologies if I'm at the wrong place.
Assuming a mobile connection via any of the available control protocols (QMI/AT/etc) has been initiated. The mobile modem firmware has established a bearer connection and via the (3GPP PCO -Protocol Control Options amongst others) an IPv4 address has been received from the mobile network. Now for the actual data interface on the host a DHCPv4 client could be run to retrieve the IP address from the modem (this assumes the Modem runs a DHCP server). But likewise via control protocol (QMI/AT/etc) one could retrieve the IP address from the modem and configure the data interface with the retrieved result. This question actually does extend to IPv6, here also via the available control protocol (QMI/AT/etc) the connection is initiated. It is the modem firmware that runs a SLAAC client process to receive a /64 prefix. Then the data interface on the host is able retrieve that prefix (via a SLAAC/DHCPv6 client procedure (depending on the modem firmware capabilities) from the modem. Also here the alternative option exists to retrieve the IPv6 prefix (+ other items like Ipv6DNS, MTU size, or even PD - (e.g quectel AT+QIP6CFG="PD_addr") via the control interface from the modem and apply the result to the data interface. What is the modem manager approach in this ? It looks like always the data interface needs to use DHCP/SLAAC kind of client processes. As I prefer to be independent of specific modem firmware (DHCP) server processes (which are often outdated/have limited DHCP options supported) I am interested to understand the pros/cons of the above approach (and the modem manager support of this approach). Thanks ! /Arjen
