Modifying IP configuration hosts

[Aleksander Morgado]

Hey Carlos,

>
> I have been testing a Quectel RG50xQ module with ModemManager 1.16.6 and everything works great, but I have noticed that my device gets an IP configuration with a subnet that can be /28, /29, /30 depending on the IP, and sets a default gateway. This tests are within a private APN with fixed IP addresses per SIM. For example:
>
> mmcli -b 0
>   ------------------------------------
>   General      |           path: /org/freedesktop/ModemManager1/Bearer/0
>                      |           type: default
>   ------------------------------------
>   Status         |      connected: yes
>                      |      suspended: no
>                      |      interface: wwan0
>                      |     ip timeout: 20
>   ------------------------------------
>   Properties   |       apn: sa.pn5g.p2p
>                      |        roaming: allowed
>                      |        ip type: ipv4
>   ------------------------------------
>   IPv4 configuration
>                      |        method: static
>                      |        address: 10.111.1.5
>                      |        prefix: 30
>                      |        gateway: 10.111.1.6
>                      |        dns: 85.62.229.135
>                      |        mtu: 1500
>
> I am pretty sure that this behaviour is not specific to ModemManager, but is there a way to change this configuration? In this network we have peer to peer enabled but because of this network settings we cannot communicate 10.111.1.5 with 10.111.1.4 for example.
>

This is not something that we can change in ModemManager; we just
expose what the modem tells us to use, which in turn is received from
the network.
But you're free to add additional routing rules for a wider netmask
really in the host itself. I'd guess the problem here is the
forwarding in the gateway, not so much in the settings of the
different network elements.

-- 
Aleksander
https://aleksander.es