dhcpcd-discuss

Hi List,

there is a --dhcp option to dhcpcd which seems to be needed when using 
raw-ip with qmi modems. I have systems who are being moved from 802-3 to 
raw-ip, since newer modems seem to lack support for 802-3. To keep the 
setup as generic as possible, we still would like to use dhcpcd without 
having to define too many details about the actual type of modem on 
beforehand. Hence, for gms modems using qmi and raw-ip, ideally we would 
like to just run dhcpcd in the background and it should "just work" when 
the modem connects, much as when using 802-3 (except for a -HUP to dhcpcd).

The *only* way I am able to get dhcpcd to work is by running "dhcpcd 
--dhcp -z wwp*". That always works.

However, it never works if dhcpcd is already running in the background, 
no matter if it was started with --dhcp or not, and no matter if the 
config file's allowinterfaces includes ww*.

So my questions are:

- What does --dhcp actually do in this case? man dhcpcd (at least on my 
system) does not document the --dhcp option.

- What am I doing wrong...? Kindof out of clues now. :)

ip a on wwan, before after the ip address is set:

5: wwp0s20u5u1i8: <POINTOPOINT,MULTICAST,NOARP,UP,LOWER_UP> mtu 1500 
qdisc pfifo_fast state UNKNOWN group default qlen 1000
    link/none
    inet 10.214.215.169/30 brd 10.214.215.171 scope global dynamic 
noprefixroute wwp0s20u5u1i8
       valid_lft 6868sec preferred_lft 5968sec

These are minimalistic systems using OpenRC and no NetworkManager nor 
ModemManager. Kernel is 4.9. dhcpcd is 8.1.7 from Gentoo. udhcpc works 
on the same system.

I presume this is too little info to be able to pinpoint the issue, but 
any hints are appreciated. Thanks!

BR, Tor Rune Skoglund