I have an AM335x based IOT system where the CPU can initially boot over its USB interface using RDNIS and TCPIP/DHCP/TFTP. I need to run a DHCP server on a Fedora33 host to support the DHCP requests from this CPU. In this scenario the CPU brings its USB RDNIS interface up and down about 3 times.

In a old Fedora system (probably Fedora 23) this worked fine, however I am trying to update our boot system to run on Fedora33 and am having problems with the DHCP server. It has a basic /etc/dhcp/dhcpd.conf file that I have used before that dishes out IP addresses for the subnet 10.0.0.0 netmask 255.255.255.0 (as below). I have configured a usb0 interface with NetworkManager that uses a static IP address of 10.0.0.1.

I am having two problems:

1. If you try and start the DHCP server when the usb0 interface is down (not connected or CPU not driving a RDNIS interface) then the dhcpd server will not start with the error message "Not configured to listen on any interfaces!".

2. If the usb0 interface is up, the dhcp server runs and serves an IP address to the AM335x fine, but then the AM335x close and opens the USB0 interface and I see the error message "receive_packet failed on usb0: Network is down" and the dhcp server no longer replies to requests on the newly come up usb0 interface.

I am guessing that at some time the dhcp server was changed to listen on specific network interfaces only rather than a standard host socket listening on all networks and that it does not try to reconnect to a network interface once that has gone down.

Does anyone know of a configuration option to get the dhcp server to listen on all network interfaces in a general way or to retry its network connection when the interface goes down and up ?

Or do I have to get NetworkManager to stop/start the DHCP server for this particular usb0 network interface (yuck!) ?

Terry

============

/etc/dhcp/dhcpd.conf

subnet 10.0.0.0 netmask 255.255.255.0 {
    default-lease-time    1209600;    # Two weeks
    max-lease-time        31557600;    # One year
    range            dynamic-bootp 10.0.0.128 10.0.0.250;
    option    subnet-mask        255.255.255.0;
    option    domain-name        "usbnet";
    option    nis-domain        "usbnet";
    option    nis-servers        10.0.0.1;
    option    domain-name-servers    10.0.0.1;
    option    ntp-servers        10.0.0.1;
    next-server            10.0.0.1;
    use-host-decl-names             on;
    allow bootp;
    allow booting;

    if substring (option vendor-class-identifier, 0, 10) = "AM335x ROM" {
        filename "vlim/u-boot-spl.bin";
    }
    elsif substring (option vendor-class-identifier, 0, 10) = "DM814x ROM" {
        filename "vlim/u-boot-spl.bin";
    }
    elsif substring (option vendor-class-identifier, 0, 17) = "AM335x U-Boot SPL"     {
        filename "vlim/u-boot.img";
    }
    else {
        filename "uImage";
    }

}
_______________________________________________
users mailing list -- users@lists.fedoraproject.org
To unsubscribe send an email to users-le...@lists.fedoraproject.org
Fedora Code of Conduct: 
https://docs.fedoraproject.org/en-US/project/code-of-conduct/
List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines
List Archives: 
https://lists.fedoraproject.org/archives/list/users@lists.fedoraproject.org
Do not reply to spam on the list, report it: 
https://pagure.io/fedora-infrastructure

Reply via email to