It took at least 1 minute to broadcast mavlink message on UDP

PX4 Autopilot Flight Controllers 💻
1

Hi
I am using a single Ethernet cable to directly connect the computer and the flight controller.
I noticed that it will took at least 80s for the computer receive mavlink broadcast message.
the computer IPv4 is 192.168.0.10 Gateway is 192.168.0.254,
the Flight controller IPv4 is 192.168.0.3 Gateway is 192.168.0.245
software version : v1.14.3
hardware version : Holybro v6x pro

nsh> netman show
DEVICE=eth0
BOOTPROTO=fallback
NETMASK=255.255.255.0
IPADDR=192.168.0.3
ROUTER=192.168.0.254
DNS=192.168.0.254

when it haven’t ready , run command on the nsh: ifconfig

eth0    Link encap:Ethernet HWaddr 7a:64:e7:a9:46:ad at UP
         inet addr:0.0.0.0 DRaddr:192.168.0.254 Mask:255.255.255.0

when it ready, run command on the nsh: ifconfig

nsh> ifconfig   
eth0    Link encap:Ethernet HWaddr 7a:64:e7:a9:46:ad at UP
        inet addr:192.168.0.3 DRaddr:192.168.0.254 Mask:255.255.255.0

I don’t understand why it took so long for the ethernet to get ready.

2

I solved the problem by set the BOOTPROTO=static
In the fallback mode, firstly it will wait for the dhcp sever to give ip address, then after 80s, it find it can’t get ip address from dhcp sever. then it will use the written ip address in the file.
The static option doesn’t have the problem. It will get the ip address firstly.