With Wireshark on the client device, I tested multiple times and measured a delay of up to 140 seconds.
Using the firewall log, I noticed that the DHCP packets are *accepted* into the input chain (in other words, these are NOT dropped), therefore it isn't a firewall issue.
So I did an experiment:
- I shutdown the Mikrotik device via Webfig.
- Disconnected the Mikrotik device power cable.
- Waited about 10 seconds.
- Started Wireshark on the client device.
- Re-connected the Mikrotik device power cable.
- Waited until client received IP address.
- Inspected Wireshark and the Mikrotik Logs.
I got these findings:
- From the client prespective, it took 79 seconds between the first DHCP packet that the client sent to the router ( = Mikrotik device) until the first DHCP Offer by the DHCP Server.
- From the Mikrotik device perspective, from the Logs webpage: it took 55 seconds between the "link up" message (for the corresponding Ethernet port) until the DHCP IP Address assignment message (by the DHCP Server). The *same* time (55 seconds) it took for the DHCP firewall accept rule to log the DHCP Discovery packet that the client sent.
Is it normal that it takes this amount of time?
How much time is considered NOT normal?
Note that the client is sequentially sending *multiple* DHCP Discovery/Request packets (with a 2 seconds to 25 seconds delay between each packet) until the DHCP Offer is detected.
