DHCP offer ignored for some clients.

[zglurb]

Issue Details

• Version of AdGuard Home server:
  • v0.107.3
• How did you install AdGuard Home:
  • Docker
• How did you setup DNS configuration:
  • Synology NAS
• If it's a router or IoT, please write device model:
  • DS1513+
• CPU architecture:
  • x64
• Operating system and version:
  • DSM 7.0 (Linux)

Expected Behavior

I've just installed AdGuard Home and enabled the DHCP server after disabling the one from my router.
I expect my devices to get their network configuration from the AdGuard's DHCP server.

Actual Behavior

It's working fine for all of my devices except for one that ignores DHCP offers.
In an old issue, I've read this :

If Unix-like (i.e. Linux, MacOS, FreeBSD, etc.), what DHCP client is used and how is it configured? The thing is that some clients may be configured to ignore some specific DHCP OFFERs. For example, dhclient on FreeBSD has an option -u which forces dhclient to reject leases with unknown options in them. The default behaviour is to accept such lease offers.

I don't really have access to my device. It's an IoT device, not a computer or a phone so i can't check that. But i figured it might be the issue.

Using Wireshark I compared the DHCP offers from my router (which is accepted) and from AdGuard (which is ignored) and the only difference I could spot was this option in AdGuard's offer that was not in my routers.

Option: (61) Client identifier
    Length: 7
    Hardware type: Ethernet (0x01)
    Client MAC address: <mydevicemacaddress> (<mydevicemacaddress>)

Is there an option to prevent AdGuard Home sending this so I can test if this is really the cause of the issue?

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[Birbber]

@zglurb Apologies for the long silence!
Is this issue still reproducible on the latest release?

[zglurb]

Yes, I still have this issue with v0.107.9.

[EugeneOne1]

@zglurb, hello again. This is actually an insteresting case. Could you please provide some details about the aforementioned device? Is it somehow old? FYI, the RFC 6842 states that the option must be present if client sends it.

We've actually implemented the del option in the latest edge build. You may find the usage hints on it in the wiki. Could you please perform the desired test?