haneWIN DHCP Server FAQ

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How can I set up a special profile for Android devices?

Android devices send a vendor class string "dhcpcd a.b.c.d" (a.b.c.d is a version number). A profile with vendor class string "dhcpcd" selects these clients.
In version 3.1.8 an option was added to use a client hostname as user class ID. Android clients send a hostname "android_xxx" (xxx seems to be a unique string for a device). Using the option a user class string "android" selects all Android clients.

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Windows XP SP 2 contains a firewall which blocks your haneWIN DHCP server. If we deactivate the firewall your program works fine! But we don't want to leave the computer without protection from viruses and intruders.
How can we solve this problem?

Declare the DHCP server as an exception in the Windows firewall. An example is available in file firewall.bat.

If you run the DHCP server as a service declare dhcp4nt.exe as an exception.
If you use the application declare dhcpsrv.exe as an exception.

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The server does not respond to any queries. All clients appear on the ignored list. Why?

Possible reasons are:

• You selected "Respond to registered addresses only" and did not register the hardware addresses or identifiers of the clients.
• The DHCP protocol requires a nonzero lease time. If you set the lease time to zero only BOOTP requests are answered, DHCP requests are ignored.
• A configuration profile for static/known MAC addresses/identifiers will not assign dynamic IP addresses to unknown clients.

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I've come across one problem using the haneWIN DHCP/TFTP Server. I cannot seem to boot PXE clients.

An Ethereal trace of the TFTP transfer showed:

• The PXE client sent the TFTP blksize option requesting packets of 1456 bytes.
• The MTU of the server interface was reduced to 1300 bytes and the packets were sent in two fragments.
• The PXE client ignored the fragmented packets.

Resetting the interface MTU to the default value solved the problem.

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If I create a new entry with the option 82 informations (circuit ID + remote ID) the DHCP DISCOVER request send by the switch to the DHCP server contains the option 82 (see attached Ethernet Analyser protocol) but the server does not respond. Why?

From your analyser protocol you have a "transparent relay agent".

BOOTP: Relay Agent IP Address = All 0's IP Broadcast

Relay agent information in DHCP requests without a relay agent IP address is accepted from "trusted" interfaces only. To mark a DHCP server interface as "trusted" click under "Preferences-Interfaces" on the check mark until a lock appears for the interface IP address.

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Ich erhalte unter Windows XP die Fehlermeldung "Start auf Port 67 fehlgeschlagen."
Können Sie mir sagen warum? Der DHCP-Dienst läuft nicht.

Wahrscheinlich haben Sie schon einen anderen DHCP Server gestartet.
Schauen Sie einmal mit

netstat -o -na

nach, ob es einen Prozess gibt der auf Port 67 lauscht.
Anhand der angezeigten Prozess-ID können Sie dann mit dem Task-Manager den Prozess ermitteln.