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Amiga computer related discussion => Amiga Software Issues and Discussion => Topic started by: freqmax on June 10, 2013, 07:54:21 PM
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I find the current DHCP implementation configuration files a pain to deal with. The protocol also seem a bit more complex than the requirement. Sometimes I had the thought that writing a new DHCP server is easier than to write the configuration file..
The only catch being that current PXE stuff assumes DHCP. But anyway for some cases it might just be useful to write a small network service that upon request "MAC 11:22:33:44:55:66 wants config" responds with "IP 1.2.3.4 mask 0xff000000". Plain and simple.
Any thoughts?
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I find the current DHCP implementation configuration files a pain to deal with. The protocol also seem a bit more complex than the requirement. Sometimes I had the thought that writing a new DHCP server is easier than to write the configuration file..
The only catch being that current PXE stuff assumes DHCP. But anyway for some cases it might just be useful to write a small network service that upon request "MAC 11:22:33:44:55:66 wants config" responds with "IP 1.2.3.4 mask 0xff000000". Plain and simple.
Any thoughts?
Yes DHCP sucks, you could use a UDP broadcast of your own. However part of the fun would be making it use DHCP.
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DHCP has some short-comings, but it's still useful. In particular, most DHCP server implementations blindly accept IP address requests provided they don't collide with another existing lease or reservation, or active IP if it's set to ping an IP. This can cause devices which roam between networks with the same IP scheme to have incorrect settings. Though Network Location Awareness does a fairly good job to overcome this.
For instance, a home network has IP scheme 192.168.1.0/24 with a DNS server of 192.168.1.1, the laptop has been assigned IP 192.168.1.64. The laptop gets taken to an office network which also has an IP scheme of 192.168.1.0/24 but the gateway at 1.1 does not offer DNS services and instead gives out 8.8.8.8 as DNS.
However, when the laptop requests the IP address of 192.168.1.64, the office DHCP server sees this address is available and simply acknowledges and the laptop does not get updated configuration information, thus it still queries 192.168.1.1 for DNS which never answers.
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Ie the DHCP client must do "If this network is different then request new DHCP configuration" ..?
Ie ask for network identification, compare, if different - then reset config and request new from DHCP server.
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Pretty much. I think NLA probably checks the MAC and IP of the DHCP server serving answers and compares to the last one it talked to. The problem I described often led to users who couldn't access the Internet either because the DNS server wasn't correct or the stupid DHCP server (it happens in Windows 2003 and Solaris 8, for certain) wouldn't bother to check that the IP being requested was outside the address pool.