Network, routers, DHCP and PXE

[Svein Halvor Halvorsen]

Manolis Kiagias wrote:
>> Now, on this network, most of the computers get their IP by means of
>> DHCP. Except our home audio server, which have a hard coded ip
>> address in rc.conf, set to something within the range of the dhcp
>> server (10.0.0.2-10.0.0.253). The server seems to pick this up, and
>> don't give that address away to someone else.
> 
> You may also want to ensure that the router will never allocate your 
> static IP address to someone else.
> Look at the DHCP router settings either for DHCP scope (set it to 
> narrower values, and use a static IP outside the range) or for something 
> like exceptions / exclusion where you can mark a specific IP that DHCP 
> will never assign.

Yeah, but even though the router has customizable values for this
range, and issues a warning when i try to change them, it still
doesn't change them when I click "yes" on the warning. It is
pre-configured to 10.0.0.2-10.0.0.253

I could of course use 10.0.0.254 for my static ip, but my room mate
also wants a static address.

>> I've tried using other addresses outside this range, like 10.0.1.1,
>> but that doesn't work. All network access is lost when I do that.
> 
>  10.0.1.1 is a different network (I assume your netmask is 
> 255.255.255.0, but check your router or your clients)

You're right! But how do I make the entire 10/24 adress space
available? It would be "clean" (I guess) to have a different adresse
scheme for the static adresses.

Anyway, it this point this isn't really critical, as the router
figures out that the addresses I use, are in fact in use, and keeps
them out of its dhcp address pool.


> You will have to shutdown the router's DHCP. Probably disable it 
> permanently and assign this function to a machine.
> The DHCP of the router also sends you the following information (besides 
> IP address):
> 
> - DNS Server(s): Either the ones used by your ISP (consult its website) 
> or its own address (i.e. 10.0.0.1). Most routers send their own address 
> as a DNS server and perform the resolution by sending your request to 
> ISP servers.
> - Gateway address: This is always the router's local IP address (i.e. 
> 10.0.0.1)
> 
> If you setup your own DHCP server, make sure it is set to send this info 
> as well. (These are commonly known as DHCP options)

So as long as I make my own DHCP server act the same way as the
router one, I should be fine? NAT and all will work?

Is there a way to debug the DHCP response from the current router
dhcp server? So I can see what options it actually sends? dhclient
doesn't seem to have a "more verbose" option, only less.


	sv.