dhcp subnet, different network relay.

[Glenn Satchell]

No. shared-network says that 58.0.0.0/8 and 14.137.118.0/24 co-exist on
the same physical wire, so it is ok to respond to requests from either
subnet with the defined range.

If you don't see any responses from the clients then you could look at the
"always-broadcast" setting in the dhcpd.conf man page - setting it true
will cause all communication between server and client to broadcast, so
the relay will forward it.

If there is some magical NAT going on somewhere then this will upset
things. Basically dhcpd expects the subnets to be defined the way that
they exist in reality. So if there is no route from the clients
14.137.118.0/24 network back to the dhcp server then something is not
right.

There is no such thing as a global subnet definition.

regards,
-glenn

On Tue, April 9, 2013 3:27 pm, Simon Collyer wrote:
> I think the problem with this is that the relay IP (58.*.*.*) is only
> relaying the dhcp request.  I won't see any request coming from
> 14.137.118.* in the actual dhcp ack.  I assume i can't put a global
> subnet in, just to accept any request from anywhere and give an ip
> from a range that is in the 14 range?
>
> //Simon
>
>
>
> Quoting Glenn Satchell <glenn.satchell at uniq.com.au>:
>
>> Looks like you need a shared-network around the 58 and 14 subnet
>> definitions. eg:
>>
>> shared-network {
>>   subnet 58.***.***.0 netmask 255.0.0.0 {
>>   }
>>
>>   subnet 14.137.118.0 netmask 255.255.255.0 {
>>          ## dhcp start  and end IP range ##
>>          range 14.137.118.2 14.137.118.253;
>>          option subnet-mask 255.255.255.0;        ## subnet
>>          option broadcast-address 14.137.118.255; ## broadcast
>>          option routers 14.137.118.254;           ## router IP
>>   }
>> }
>>
>> The values in the subnet line *must* match the ranges you offer within
>> that subnet.
>>
>> Have a look in the dhcpd.conf man page for more details.
>>
>> regards,
>> -glenn
>>
>> On Tue, April 9, 2013 11:09 am, Simon Collyer wrote:
>>> Hi all,
>>>
>>> Having a few issues with getting the dhcp server to act as a "proper"
>>> relay.
>>>
>>> Current setup or process is as follows:
>>>
>>>
>>> (home user) -> (wholesale) -> **DHCP transaction** --> (our DHCP
>>> server)
>>>     ^^---------------------------DHCP REPLY-----------------------^^
>>>
>>> So the endpoint customer, is trying to get a DHCP address which is
>>> passed
>>> through our wholesaler.  We then want to route a different range to
>>> the customer than what we have seen the address as:
>>>
>>> Currently the config sits at:
>>>
>>>
>>> subnet 203.***.***.0 netmask 255.255.255.0 {
>>> }
>>> subnet 58.***.***.0 netmask 255.0.0.0 {
>>>          ## dhcp start  and end IP range ##
>>>          range 14.***.***.2 14.***.***.253;
>>>          option subnet-mask 255.255.255.0;     ## subnet
>>>          option broadcast-address 14.***.***.255; ## broadcast
>>>          option routers 14.***.***.254; ## router IP
>>>
>>> }
>>>
>>> subnet 14.***.***.0 netmask 255.255.255.0 {
>>>          ## dhcp start  and end IP range ##
>>>          range 14.137.118.2 14.137.118.253;
>>>          option subnet-mask 255.255.255.0;     ## subnet
>>>          option broadcast-address 14.137.118.255; ## broadcast
>>>          option routers 14.137.118.254; ## router IP
>>> }
>>>
>>> Obviously this does not work and we are seeing the dhcp request being
>>> proxied
>>> through to us from a different subnet than the one we want to lease
>>> out.
>>>
>>>
>>> DHCPDISCOVER from a4:b1:e9:6c:10:34 via 58.***.***.194: network
>>> 58.***.***.0/24: no free leases
>>>
>>> I've change the configuration around and removed the 58.*** range, but
>>> get the following:
>>>
>>> DHCPDISCOVER from a4:b1:e9:6c:10:34 via 58.***.***.194: unknown
>>> network segment
>>>
>>>
>>> What do I need to change or do to allow any request coming through to
>>> hand out what range I specify?
>>>
>>> Any thoughts, help would be appreciated.
>>>
>>> Have been through google, but their is nothing that matches * similar*
>>> to what I need to do.  Perhaps I may not have had enough coffee yet as
>>> well :-)
>>>
>>> //Simon
>>> _______________________________________________
>>> dhcp-users mailing list
>>> dhcp-users at lists.isc.org
>>> https://lists.isc.org/mailman/listinfo/dhcp-users
>>>
>>
>>
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