Re: Multiple DHCP Servers
Keith Bailey <KeithB@keefb.demon.co.uk> wrote in
news:1QuSeSAavdQBFwIQ@keefb.demon.co.uk:
[color=blue]
> I have set up the DHCP server, the subnet & the address range to be
> different from the primary servers. I use the RFC1918 172.16.x.x. class
> B range. I have a DHCP server issuing addresses in the 172.16.1.0 subnet
> & I have set up another server to dispense addresses in the 172.16.4.0
> subnet. The server base IP address is not in this range.
>
> The server starts up fine but won't allocate any addresses. Running
> DHCPSRVR with the -d3 switch shows that it says "received packet from
> 172.16.0.0 subnet. Server is not configured to allocate addresses in
> this range".
>
> I saw in an old(ish) TID that the server base IP address had to be
> within the DHCP address range. Is this still true & is this why it's
> refusing to allocate addresses?[/color]
What subnet mask do you use?
If you use the class B subnet mask (255.255.0.0), it should work. If you
use 255.255.255.0, you must be having a router between the 172.16.1.0 net
and the 172.16.4.0 net. This router can most likely be configured to
forward DHCP requests to the DHCP server.
Remember the difference between subnets and subnet address ranges. You have
a subnet, and within this subnet you have an address range. For example,
you can reserve addresses 172.16.1.0-172.16.1.10 for routers, servers etc.,
and let the DCHP server hand out addresses 172.16.1.11-172.16.1.254 to
clients.
For redundance, you have two choices:
1. Have one server running, and another server configured, ready for a
manual switch.
2. Configure and run two DHCP servers. This is OK, as long as they don't
hand out from the same address range.
HTH,
Erik Klausen
Re: Multiple DHCP Servers
On Fri, 10 Sep 2004 18:37:41 +0000, Erik Klausen wrote:
[color=blue]
> Keith Bailey <KeithB@keefb.demon.co.uk> wrote in
> news:1QuSeSAavdQBFwIQ@keefb.demon.co.uk:
>[color=green]
>> I have set up the DHCP server, the subnet & the address range to be
>> different from the primary servers. I use the RFC1918 172.16.x.x. class
>> B range. I have a DHCP server issuing addresses in the 172.16.1.0 subnet
>> & I have set up another server to dispense addresses in the 172.16.4.0
>> subnet. The server base IP address is not in this range.
>>
>> The server starts up fine but won't allocate any addresses. Running
>> DHCPSRVR with the -d3 switch shows that it says "received packet from
>> 172.16.0.0 subnet. Server is not configured to allocate addresses in
>> this range".
>>
>> I saw in an old(ish) TID that the server base IP address had to be
>> within the DHCP address range. Is this still true & is this why it's
>> refusing to allocate addresses?[/color]
>
> What subnet mask do you use?
> If you use the class B subnet mask (255.255.0.0), it should work. If you
> use 255.255.255.0, you must be having a router between the 172.16.1.0 net
> and the 172.16.4.0 net. This router can most likely be configured to
> forward DHCP requests to the DHCP server.
>
> Remember the difference between subnets and subnet address ranges. You have
> a subnet, and within this subnet you have an address range. For example,
> you can reserve addresses 172.16.1.0-172.16.1.10 for routers, servers etc.,
> and let the DCHP server hand out addresses 172.16.1.11-172.16.1.254 to
> clients.
>
> For redundance, you have two choices:
> 1. Have one server running, and another server configured, ready for a
> manual switch.
>
> 2. Configure and run two DHCP servers. This is OK, as long as they don't
> hand out from the same address range.
>
> HTH,
> Erik Klausen[/color]
Sounds like a job for Cluster Services (if you use it). Just add
the dhcpsrvr as a cluster resource and forget about it.
Cheers
Alex
Netware Geek
Leeds Met University
Re: Multiple DHCP Servers
Erik,
Thanks for the reply. I use 255.255.248 as the subnet mask & I am using,
in effect, a class C address range (254 addreses). The range is within
the server subnet mask but the server's IP address is outside the range
that I want the DHCP server to dispense.
In article <Xns9560D1D8EEB33ErikKlausen@62.243.74.162>, Erik Klausen
<ekl@host.domain> writes[color=blue]
>Keith Bailey <KeithB@keefb.demon.co.uk> wrote in
>news:1QuSeSAavdQBFwIQ@keefb.demon.co.uk:
>[color=green]
>> I have set up the DHCP server, the subnet & the address range to be
>> different from the primary servers. I use the RFC1918 172.16.x.x. class
>> B range. I have a DHCP server issuing addresses in the 172.16.1.0 subnet
>> & I have set up another server to dispense addresses in the 172.16.4.0
>> subnet. The server base IP address is not in this range.
>>
>> The server starts up fine but won't allocate any addresses. Running
>> DHCPSRVR with the -d3 switch shows that it says "received packet from
>> 172.16.0.0 subnet. Server is not configured to allocate addresses in
>> this range".
>>
>> I saw in an old(ish) TID that the server base IP address had to be
>> within the DHCP address range. Is this still true & is this why it's
>> refusing to allocate addresses?[/color]
>
>What subnet mask do you use?
>If you use the class B subnet mask (255.255.0.0), it should work. If you
>use 255.255.255.0, you must be having a router between the 172.16.1.0 net
>and the 172.16.4.0 net. This router can most likely be configured to
>forward DHCP requests to the DHCP server.
>
>Remember the difference between subnets and subnet address ranges. You have
>a subnet, and within this subnet you have an address range. For example,
>you can reserve addresses 172.16.1.0-172.16.1.10 for routers, servers etc.,
>and let the DCHP server hand out addresses 172.16.1.11-172.16.1.254 to
>clients.
>
>For redundance, you have two choices:
>1. Have one server running, and another server configured, ready for a
>manual switch.
>
>2. Configure and run two DHCP servers. This is OK, as long as they don't
>hand out from the same address range.
>
>HTH,
>Erik Klausen[/color]
Keith Bailey
Computer Manager
Kingsbury High School
LONDON UK
Re: Multiple DHCP Servers
Keith Bailey <KeithB@keefb.demon.co.uk> wrote in
news:ZfjpNpArNCRBFw1T@keefb.demon.co.uk:
[color=blue]
> Erik,
>
> Thanks for the reply. I use 255.255.248 as the subnet mask & I am
> using, in effect, a class C address range (254 addreses). The range is
> within the server subnet mask but the server's IP address is outside
> the range that I want the DHCP server to dispense.[/color]
It shouldn't be a problem. I use a 255.255.128.0-subnet mask, my DHCP-
server's address is in the 10.16.32.0-range, and it hands out addresses in
10.16.110.0-range.
In DHCP, I assume you have created a subnet, and within this subnet you
have a subnet address range? The subnet address range is the pool of
addresses that the server hands out. Also, the DHCP server should be
assigned to the subnet.
If te DHCP environment is configured, check that the MAC address of the
computer being rejected, isn't already in the DHCP database. If it is,
delete it.
This shouldn't be a problem, but then again, this is computer business :-)
Erik Klausen
