windows nt dhcp server problem

G

Guest

Guest
Archived from groups: microsoft.public.windowsnt.domain (More info?)

hi, we have a windows nt 4 running as a PDC and DHCP server. we have about 60
computers on the network running win95, 98 and 2000. We have a Linux email
server too.

Occasionally, and seemingly randomly some machines are not being assigned a
gateway address (the ip points to the linux server), but they do get the
normal ip and subnet. This stops the email working until i go over to the
machine that is having the problem and do an ipconfig /release followed by a
renew.

Is there any known bug that could cause this???

Thanks, Rick
 
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Guest
Archived from groups: microsoft.public.windowsnt.domain (More info?)

The linux server is routing the clients to the internet?
When the problem occurs have you tested connectivity
between the client and linux server e.g., ping by tcp/ip
address?

"Rick T" <RickT@discussions.microsoft.com> wrote in message news:
> hi, we have a windows nt 4 running as a PDC and DHCP server. we have
about 60
> computers on the network running win95, 98 and 2000. We have a Linux
email
> server too.
>
> Occasionally, and seemingly randomly some machines are not being
assigned a
> gateway address (the ip points to the linux server), but they do get
the
> normal ip and subnet. This stops the email working until i go over to
the
> machine that is having the problem and do an ipconfig /release
followed by a
> renew.
>
> Is there any known bug that could cause this???
 
G

Guest

Guest
Archived from groups: microsoft.public.windowsnt.domain (More info?)

Hi, yes we have checked connectivity and it appears to be fine, the rest of
the machines on the network continue without problem too.

Rick

"Michael Giorgio - MS MVP" wrote:

> The linux server is routing the clients to the internet?
> When the problem occurs have you tested connectivity
> between the client and linux server e.g., ping by tcp/ip
> address?
>
> "Rick T" <RickT@discussions.microsoft.com> wrote in message news:
> > hi, we have a windows nt 4 running as a PDC and DHCP server. we have
> about 60
> > computers on the network running win95, 98 and 2000. We have a Linux
> email
> > server too.
> >
> > Occasionally, and seemingly randomly some machines are not being
> assigned a
> > gateway address (the ip points to the linux server), but they do get
> the
> > normal ip and subnet. This stops the email working until i go over to
> the
> > machine that is having the problem and do an ipconfig /release
> followed by a
> > renew.
> >
> > Is there any known bug that could cause this???
>
>
>
 
G

Guest

Guest
Archived from groups: microsoft.public.windowsnt.domain (More info?)

Okay so you run ipconfig /all on the client and the gateway
is blank? The only thing I can think of that would this is
Dead Default Gateway Detection.


"Rick T" <RickT@discussions.microsoft.com> wrote in message news:
> Hi, yes we have checked connectivity and it appears to be fine, the
rest of
> the machines on the network continue without problem too.
 
G

Guest

Guest
Archived from groups: microsoft.public.windowsnt.domain (More info?)

Hi, thanks for the reply.

The gateway is definately there, but could it be that the machine acting as
the gateway is not responding in time?? What is the delay before the gateway
detection decides it is not there? How many retries will it do before giving
up?

The only other thing I can think of is that we have a second server at our
other site, which is connected to our network over a 64k leased line, this
server is identical to our local server and acts as a BDC, and it also acts
as a dhcp server for the other site. As they do not use a gateway their dhcp
does not supply the machines with a gateway address. Could it be that this
server is responding quicker than our local server and so supplying an ip
with no gateway?? I would find this unlikely because of the fact it is
connected via a very slow line and the system has been in place for over a
year without any problems like this occuring before, but is it possible.

I have now set the server at the other site to give out the gateway address
too, to see if this helps, and so far have not had any problems, but because
this problem is random i do not know for sure if it has fixed it.

Do you or anyone else know if it is possible to discover whereabouts the
client machine has obtained its ip from (i.e. which of the two servers has
assigned the address)???

Thank you

Rick

"Michael Giorgio - MS MVP" wrote:

> Okay so you run ipconfig /all on the client and the gateway
> is blank? The only thing I can think of that would this is
> Dead Default Gateway Detection.
>
>
> "Rick T" <RickT@discussions.microsoft.com> wrote in message news:
> > Hi, yes we have checked connectivity and it appears to be fine, the
> rest of
> > the machines on the network continue without problem too.
>
>
>
 
G

Guest

Guest
Archived from groups: microsoft.public.windowsnt.domain (More info?)

Hi Rick,

The second one makes sense. Actually I was thinking maybe
perhaps a rogue DHCP server that is assiging the address
without the gateway. Are you saying the tcp/ip address range
is the same for each?
"Rick T" <RickT@discussions.microsoft.com> wrote in message news:
> Hi, thanks for the reply.
>
> The gateway is definately there, but could it be that the machine
acting as
> the gateway is not responding in time?? What is the delay before the
gateway
> detection decides it is not there? How many retries will it do before
giving
> up?
>
> The only other thing I can think of is that we have a second server at
our
> other site, which is connected to our network over a 64k leased line,
this
> server is identical to our local server and acts as a BDC, and it also
acts
> as a dhcp server for the other site. As they do not use a gateway
their dhcp
> does not supply the machines with a gateway address. Could it be that
this
> server is responding quicker than our local server and so supplying an
ip
> with no gateway?? I would find this unlikely because of the fact it is
> connected via a very slow line and the system has been in place for
over a
> year without any problems like this occuring before, but is it
possible.
>
> I have now set the server at the other site to give out the gateway
address
> too, to see if this helps, and so far have not had any problems, but
because
> this problem is random i do not know for sure if it has fixed it.
>
> Do you or anyone else know if it is possible to discover whereabouts
the
> client machine has obtained its ip from (i.e. which of the two servers
has
> assigned the address)???
>
> Thank you
>
> Rick
>
> "Michael Giorgio - MS MVP" wrote:
>
> > Okay so you run ipconfig /all on the client and the gateway
> > is blank? The only thing I can think of that would this is
> > Dead Default Gateway Detection.
> >
> >
> > "Rick T" <RickT@discussions.microsoft.com> wrote in message news:
> > > Hi, yes we have checked connectivity and it appears to be fine,
the
> > rest of
> > > the machines on the network continue without problem too.
> >
> >
> >
 
G

Guest

Guest
Archived from groups: microsoft.public.windowsnt.domain (More info?)

Hi, yes the ip ranges are the same, it is just the second server did not
supply a gateway address. Since changing this I have not had any more
problems so with any luck that is what caused the problem. I will leave it
for a couple of days before I can say that for sure though!

Just need to find out why it is doing it though if this is the case, I doubt
we have too much traffic on the server, and it is still a reasonably powerful
server given the fact we only have about 60 clients (duel 1 gig xeons, 1 gig
ram, network seperated with about 6 netgear switches etc etc)

Thanks for the help, appreciate it!

Rick

"Michael Giorgio - MS MVP" wrote:

> Hi Rick,
>
> The second one makes sense. Actually I was thinking maybe
> perhaps a rogue DHCP server that is assiging the address
> without the gateway. Are you saying the tcp/ip address range
> is the same for each?
> "Rick T" <RickT@discussions.microsoft.com> wrote in message news:
> > Hi, thanks for the reply.
> >
> > The gateway is definately there, but could it be that the machine
> acting as
> > the gateway is not responding in time?? What is the delay before the
> gateway
> > detection decides it is not there? How many retries will it do before
> giving
> > up?
> >
> > The only other thing I can think of is that we have a second server at
> our
> > other site, which is connected to our network over a 64k leased line,
> this
> > server is identical to our local server and acts as a BDC, and it also
> acts
> > as a dhcp server for the other site. As they do not use a gateway
> their dhcp
> > does not supply the machines with a gateway address. Could it be that
> this
> > server is responding quicker than our local server and so supplying an
> ip
> > with no gateway?? I would find this unlikely because of the fact it is
> > connected via a very slow line and the system has been in place for
> over a
> > year without any problems like this occuring before, but is it
> possible.
> >
> > I have now set the server at the other site to give out the gateway
> address
> > too, to see if this helps, and so far have not had any problems, but
> because
> > this problem is random i do not know for sure if it has fixed it.
> >
> > Do you or anyone else know if it is possible to discover whereabouts
> the
> > client machine has obtained its ip from (i.e. which of the two servers
> has
> > assigned the address)???
> >
> > Thank you
> >
> > Rick
> >
> > "Michael Giorgio - MS MVP" wrote:
> >
> > > Okay so you run ipconfig /all on the client and the gateway
> > > is blank? The only thing I can think of that would this is
> > > Dead Default Gateway Detection.
> > >
> > >
> > > "Rick T" <RickT@discussions.microsoft.com> wrote in message news:
> > > > Hi, yes we have checked connectivity and it appears to be fine,
> the
> > > rest of
> > > > the machines on the network continue without problem too.
> > >
> > >
> > >
>
>
>
 
G

Guest

Guest
Archived from groups: microsoft.public.windowsnt.domain (More info?)

A client will send a DHCP discovery packet to find a DHCP
server and there is no telling which server will respond with an
address. I asked you if they were in the same range meaning
handing the same tcp/ip range of addresses and you responded
with a yes but I can't see how that doesn't cause you problems.
Can we assume the ranges aren't overlapping?

"Rick T" <RickT@discussions.microsoft.com> wrote in message news:
> Hi, yes the ip ranges are the same, it is just the second server did
not
> supply a gateway address. Since changing this I have not had any more
> problems so with any luck that is what caused the problem. I will
leave it
> for a couple of days before I can say that for sure though!
>
> Just need to find out why it is doing it though if this is the case, I
doubt
> we have too much traffic on the server, and it is still a reasonably
powerful
> server given the fact we only have about 60 clients (duel 1 gig xeons,
1 gig
> ram, network seperated with about 6 netgear switches etc etc)
>
> Thanks for the help, appreciate it!
 
G

Guest

Guest
Archived from groups: microsoft.public.windowsnt.domain (More info?)

Hi Michael,

Both the servers supply the address in the range 10.0.0.101 to 10.0.0.254

I too was a little confused as to how this works, I have only been with the
company for about 4 months and this was already in place when i started, but
it seems to work somehow! The DHCP manager does show quite a few bad address
warnings, so presumably this is due to ip conflicts.

I guess the fact we only have a few machines at the second site is the
reason we have not had any problems with this setup, if there were more
machines then it would obviously cause real issues. I wonder though, does the
second NT server at the second site (which is acting as a BDC) check the
first server to see if the IP addresses are available???

Thanks for the help

Rick

"Michael Giorgio - MS MVP" wrote:

> A client will send a DHCP discovery packet to find a DHCP
> server and there is no telling which server will respond with an
> address. I asked you if they were in the same range meaning
> handing the same tcp/ip range of addresses and you responded
> with a yes but I can't see how that doesn't cause you problems.
> Can we assume the ranges aren't overlapping?
>
> "Rick T" <RickT@discussions.microsoft.com> wrote in message news:
> > Hi, yes the ip ranges are the same, it is just the second server did
> not
> > supply a gateway address. Since changing this I have not had any more
> > problems so with any luck that is what caused the problem. I will
> leave it
> > for a couple of days before I can say that for sure though!
> >
> > Just need to find out why it is doing it though if this is the case, I
> doubt
> > we have too much traffic on the server, and it is still a reasonably
> powerful
> > server given the fact we only have about 60 clients (duel 1 gig xeons,
> 1 gig
> > ram, network seperated with about 6 netgear switches etc etc)
> >
> > Thanks for the help, appreciate it!
>
>
>