Doesn't a MS client go for a new server after 87.5% of the lease if It can't
contact it's original server.
I got a resource kit collecting dust somewhere what page is that on I'd like
to look that up microsoft always seems to amaze me with there bugs.
Maybe you should e-mail them the RFC.
If you got a print out for the sniff I'd like to take a look at that too.
Duck
----- Original Message -----
From: Dale Holmes <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]>
Sent: Monday, September 11, 2000 10:10 AM
Subject: Re: Ip helper address
> Perhaps I should be more clear about this and say that this is the
behaviour
> of MICROSOFT DHCP clients. Here is the info from the Windows NT Resource
> kit:
>
> "Note: The client accepts the first offer it receives, regardless of
> whether the offer came from a DHCP server on the local subnet or from a
DHCP
> server on a different subnet. ... In the case where the DHCP server is
> unavailable or there is no available IP addressing information to lease to
a
> client computer, the client is unable to bind to TCP/IP."
>
> An MS DHCP client may receive many DHCPOFFER's for its DHCPDISCOVER
> broadcast. It will accept the first offer it receives (actually, the first
> response it gets), and NACK all others. If the first response it gets is
> negative, it will settle for that, and NACK anything from the other
servers.
> I have seen this (and sniffer traced it) in production. MS was unwilling
to
> call it a bug, and said the behaviour was by design and was RFC compliant.
> Case was closed...
>
> This was NT 4.0 Service pack 4 with Win98 clients. I dunno if they have
> changed things since, but I doubt it.
>
> Dale
> [=`)
>
>
>
>
> >From: "Donald B Johnson Jr" <[EMAIL PROTECTED]>
> >To: "Dale Holmes" <[EMAIL PROTECTED]>, <[EMAIL PROTECTED]>,
> ><[EMAIL PROTECTED]>
> >Subject: Re: Ip helper address
> >Date: Mon, 11 Sep 2000 12:36:49 -0700
> >
> >I don't understand this, wouldn't the client accept the second offer by
> >sending the seconds servers siaddr in the request packet. also DHCP
> >standard
> >says that nowhere must a client accept the first offer and then stop
> >broadcasting. All servers will answer the clients DHCPDISCOVER broadcast
> >with any help it can or can not offer. The first server does not tell the
> >second server to shutup so as soon as the (second or 1nanosecond slower
> >server) receives the broadcast it will it will send a DHCPOFFER packet
and
> >the client will reply with an DHCPREQUEST packet to the second server
> >(using the siaddr field) that will be ack'd by the second server with an
> >DHCPACK packet. This is all made quite clear in RFC 1541. So you can have
> >two DHCP servers on the same segment you just don't know which one will
> >serve the address to the client but both will try independent of each
other
> >and the client will ot stop trying after receiving after a nack from a
> >server.
> >Duck
> >----- Original Message -----
> >From: Dale Holmes <[EMAIL PROTECTED]>
> >To: <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]>
> >Sent: Friday, September 08, 2000 7:10 AM
> >Subject: Re: Ip helper address
> >
> >
> > >
> > > You have 2 DHCP servers on the same subnet??? This is probably not a
> >good
> > > idea... it does not really provide redundancy or load balancing.
> > > The DHCP client will issue a request and accept the first response
that
> >it
> > > gets.
> > >
> > > If you split your scope such that half of your available addresses are
> >on
> > > one server and half are on the other, you will *NOT* see that half of
> >your
> > > clients use one server while half use the other. If for some reason
one
> > > server always replies a nanosecond earlier than the other, then all
> >clients
> > > will accept the response from that server. Once that server is out of
> > > addresses, it will start sending nack's. The clients will start
> >accepting
> > > those nack's and will not request an address again, even though the
> >other
> > > DHCP server may have dozens of free addresses to offer.
> > >
> > > SO - in answer to your question, the ip helper address of 10.10.10.0
> >will
> > > allow your client's requests to reach all DHCP servers on that subnet,
> > > HOWEVER they will only accept leases from the first server from which
> >they
> > > receive a response. Chances are that server will be the same one all
the
> > > time, even after it runs out of addresses to offer...
> > >
> > > You *could* set up your DHCP servers such that the scope on EACH ONE
is
> > > sufficient to offer leases to ALL of you clients, but that is probably
a
> > > less than efficient use of your address space.
> > >
> > > I hope that this helps...
> > >
> > > Dale
> > > [=`)
> > >
> > > >From: "Dennis Bates" <[EMAIL PROTECTED]>
> > > >Reply-To: "Dennis Bates" <[EMAIL PROTECTED]>
> > > >To: [EMAIL PROTECTED]
> > > >Subject: Ip helper address
> > > >Date: Fri, 8 Sep 2000 08:10:44 -0500
> > > >
> > > >I am trying to put a statement on the remote router to allow the
> >clients
> >to
> > > >obtain an IP address accross the WAN. I have used the ip
> >helper-address
> > > >command successfully. My problem is that i would like any of the
DHCP
> > > >servers at the central site to be able to service DHCP requests from
> >the
> > > >remote site. Do I have to use mutilple ip helper-address statements
?
> >I
> > > >have tried a helper address pointing to the subnet, but that does
not
> >seem
> > > >to work. EX. i have DHCP servers at 10.10.10.10 and 10.10.10.11 do i
> >have
> > > >to
> > > >use two seperate ip helper address statements or can i use ip
> > > >helper-address
> > > >10.10.10.0 ?
> > > >
> > > >
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