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Today's Topics:
1. Re: DISCOVERs from "unkown network segment" - suppress log
messages? (Simon)
2. Re: DISCOVERs from "unkown network segment" - suppress log
messages? (Christina Siegenthaler)
3. Re: DISCOVERs from "unkown network segment" - suppress log
messages? (Christina Siegenthaler)
----------------------------------------------------------------------
Message: 1
Date: Tue, 29 Nov 2022 16:23:36 +0000
From: Simon <dh...@thehobsons.co.uk>
To: Users of ISC DHCP <dhcp-users@lists.isc.org>
Subject: Re: DISCOVERs from "unkown network segment" - suppress log
messages?
Message-ID: <bda3e5f0-df10-42dc-af08-6016107e9...@thehobsons.co.uk>
Content-Type: text/plain; charset=utf-8
Christina Siegenthaler <t...@ieu.uzh.ch> wrote:
> Since I know that the rogue client is supposed to get a fixed IP address (and
> which one), I added a pool to that subnet declaration containing just this
> one IP, plus a host declaration for the rogue client with a ?fixed-address?
> statement giving it the fixed IP it?s supposed to get from the other DHCP
> server, plus, just to be safe, an "ignore booting" statement as well.
>
>
> Looks like this:
>
>
> ####################
> # Ignore these
> ####################
>
> subnet 10.65.xx.0 netmask 255.255.254.0 {
> pool { range 10.65.xx.61 10.65.xx.61;
> ignore booting; }
> }
>
> host ignore_me_1 { hardware ethernet 00:07:32:xx:xx:xx; ignore booting;
> fixed-address 10.65.xx.61; }
Being pedantic, you don?t need the pool - and in the general case, you should
NOT have any fixed-address assignment which is also in any pool. If you do,
then it?s entirely possible to hand out the address dynamically to one client,
and also via the host declaration to another - causing some ?interesting?
effects in the network.
This should be sufficient :
subnet 10.65.xx.0 netmask 255.255.254.0 {
ignore booting;
}
host ignore_me_1 { hardware ethernet 00:07:32:xx:xx:xx; ignore booting;
fixed-address 10.65.xx.61; }
Simon
------------------------------
Message: 2
Date: Wed, 30 Nov 2022 07:53:41 +0000
From: Christina Siegenthaler <t...@ieu.uzh.ch>
To: Users of ISC DHCP <dhcp-users@lists.isc.org>
Subject: Re: DISCOVERs from "unkown network segment" - suppress log
messages?
Message-ID: <e2bf970c-ee1c-4552-aabf-f83898bba...@ieu.uzh.ch>
Content-Type: text/plain; charset="utf-8"
Am 29.11.2022 um 17:23 schrieb Simon <dh...@thehobsons.co.uk>:
>
> Christina Siegenthaler <t...@ieu.uzh.ch> wrote:
>
>> Since I know that the rogue client is supposed to get a fixed IP address
>> (and which one), I added a pool to that subnet declaration containing just
>> this one IP, plus a host declaration for the rogue client with a
>> ?fixed-address? statement giving it the fixed IP it?s supposed to get from
>> the other DHCP server, plus, just to be safe, an "ignore booting" statement
>> as well.
>>
>>
>> Looks like this:
>>
>>
>> ####################
>> # Ignore these
>> ####################
>>
>> subnet 10.65.xx.0 netmask 255.255.254.0 {
>> pool { range 10.65.xx.61 10.65.xx.61;
>> ignore booting; }
>> }
>>
>> host ignore_me_1 { hardware ethernet 00:07:32:xx:xx:xx; ignore booting;
>> fixed-address 10.65.xx.61; }
>
> Being pedantic, you don?t need the pool - and in the general case, you should
> NOT have any fixed-address assignment which is also in any pool. If you do,
> then it?s entirely possible to hand out the address dynamically to one
> client, and also via the host declaration to another - causing some
> ?interesting? effects in the network.
>
> This should be sufficient :
> subnet 10.65.xx.0 netmask 255.255.254.0 {
> ignore booting;
> }
> host ignore_me_1 { hardware ethernet 00:07:32:xx:xx:xx; ignore booting;
> fixed-address 10.65.xx.61; }
You?re right, of course, I don?t know what I was thinking? I removed the pool
and it still works fine, no messages are logged for this particular host.
However, it does not work without the ?fixed-address? statement, because in
this case, I?ll get a message saying ?no free leases?; ?ignore booting? in the
subnet and/or host declaration alone clearly does not suffice.
And thus, all other hosts in that subnet still show with either that (in case
of DISCOVERs) or ?unknown lease? (REQUEST). Would have been nice to get rid of
those, too, especially since the REQUESTs are being sent every 10mins per
client, even though the DHCP admin says their default lease time is 4h. Oh my.
Tina
>
>
> Simon
>
> --
> ISC funds the development of this software with paid support subscriptions.
> Contact us at https://www.isc.org/contact/ for more information.
>
> dhcp-users mailing list
> dhcp-users@lists.isc.org
> https://lists.isc.org/mailman/listinfo/dhcp-users
------------------------------
Message: 3
Date: Wed, 30 Nov 2022 08:33:04 +0000
From: Christina Siegenthaler <t...@ieu.uzh.ch>
To: Users of ISC DHCP <dhcp-users@lists.isc.org>
Subject: Re: DISCOVERs from "unkown network segment" - suppress log
messages?
Message-ID: <a0ccbd9f-d1d1-4bd2-93dc-9b02106cb...@ieu.uzh.ch>
Content-Type: text/plain; charset="utf-8"
>>
>> Being pedantic, you don?t need the pool - and in the general case, you
>> should NOT have any fixed-address assignment which is also in any pool. If
>> you do, then it?s entirely possible to hand out the address dynamically to
>> one client, and also via the host declaration to another - causing some
>> ?interesting? effects in the network.
>>
>> This should be sufficient :
>> subnet 10.65.xx.0 netmask 255.255.254.0 {
>> ignore booting;
>> }
>> host ignore_me_1 { hardware ethernet 00:07:32:xx:xx:xx; ignore booting;
>> fixed-address 10.65.xx.61; }
>
>
> You?re right, of course, I don?t know what I was thinking? I removed the
> pool and it still works fine, no messages are logged for this particular
> host. However, it does not work without the ?fixed-address? statement,
> because in this case, I?ll get a message saying ?no free leases?; ?ignore
> booting? in the subnet and/or host declaration alone clearly does not suffice.
>
> And thus, all other hosts in that subnet still show with either that (in case
> of DISCOVERs) or ?unknown lease? (REQUEST). Would have been nice to get rid
> of those, too, especially since the REQUESTs are being sent every 10mins per
> client, even though the DHCP admin says their default lease time is 4h. Oh my.
>
>
I just noticed that since I added that subnet declaration, my DHCP server,
though it ignores DISCOVERs and REQUESTs, has started to answer to INFORMs in
that subnet - could that be a problem?
Tina
------------------------------
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End of dhcp-users Digest, Vol 169, Issue 16
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