Welcome Serena Central users! CLICK HERE
The migration of the Serena Central community is currently underway. Be sure to read THIS MESSAGE to get your new login set up to access your account.
Anonymous_User Absent Member.
Absent Member.
2914 views

1 DHCP server servicing several vlans

Hello,

I have a school that has about 10 computer labs. I would like to create a
vlan for each of these 10 computer labs. I want to vlan each of these labs
so that each lab has a subnet of /26. (255.255.255.192).

My concern with this is how to get dhcp to work in a vlanned envrironment.
How can I configure dhcp on my Netware 6.5 server to service say about 11
different subnets, and lease the correct subnet to the correct vlans?
Currently, I am leasing 3 subnets, however, it is all one vlan.

Jared H.


Labels (1)
0 Likes
12 Replies
Anonymous_User Absent Member.
Absent Member.

Re: 1 DHCP server servicing several vlans

Just create the DHCP segments for the DHCP server. Nothing more needed
on the Novell server.

What you do need to do is configure the router for a DHCP helper
address. This tells the router to forward the DHCP request to a
specific IP addy.

--
Timothy Leerhoff
Novell Support Forum Volunteer Sysop
0 Likes
Anonymous_User Absent Member.
Absent Member.

Re: 1 DHCP server servicing several vlans

So, I need to create my differnet subnet objects and the corresponding
address ranges. I would also have to have each subnet bound to the server,
correct?

Jared H.


"Timothy Leerhoff" <tleerhoffNO@SPAMqwest.net> wrote in message
news:zptpe.2754$hY.1790@prv-forum2.provo.novell.com...
> Just create the DHCP segments for the DHCP server. Nothing more needed
> on the Novell server.
>
> What you do need to do is configure the router for a DHCP helper
> address. This tells the router to forward the DHCP request to a
> specific IP addy.
>
> --
> Timothy Leerhoff
> Novell Support Forum Volunteer Sysop



0 Likes
Anonymous_User Absent Member.
Absent Member.

Re: 1 DHCP server servicing several vlans

> So, I need to create my differnet subnet objects and the
> corresponding address ranges.


Yes.

> I would also have to have each subnet
> bound to the server, correct?


No. The router will get the dhcp request to the server's IP thanks to
the DHCP helper address (Cisco's name for it).

--
Timothy Leerhoff
Novell Support Forum Volunteer Sysop
0 Likes
Anonymous_User Absent Member.
Absent Member.

Re: 1 DHCP server servicing several vlans

all of my vlans will not be going through a router, they will be going
through a layer 3 foundry switch.

Jared H.

"Timothy Leerhoff" <tleerhoffNO@SPAMqwest.net> wrote in message
news:l8Ppe.3865$hY.952@prv-forum2.provo.novell.com...
>> So, I need to create my differnet subnet objects and the
>> corresponding address ranges.

>
> Yes.
>
>> I would also have to have each subnet
>> bound to the server, correct?

>
> No. The router will get the dhcp request to the server's IP thanks to
> the DHCP helper address (Cisco's name for it).
>
> --
> Timothy Leerhoff
> Novell Support Forum Volunteer Sysop



0 Likes
Anonymous_User Absent Member.
Absent Member.

Re: 1 DHCP server servicing several vlans

> all of my vlans will not be going through a router, they will be
> going through a layer 3 foundry switch.


They should still have a routing engine in them. Theory is still the
same regardless of what does the routing. You will need to add the
DHCP helper address to the item routing between segments/VLANs. The
helper is the IP of the DHCP server.

--
Timothy Leerhoff
Novell Support Forum Volunteer Sysop
0 Likes
Anonymous_User Absent Member.
Absent Member.

Re: 1 DHCP server servicing several vlans

Actually, our situation is very similar to the above. We have only one
DHCP server and we have divided our whole school network to a total of 3
VLANs with 3 three different IP subnet range. We are using the Cisco
3560G layer 3 switch to perform the routing between the three VLANs.
However, we found that the workstations in VLAN 2 and VLAN 3 cannot login
properly during the first time. What we need to do is to use
the "workstation only" option (Windows XP) to login to the workstation
and try to manually release and renew the IP address (ipconfig /release -
> ipconfig /renew), the stange thing is that when I perform

the "release / renew" for the first time, I can get VLAN2's IP address,
when I do it the second time, I will get "192.168.x.x", then I do the
third time, I can get the correct IP address. When I put the machine to
the same subnet as the DHCP server, everything is fine and fast for the
whole login process. Any ideas about this strange situation ?? Any
suggestions will really help. Thanks !

Alvin


> > all of my vlans will not be going through a router, they will be
> > going through a layer 3 foundry switch.

>
> They should still have a routing engine in them. Theory is still the
> same regardless of what does the routing. You will need to add the
> DHCP helper address to the item routing between segments/VLANs. The
> helper is the IP of the DHCP server.
>
> --
> Timothy Leerhoff
> Novell Support Forum Volunteer Sysop


0 Likes
Anonymous_User Absent Member.
Absent Member.

Re: 1 DHCP server servicing several vlans

In article <YAyte.2091$5l3.283@prv-forum2.provo.novell.com>, wrote:
> We are using the Cisco
> 3560G layer 3 switch to perform the routing between the three VLANs.
>

Have you entered an IP Helper address into the config for that device.
You'll need to do that once per VLAN which is not the DHCP server's
VLAN.

From the rest of your description, it sounds like broadcasts are being
forwarded by the switch across VLANs?

bd
NSC Volunteer SysOp


0 Likes
Anonymous_User Absent Member.
Absent Member.

Re: 1 DHCP server servicing several vlans

I agree with Brad that the probable issue is not having the IPHelper
address setup for the VLans remote to the DHCP server.

IIRC This is entered for the interface configuration (same interface
that has the default route IP) for that VLAN.

--
Timothy Leerhoff
Novell Support Forum Volunteer Sysop

The future comes slowly, the present flies and the past stands still
forever
0 Likes
Anonymous_User Absent Member.
Absent Member.

Re: 1 DHCP server servicing several vlans

Thank you for both your information.

Do you mean that we need to setup the IP address of the DHCP server in
each VLAN ?? Actually, I believe that our vendor has already done that
because we have assigned a total of 3 blocks to be in VLAN 2 (which is
done by setting up the ports of the switches for connecting those blocks
to the corresponding VLAN number) and two of the blocks can login properly
during the first time (Even still have some delays), but the remaining
block cannot even find out the tree and context and we need to login
locally to renew the IP address and finally login inside the Windows XP
desktop. So I really have headache about this problem. Any ideas ?? Brad
and Tim ?? Many Thanks !

Alvin


> I agree with Brad that the probable issue is not having the IPHelper
> address setup for the VLans remote to the DHCP server.
>
> IIRC This is entered for the interface configuration (same interface
> that has the default route IP) for that VLAN.
>
> --
> Timothy Leerhoff
> Novell Support Forum Volunteer Sysop
>
> The future comes slowly, the present flies and the past stands still
> forever


0 Likes
Anonymous_User Absent Member.
Absent Member.

Re: 1 DHCP server servicing several vlans

In article <82Cte.2338$5l3.1651@prv-forum2.provo.novell.com>, wrote:
> Actually, I believe that our vendor has already done
>

Still worth double-checking... if I am right about broadcasts being
passed across VLANs (unusual but possible), this could explain some of
the behavior you're seeing, including the delayed, but successful
connections. Either way, the more you tell us, the more it sounds like
something in the switch is not configured properly.

bd
NSC Volunteer SysOp


0 Likes
Anonymous_User Absent Member.
Absent Member.

Re: 1 DHCP server servicing several vlans

Thanks Brad.
Since we have changed from a single IP range (172.16.x.x) to 3 new IP
ranges (172.16.x.x, 172.21.x.x, 172.26.x.x), I just think that there may
be a possibility that the workstations and print servers (e.g. NetPort)
still using the old IP address ranges. But I have no ideas why the
workstations in another subnet (which is not the same as the DHCP server
located) have the IP ranges 192.168.11.x assigned to them.

Any suggestions ?

Alvin

> In article <82Cte.2338$5l3.1651@prv-forum2.provo.novell.com>, wrote:
> > Actually, I believe that our vendor has already done
> >

> Still worth double-checking... if I am right about broadcasts being
> passed across VLANs (unusual but possible), this could explain some of
> the behavior you're seeing, including the delayed, but successful
> connections. Either way, the more you tell us, the more it sounds like
> something in the switch is not configured properly.
>
> bd
> NSC Volunteer SysOp
>
>


0 Likes
Anonymous_User Absent Member.
Absent Member.

Re: 1 DHCP server servicing several vlans

In article <%fLte.2760$5l3.462@prv-forum2.provo.novell.com>, wrote:
> But I have no ideas why the
> workstations in another subnet (which is not the same as the DHCP server
> located) have the IP ranges 192.168.11.x assigned to them.
>

Well, you mentioned that address range before, but you never said it was an
incorrect range. And if it is, then one of 2 possibilities come to mind...

There is another DHCP server on your network. When you get one of these
addresses, run IPCONFIG /ALL from a command prompt on the workstation --
does it show a DHCP server address?

Or, with XP, it is possible to set a statically configured alternate IP
address, to be used if a DHCP address cannot be obtained.

bd
NSC Volunteer SysOp


0 Likes
The opinions expressed above are the personal opinions of the authors, not of Micro Focus. By using this site, you accept the Terms of Use and Rules of Participation. Certain versions of content ("Material") accessible here may contain branding from Hewlett-Packard Company (now HP Inc.) and Hewlett Packard Enterprise Company. As of September 1, 2017, the Material is now offered by Micro Focus, a separately owned and operated company. Any reference to the HP and Hewlett Packard Enterprise/HPE marks is historical in nature, and the HP and Hewlett Packard Enterprise/HPE marks are the property of their respective owners.