| Author |
Using DHCP across VLANs
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| -Auto- 2004-04-01, 6:25 pm |
| Have a Catalyst 4006 w/Sup III+ engine (Native
IOS). Switch is configured with Vlans 1, 10,
20, 30.
Vlan 1 = management
Vlan 10 = Servers
Vlan 20 = Printers
Vlan 30 = Clients
IP routing is enabled.
Each vlan interface is configured with a different
subnet: vlan 10 = .224.0/25, vlan 20 = .224.128/25
and vlan 30 = .225.0/24
Hosts on vlan's 10 and 20 are static IP'd.
The DHCP server resides in Vlan 10 with
a .224.xx/25 address. However all of the clients
in Vlan 30 need to draw .225/24 IPs from the
DHCP server residing in Vlan 10.
Will the DHCP broadcasts traverse the vlans without
further configuration or must I do something more?
Research indicates routers will not automatically
forward DHCP broadcasts. However I'm routing
within the switch.
Read/google'd about Boot relay and DHCP but nothing
talks to getting DHCP across vlans like I'm trying to
do.
Any ideas?
THanks.
Auto
| |
| Hansang Bae 2004-04-02, 1:25 am |
| In article <L01bc.8213$pM1.3784@lakeread06>, auto@nospam.com says...
> Have a Catalyst 4006 w/Sup III+ engine (Native
> IOS). Switch is configured with Vlans 1, 10,
> 20, 30.
[snip]
Is this a L3 switch? If so, you need to configure helper addresses.
See: http://www.cisco.com/warp/public/473/winnt_dg.htm (search for dhcp
relay)
--
hsb
"Somehow I imagined this experience would be more rewarding" Calvin
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| Steve Burton 2004-04-02, 8:24 pm |
| If its a layer three switch add the following on the Vlan interface where
the clients need to reach the DHCP server:
Interface Vlan30
ip helper-address xxx.xxx.xxx.xxx
Where xxx.xxx.xxx.xxx is the IP address of your DHCP Server on Vlan10.
If the Vlan Interface does not exist you will have to create it and
configure it.
Steve.
"-Auto-" <auto@nospam.com> wrote in message
news:L01bc.8213$pM1.3784@lakeread06...
> Have a Catalyst 4006 w/Sup III+ engine (Native
> IOS). Switch is configured with Vlans 1, 10,
> 20, 30.
>
> Vlan 1 = management
> Vlan 10 = Servers
> Vlan 20 = Printers
> Vlan 30 = Clients
>
> IP routing is enabled.
>
> Each vlan interface is configured with a different
> subnet: vlan 10 = .224.0/25, vlan 20 = .224.128/25
> and vlan 30 = .225.0/24
>
> Hosts on vlan's 10 and 20 are static IP'd.
>
> The DHCP server resides in Vlan 10 with
> a .224.xx/25 address. However all of the clients
> in Vlan 30 need to draw .225/24 IPs from the
> DHCP server residing in Vlan 10.
>
> Will the DHCP broadcasts traverse the vlans without
> further configuration or must I do something more?
> Research indicates routers will not automatically
> forward DHCP broadcasts. However I'm routing
> within the switch.
>
> Read/google'd about Boot relay and DHCP but nothing
> talks to getting DHCP across vlans like I'm trying to
> do.
>
> Any ideas?
>
> THanks.
>
> Auto
>
>
| |
| - Auto - 2004-04-03, 10:25 am |
|
"Steve Burton" <steveburton@nf.sympatico.ca> wrote in message
news:Omnbc.8844$Np3.293253@ursa-nb00s0.nbnet.nb.ca...
> If its a layer three switch add the following on the Vlan interface where
> the clients need to reach the DHCP server:
> Interface Vlan30
> ip helper-address xxx.xxx.xxx.xxx
>
> Where xxx.xxx.xxx.xxx is the IP address of your DHCP Server on Vlan10.
>
> If the Vlan Interface does not exist you will have to create it and
> configure it.
>
> Steve.
Thanks Steve! Yes it's a layer 3 switch and all the vlan interfaces
are configured with IP addresses. Will use the info you've
provided.
| |
|
| make sure you have service dhcp enabled as well.
Jimmy
"Steve Burton" <steveburton@nf.sympatico.ca> wrote in message
news:Omnbc.8844$Np3.293253@ursa-nb00s0.nbnet.nb.ca...
> If its a layer three switch add the following on the Vlan interface where
> the clients need to reach the DHCP server:
> Interface Vlan30
> ip helper-address xxx.xxx.xxx.xxx
>
> Where xxx.xxx.xxx.xxx is the IP address of your DHCP Server on Vlan10.
>
> If the Vlan Interface does not exist you will have to create it and
> configure it.
>
> Steve.
>
>
>
> "-Auto-" <auto@nospam.com> wrote in message
> news:L01bc.8213$pM1.3784@lakeread06...
>
>
| |
| Steve Burton 2004-04-09, 5:25 pm |
| Not required.
"Jimmy" <jimmy@the-dorans.com> wrote in message
news:c54qe6$m53$1@titan.btinternet.com...
> make sure you have service dhcp enabled as well.
>
> Jimmy
>
> "Steve Burton" <steveburton@nf.sympatico.ca> wrote in message
> news:Omnbc.8844$Np3.293253@ursa-nb00s0.nbnet.nb.ca...
where[color=blue]
>
>
| |
| Jimmy 2004-05-04, 11:26 pm |
| Try using an ip helper address with 'no service dhcp'. It doesnt work.
"Steve Burton" <steveburton@nf.sympatico.ca> wrote in message
news:7iDdc.14488$Np3.513541@ursa-nb00s0.nbnet.nb.ca...
> Not required.
>
>
>
> "Jimmy" <jimmy@the-dorans.com> wrote in message
> news:c54qe6$m53$1@titan.btinternet.com...
> where
>
>
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