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VLANs networks receiving IPs from DHCP by a Windows Server running on ESXI 5.5

edu87
edu87 asked
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I would like to know the best practice to distribuite IPs by windows server DHCP for a multiple VLAN environment using Vmware ESXI 5.5?

The switch interface that is connected to the ESXI server is in trunk mode.

I made a home lab to test this and worked, but I don´t think that this is the "correct" way. This is what I did:

Environment:
- Lan with vlan 10 (192.168.10.0)
- Lan with vlan 20 (192.168.20.0)
- Lan with vlan 30 (192.168.30.0)

With a virtualized windows server in ESXi I installed 3 network cards in windows, and installed DHCP server with 3 scopes.
- nic 1 = 192.168.10.1 (assigned with VM NETWORK VLAN 10)
- nic 2 = 192.168.20.1 (assigned with VM NETWORK VLAN 20)
- nic 3 = 192.168.30.1 (assigned with VM NETWORK VLAN 30)

Thanks!
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AkinsdNetwork Administrator

Commented:
If you meant standard practice, then yes

In other to pass multiple vlans through a switched connection, the switchport must be in trunk mode.

Also noteworthy is the fact that configuration decisions are based on preference.
That's why it is important to have a goal, then meet it.

As such, there is no correct or incorrect way if the design is working.
This will work for a lab, but ideally you would use an IP Helper on your router to forward the DHCP requests to your DHCP router. on a cisco for example, ip helper-address x.x.x.x

What this does is encapsulates the broadcast to it can be sent over an ip network, the DHCP server, assuming sites and services has the subnets assigned, sees the source interface of the router and returns an IP on that network.

Author

Commented:
I did the setup on my Cisco SG300 by enabling the DHCP Server Relay and pointing to my Windows Server DHCP  and worked perfectly.

I dont´t know if is just the switch SG300 Cisco, but I did not need to enable IP HELPER feature. Just made the settings of DHCP Server Relay following this tutorial and now is working ok:

http://sbkb.cisco.com/CiscoSB/GetArticle.aspx?docid=d8d34abcd43d445f95073301cae9fbd2_DHCP_Relay_Configuration_on_Cisco_300_Managed_Switch.xml&pid=2&converted=0
AkinsdNetwork Administrator

Commented:
IP-Helper Address (Cisco command) = DHCP relay

I would like to know the best practice to distribuite IPs by windows server DHCP for a multiple VLAN environment using Vmware ESXI 5.5?
= Trunking
That works too, I think you would have to use the ip helper-address if your were crossing a router edge

Author

Commented:
Akinsd,

I think SG300 is a little bit different:

cisco.PNG
But there is one option for Ip Helper, and I didn´t understand why I don´t needed to set it:

cisco1.PNG
the commands are similar but not the same.  DHCP relay handles DHCP, ip helper handles broadcast, which DHCP is, so you could send other broadcast traffic across as well like, dns, tftp and netbios.

Author

Commented:
I tryed to set the IP helper with port 67, and a message says that DHCP is already reserved. So I assume that in this case I must use the DHCP Relay.