"Virtual" Networking

[SimonMac]

I have created a SysTest environment at ClientCo, each with two NIC's one for a management LAN and one I want to create a mini back LAN with Windows NLB etc. For the management LAN I know I have to use "real" IP's in use by the company, to save IP addresses can I use real IP's for the NLB but mock IP's for the NIC's connected to the BackLan as it will only ever be used between the servers?

Like this:

Real IPs 10.x.x.x

Server 1
Main Lan 10.0.0.1
Back Lan 192.168.1.1

Server 2
Main Lan 10.0.0.2
Back Lan 192.168.1.2

BackLan NLB 10.0.0.3

Hopefully this will mean the BackLan NLB will be accessible from the corporate LAN? Currently the BackLan is using the same IP range as the Main NIC but I want to give back some of the IP's I have allocated on the subnet.

Does this make sense?

 

[stek]

Both those ranges are private IP's, not 'real' ones. Aside from that if I've understood properly you'll need to set up static routes on the servers to route between the two networks.

I'm not a Network guy tho!

 

[SimonMac]

Both those ranges are private IP's, not 'real' ones. Aside from that if I've understood properly you'll need to set up static routes on the servers to route between the two networks.

I'm not a Network guy tho!

Neither am I

I know both ranges are private, but I mean a real IP as in the sense of one in use by the company which anyone internally can hit, compared to set of addresses that I have just made up for two servers to use if both are configured correctly.

I am starting to think this may work as long as there is a gateway configured for them both to use within the VM solution

 

[garethevans1986]

Say you create 3 virtual machines, connect them to a virtual switch (vswitch with ESXi), give them an IP of the local network (with a 10.0.0.0/8 network you've got 65k IP addresses.)....they will communicate using the vswitch rather than going to a physical switch - no need for the secondary network connections.

GE

 

[SimonMac]

Say you create 3 virtual machines, connect them to a virtual switch (vswitch with ESXi), give them an IP of the local network (with a 10.0.0.0/8 network you've got 65k IP addresses.)....they will communicate using the vswitch rather than going to a physical switch - no need for the secondary network connections.

GE

Thats kinda what I was getting at, as long as they are configured right I can just set up as many virtual subnets I like without affecting the rest of the network

 

[garethevans1986]

You will only cause yourself a headache if you give each virtual box a 10.0.0.0 and 192.168.0.0 address.

GE

 

[Incognito]

Say you create 3 virtual machines, connect them to a virtual switch (vswitch with ESXi), give them an IP of the local network (with a 10.0.0.0/8 network you've got 65k IP addresses.)....they will communicate using the vswitch rather than going to a physical switch - no need for the secondary network connections.

GE

Jeyzuzz H Christ. Simon, do NOT ******* give your VM's IP addresses from your production network if you do not want them to be routable.

Gareth, read up on what broadcast domains and ARP are.

Hopefully this will mean the BackLan NLB will be accessible from the corporate LAN? Currently the BackLan is using the same IP range as the Main NIC but I want to give back some of the IP's I have allocated on the subnet.

Does this make sense?

Depending on your O/S it is easy or it is 'less' easy. Server 2008 introduced the concept of the Strong Host Model. If using 2K8 then you'll need to do a bit more engineering around static routes on your NLB VMs to get them to talk over the 192 NICs. I could sit here for half an hour typing out or point you to a good blog article.

Enjoy.