3com 4250t 2 vlans, one server to be seen from both, dont work. 1

[linaz]

Hi all,
I have situation in which i need help.
I have customer which want to divide his lan to two vlans.

The vlan_trainees and vlan_office. Company has two 3com switches - 4250T(3C17302).

Office vlan has 17 PCs
Trainee’s vlan has all others which are - 78 PCs
And one server which is a gateway to internet.

office vlan:
9 pcs are connected to switch no1, and 8 pcs are connected to switch no2.

trainees vlan:
all others interfaces on the switches belong to vlan trainees.

Did you still follow me? I hope you do.

I connected switch No1 to switch No2 using ports 49/up (switch No1) to 50/down (switch no2).

As this is a stacking theory, is it ?

I gave ip address:

Switch No1 - 192.168.1.8
Switch No2 - 192.168.1.9

I installed software 3Com Switch Manager, to the server and i created one new vlan. Because by default there is one already. So, vlan1 is the one for trainees. And the vlan2 which i created is for office. Now I have two vlans. Then I select “layer 2 vlan management” and when move ports from vlan1 to vlan2. Switch No1 has 9 pcs which belongs to vlan2, they are connected accordingly from port 1-9. Switch No2 has 8 pcs which belongs to vlan2 and they are connected accordingly from 1-8. So I select them ports and give them id of vlan2. So I have lan which has two vlans.
I have server which has to be seen by both vlans. Server is connected to port 18 on switch No1.
In 3Com Switch Manager program window I select the port No 18 on switch No1, and right click on it, I select “add to vlan” and I add to vlan2. So this port has vlan 1 and 2. So I think that both vlans should see this port.
Now, I am near one of the office pcs, and this pc is not picking the IP address(this pc is in vlan2). The ip addresses are given by server which is conneted to port No18. No I go to the trainees pc(vlan1) they have an ip address and I can ping server. So it looks like the vlan1 has access to port 18(server) but vlan2 cant access port 18(server).
Questions would be:
Am I doing something wrong?
Could someone give me a detailed correct path to do this?
If no I have questions:
The two switches do they have to have separate IP address?

Then I stack the switches, I connected switch No1 to switch No2 using ports 49/up (switch No1) to 50/down (switch no2). How should I add them two ports to both vlans? Because to communicate between two switches these two ports has to be seen in both vlans Is it? If i stack switches, the ports 49 on both switches becomes green, and i cant select port 50 to add it to both vlans, because both 50 ports are grey(not accesible).

How should I add port18 to both vlans, what is the correct way of doing this?
Is this possible at all to have server (port18) been seen from both of vlans, in the same time the vlans can’t see each other?

I spent 12hourse loking to this already, i cant get any useful information from documentation.

So i appreciate your help !

Thanks
Junior Engineer.
Linas

 

[IRudebwoy]

VLANs are logical segments. For ease of management use different IP ranges for each segment. This requires you to use a router, either the switch or an external router which allows both segments to see each other (with the proper routing table on your devices). The external router is probably what you need because your switches lack Layer 3 features (IP routing).

The IP addresses for the switch dont't have to change but you need to do some more research.

If your server has two NICs you can put your server on each VLAN and assign an appropriate IP address. This method doesn't require a router but each VLAN will not be able to communicate with each other, unless you can configure your server as a router (not recommended). Otherwise more research is required on your part (802.1q VLAN tagging).

Have Fun!

 

[linaz]

Hi IRudebwoy,

Yes it seems like i wont be able to set up an Vlans without a router.

Another your suggestion have intrested me, there are already two cards on server, because we have ISA server running. But there are no restirictions to install third one.
I have a try.

I have one more question for you:
"If your server has two NICs you can put your server on each VLAN and assign an appropriate IP address."

You mean to put different scopes? Or leave one scope and just assign ip.

Thanks for help.

I heard that 3com has a way of doing this without a router, if anyone has an idea please let me know.

Rgrd's
Linas

 

[IRudebwoy]

You can assign an IP to each NIC that is appropriate for the VLAN you need to connect. On the switch make the connecting ports an untagged member of the appropriate VLAN.

If your VLANs have different IP scopes (like 192.168.2.0/24 and 192.168.3.0/24) your server can communicate on both network segments. Your clients on one VLAN cannot communicate with clients on the other VLAN.

Buy a switch with layer 3 features (routing) and connect your servers to it. You can the create another IP interface to route between your segments (clients on either VLAN can communicate with each other).

Have Fun!