Hi, All, I have a very basic and small scenario on VLAN and trunking technology that will be applied on our network. After searching on the Internet for a while I couldn't get clear specification anywhere to answer my questions. If you could help me out I will be really really appreciate it.
We have a network contains three distinct geographical locations that are connected each other by T1 lines (like a triangle). From one of the locations (Headquarter location) we use subscribed ADSL to connect to the Internet. The three sites each uses a Cisco 2610 router to do internal routing. The IP range is 192.168.x.x/24. The headquarter uses a Cisco 506E Pix to do NAT, VPN and access list control.
At present, we are upgrading bandwidth by replacing T1 with fiber optics. After the upgrade, the three sites will be linked to the ISP via fiber lines directly. The ISP will create VLANs for us instead of using subnets to segment the network. The configuration the ISP provided us is:
Public VLAN -101 (native VLAN) Private VLAN- 102
The ISP already created the two VLANs and VLAN trunking on their switch and asked us to follow up on our switch in the HQ site. Since the VLAN knowledge is absolutely new for me, I'd like to ask several pretty detailed questions over here and cordially hope you could help me out:1=2ESince VLAN101 is public VLAN, does it mean VLAN 102 is the only VLAN that our network devices should be put in? If it's the ONLY VLAN, since it contains more than 600 hosts, I will use a class B IP range, i=2Ee.,172.16.x.x/22 instead of 192.168.x.x/24. All devices within the same subnet don't need be routed to communicate each other. Is my understanding correct? 2=2ESince only one VLAN inside, inter-VLAN routing and router-on-a-stick have no use. Can we abandon routers and only use switches and PIX for traffic control? 3=2EWe are considering buying a new switch to be the core switch doing VLAN and trunking. The ISP engineer said it's really no matter the switch on our side a layer2 or a layer3. But if it's a layer 2 switch, how can we assign the IP address to the VLAN 102 port? Is a router which supports VLAN trunking still needed in this case? 4=2EOn the core switch, how many ports should be in the 802.1Q trunk? - Can I only set it up on the native VLAN101 port? How should I assign all the other ports on the switch then? Make them all ports for LAN102? Physically this switch's ports will connect network devices in the specific location and the fiber link box. (Sorry for my na=EFve question because I'm having difficulty to understand logical interfaces and physical interfaces in my performance of setting VLAN. I got difficult to find clear docs and examples on the Internet either.) 5=2EShould the PIX play any role in the VLAN configuration? Or I just leave its setting intact?
Thank you all for your assistance! Any post or link will be greatly appreciated.