Help..Vlans..

sarfarazkazi · ‎05-15-2008

Hi,

Currently we are having a flat network for our office. There is a existing manageable linksys switch with vlan support. There is a cisco 877 ADSL installed for internet access.My question is as per the design that I am planning:-

1. The uplink from the adsl to the switch will be in which vlan?

2. I want to put my domain and isa server in one vlan.

3. The purchase and the accounts dept in separate vlans.

4. There are some wireless APs installed, they should be in a different vlan.

If I put them in separate vlans will they be able to access internet and email? Kindly give me your valuable inputs.

andrew.prince · ‎05-15-2008

Sarfaraz,

If you have multiple VLAN's and you want them to inter-communicate, you need a layer 3 device i.e a router.

The router will effectivly be in ALL VLAN'S as the router will have to be able to route the packets. To asnwer your questions:-

1. The uplink from the adsl to the switch will be in which vlan? All VLAN's.

2. I want to put my domain and isa server in one vlan. OK - does the linksys switch support Dot1Q trunks?

3. The purchase and the accounts dept in separate vlans. Again - does the linksys switch support Dot1Q trunks

4. There are some wireless APs installed, they should be in a different vlan. Same as 2 & 3

f I put them in separate vlans will they be able to access internet and email? Kindly give me your valuable inputs. Yes - the routers interface will be configured to support Dot1Q Trunking, and each VLAN will have a layer 3 interface in the router.

A possible VLAN Structure could be:-

VLAN # - Data, general machine IP connectivity, including router and firewall.

VLAN # - Server VLAN, Domain & ISA server.

VLAN # - Purchasing VLAN, All purchasing machines

VLAN # - Wireless VLAN, all wireless AP's

It all denpends on the switches! And of course the 8xx range are limited to 4 802.1q VLAN's - which is lucky as that is the number you are looking at!

HTH.

keeleym · ‎05-15-2008

Hi There

Just to add to Andrew's last statement, The 877 range of routers will support 4 VLANS but I think that you have to have the Advanced Enterprise IOS.

I have an 877w at home as my internet router and it has Advanced IP Services IOS. This only supports 2 VLANS and I get an error if I try to create another SVI.

Best Regards,

Michael

sarfarazkazi · ‎05-16-2008

1. The uplink from the adsl to the switch will be in which vlan? All VLAN's.

* What exactly do you mean by the router will be in all vlans? I am a litte confused with this reply. Do I have to configure a trunk between the linksys switch and the router? Yes the linksys supports dot1q trunks.

2. If I put them in separate vlans will they be able to access internet and email? Kindly give me your valuable inputs. Yes - the routers interface will be configured to support Dot1Q Trunking, and each VLAN will have a layer 3 interface in the router.

* If I dont dont use a layer 3 interface the domain and the ISA server will be inaccessible?

andrew.prince · ‎05-16-2008

1. Yes

2. Yes