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699
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11
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How many VLANs for a branch office

thomuff
Level 3
Level 3

I am getting ready to write a proposal for a WAN/LAN upgrade for a Financial institutioin. For the branch offices, they are saying they want the following vlans

VLAN 2 - Data

VLAN 3 - Voice

VLAN 4 - ATM

VLAN 5 - Printers

VLAN 6 - VPN failover

Is this overkill or right on target. Please give me your thoughts.

Thanks in advance.

8 Replies 8

Prashanth Krishnappa
Cisco Employee
Cisco Employee

Its good that you are reducing broadcast domain by segmenting into VLANs. 5 VLANs is not a big number and you should be fine. One thing is make sure you configure inter VLAN routing on a switch which can route/switch packets in hardware(such as 3550/3750/4500/6500).

that is another battle, instead of using inter vlan routing, they want to use static routes between the router and the switch. The reason being is the cost difference between the SMI and EMI.

If you are using an external router(router on a stick) for routing between VLANs, you might run into a bottle neck between the switch and router. BTW, a switch with SMI image can route between VLANs.

how? besides rip

To route between VLANs, all you need to configure on a switch is interface VLANs for every VLAN and assign IP addresses to it. This IP address would be the default gateway for devices in the VLANs.

For reaching a router connected to the switch, you could use RIP or static routes. This way all interVLAN traffic is routed on the switch and not the router.

Thats funny! We said the same thing at the same time. Thank you for that explanation. It wasn't clicking.

LATINMUSIC75
Level 1
Level 1

thomuff,

How are you going to distributed the IP address to the 5 VLANS.

Thanks

they plan having a vlan interface for each vlan, then you have a static route pointing all traffic to the router. On the router, you have static routes for 4 of subnetworks pointing back to the switch.

Believe me, I would like to do inter vlan routing.

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