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New Member

2924 and 5505 Vlan questions

1. I have a 2924 that I have segmented into 3 Vlans all on seperate subnetworks, I have a 100Mb connection to my central router for each Vlan. The question I have is do I have to have the 3 100Mb connections or is there a way to have all 3 Vlans traffic routed over one 100Mb trunk.

2. I also have a 5505 that I would like to use in the same manner. I currently have three 100Mb connections from a router feeding 3 differant switches a 5505 and two 2924's each on seperate subnetworks. Is there a way to have one 100Mb connection feed the 5505 and establish Vlans off the 5505 for the two 2924's without using a route switch module even though they are on seperate subnets?

New Member

Re: 2924 and 5505 Vlan questions


In reply to your queries:

1. Yes, you can most definately have all 3 VLAN's traffic routed over one 100MB link from router to switch. This uses a concept called VLAN trunks which is quite common in switched networks today. You need to see what kind of router you have got. If it is Cisco the chances are it does support VLAN trunks. You need to set-up both the uplink port on the switch and the ethernet port on the router to the type of VLAN trunk you require. You are best looking on the Cisco website to see how to configure this.

2. Yes, this could be done but it would be tricky. You would need to use VLAN trunks from the 2924 to 5505, then another trunk to the router from the 5505. Again, you would need to look at the website for the config commands or I would be typing forever!

Hope this helps,


New Member

Re: 2924 and 5505 Vlan questions

Ok.You can configure the interface of 2924 used to connect Router to trunk mode,then on the router you can create subinterface to routing traffic from different vlan.The router(1600/2600/3600) must have IP PLUS or more high version to support subinterface 7000 or high can support subinterface with any version IOS.

for question 2,you must config interfaces between network device to trunk mode.

on 2924:

int fast 0/20

switchport mode trunk

switchport trunk encap isl/dot1q

On 5505:

set trunk x/y on isl

on Router

int fast 0/0.1

encap isl/dot1q VLAN#1

ip address x.x.x.x

int fast 0/0.2

encap isl/dot1q VLAN#2

New Member

Re: 2924 and 5505 Vlan questions

You can connect your router to the first switch via a trunk port. You configure one port on your router and one port on your switch as a trunk port with a 100mb connection between them. The trunk port will carry the communications from multiple vlans. You can then connected switch two and three to switch one via 100mb cross over cables.

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