What is the max bandwidth of a L3 VLAN interface?

[ahmadali7]

 Dears,

    I have core switch 6509-E (WS-SUP720) ,and receiving  a high utilization on interface Vlan. The current bandwith is 1GB, and I want to increase it. is there is any way to increase the bandwidth for the interface Vlan??!

Regards,

Ahmad Ali

[Martin Carr]

That is the interface bandwidth?

Ideally you need to determine the source of the traffic. If it's from an edge switch for example,then it's an idea to create an Etherchannel, which is good practice anyway.

Martin

[ahmadali7]

Hello Martin,

No bro this is interface Vlan(L3) bandwidth not interface from edge switch. Also, Iam using this interface Vlan for the servers.

Regards,

Ahmad Mestarihi

[Richard Burts]

It is not clear to me whether your question is about changing the configured bandwidth of the vlan interface or whether it is about the capacity of the vlan interface to forward traffic.

Since changing the configured bandwidth is a relatively trivial thing to accomplish I would assume that you are asking about the capacity to forward traffic. The vlan interface is a virtual interface and as such its capacity to forward traffic is based on the capacity of the physical interfaces that are in the vlan.

HTH

Rick

[ahmadali7]

Dear Rick,

   Thank you for your reply. Actually my question is to increase the capacity of the interface Vlan ( virtual interface) to receive and forward traffic .

  This interface Vlan we are using for a lot of servers , and the capacity of it 1GB  and always receiving alerts from solarwinds that we have high utilization on this interface vlan8.

Please find the attachments pictures from the solarwinds.

Regards,

Ahmad Mestarihi

[Richard Burts · Accepted solution]

Ahmad

Thank you. The additional information was helpful. The Solarwinds report was written for monitoring physical interfaces and it works well for physical interfaces. If the report says that the interface transmitted 32% or 64% or some other % then you knew with some accuracy how close you were to maximum utilization of the interface. But when it is monitoring a virtual interface like vlan 8 it does not really mean the same thing.

Let me try to explain it in this way - if Solarwinds says that vlan 8 is using 64% of 1 Gig, then it is saying that 64% of 1 Gig was the aggregate utilization going out all of the physical interfaces in vlan 8. If there are, perhaps, 8 physical interfaces in vlan 8 then realistically each physical interface is at about 8% utilization and the 64% reported on the virtual interface is really not alarming. You might try using the bandwidth command in interface config mode for vlan 8 and set some value higher than 1 Gig and see if that helps with the reporting.

HTH

Rick

[ahmadali7]

Dear Burts,

This is great explanation. As you said , I will try to use bandwidth command in the interface vlan to increase the capacity and see.

Thank you so much for this and I really appreciate it.

Regards,

Ahmad Mestarihi

[Richard Burts]

Ahmad

You are welcome. I am glad that my explanation was helpful. Thank you for using the rating system to mark this question as answered. This will help other readers of the forum to identify discussions that have helpful information. This forum is an excellent place to learn about Cisco networking and I hope to see you continue to be active in the forum.

HTH

Rick

[ahmadali7]

yes bro your explanation was great,.

Sure I will be active and I strongly like this forum.

Regards,

Ahmad Mestarihi