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New Member

PVLAN STP or Etherchannel, what's better?

Linking 2 6500's with 10GB uplinks, what is best practice/better? per Vlan STP or etherchanneling the 2 10GB links? Thanks to all.

1 ACCEPTED SOLUTION

Accepted Solutions

Re: PVLAN STP or Etherchannel, what's better?

Hi Saurabh,

I dont agree with your comments on PVST. We can use PVST for layer-2 load balancing as well. PVST is by default enable on the Cisco switches.

I Would suggest to have a 10GB etherchannel between the chassis. This will give a you logical load-balancing link and an aggregate throughput so it will be 40 GBPS full duplex.

PVST will not provide the load-balancing in this case if you are uplinking both the 10GB links directly to another 6500. PVST will be helpful in the scenario when you are uplinking a ditribution switch with 10GB links going to 2 different Core-switches. This way you have few vlans traffic to go on one link and the rest of the vlans traffic to take another link.

So my suggestion to use a ether-channel between the 2 chassis.

HTH,Please rate if it does.

-amit singh

6 REPLIES

Re: PVLAN STP or Etherchannel, what's better?

PVST and etherchannel serve different purpose.

they are not same. PVST is used to eliminate layer 2 loops in redundant topology. While etherchannel is used for load balancing.

It depends on what exactly you want, you can go for that particular feature or for implementing both.

hope to help ... rate if it does ...

Re: PVLAN STP or Etherchannel, what's better?

Hi Saurabh,

I dont agree with your comments on PVST. We can use PVST for layer-2 load balancing as well. PVST is by default enable on the Cisco switches.

I Would suggest to have a 10GB etherchannel between the chassis. This will give a you logical load-balancing link and an aggregate throughput so it will be 40 GBPS full duplex.

PVST will not provide the load-balancing in this case if you are uplinking both the 10GB links directly to another 6500. PVST will be helpful in the scenario when you are uplinking a ditribution switch with 10GB links going to 2 different Core-switches. This way you have few vlans traffic to go on one link and the rest of the vlans traffic to take another link.

So my suggestion to use a ether-channel between the 2 chassis.

HTH,Please rate if it does.

-amit singh

New Member

Re: PVLAN STP or Etherchannel, what's better?

Hi Amit,

Thanks for your answer, it makes perfect sense, would it also make sense to configure PVLAN STP on the access switch that has an uplink to each 6500 core switch if I'm running Core 6500A as root for Odd number Vlans and Core 6500B as root for even number Vlans? is that a good way to do it? This may be what you already mentioned with a distribution switch, thanks again!

Re: PVLAN STP or Etherchannel, what's better?

Hi,

Yes, this makes sense and infact this is one of the best practices that we use when designing the load-sharing redundant network. Yes I would strongly recommend you the same design i.e having 6500A as primary root bridge for ODD vlans and secondry root for EVEN vlans and vice-versa on 6500B.Please also have HSRP configured the same way for layer-3 as well. have 6500A MSFC as the primary router for ODD layer3 vlans and standby for EVEN vlans and vice-versa on 6500B.

Let me know if you have more questions on this.

HTH,Please rate if it does.

-amit singh

New Member

Re: PVLAN STP or Etherchannel, what's better?

Amit, same idea can be applied for server farm switches and so on, correct?

Re: PVLAN STP or Etherchannel, what's better?

Yes, the same idea extends to server farm switches also. I generally prefer having layer-3 links from the server-farm switches or dirtibution switches to core switches. This way we can contain the local layer-2 traffic like STP,broadcast etc. to those switches only and do not extend the STP/broadcast domain to core so that core switch doesnot have to process unncessary traffic.

HTH,Please rate all the posts that helped.

-amit singh

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