data center Design

[Network Pro]

hi,

if  you need to design a large campus area network with two 6500 and edge  switches and distribution switches what will be the best design

1. is it better to etherchannel two 6500 at the core OR is it better to run routing protocol between both the cores

2. is it better to etherchannel core switches to distrubution or run routing protocol between them ?

3. is it better to etherchannel distrubution switches to access switches or run routing protocol between them?

basically i want to know where to run routing protocol between in the cisco 3 layer architecture ?

thanks

[Leo Laohoo]

Duplicate post.

[Network Pro]

yes i thought i posted in the wrong place...i thought you would provide me an asnwere instead of just sayng duplicate post !!!!!

[Leo Laohoo]

i thought you would provide me an asnwere instead of just sayng duplicate post !!!!!

Delete one of the two (duplicate threads) and I'll post something technical to your issue.

PS:  It's night time now.  So I'll post when I wake up tomorrow.

[Network Pro]

sorry how do i delete a thread..never had to do this before..

[Leo Laohoo]

Go to the other thread you've posted.  Upper right-hand corner under the Actions window there's an option to DELETE.

[Network Pro]

can only see these options

• Edit discussion
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[Leo Laohoo]

I've requested the OTHER thread be deleted. 

[Leo Laohoo]

1. is it better to etherchannel two 6500 at the core OR is it better to run routing protocol between both the cores
2. is it better to etherchannel core switches to distrubution or run routing protocol between them ?

BOTH.  You can run either a Layer 2 or Layer 3 etherchannel.  So it doesn't matter.  But deploying an etherchannel (1 Gbps, 10 Gbps, 40 Gbps, 100 Gbps) is a no-brainer.

Whether or not you want to run Layer 2 or Layer 3 etherchannel, in my opinion, depends on the desig and the size of your network.  If you have a clean sheet of paper then I'd think 20 years in the future.  I'll enable Layer 3 (IPv6 if possible) to all my switches.  Layer 3 etherchannel and fibre optic to the uplink.

[Network Pro]

so on the core you say to run layer 2 or layer 3 etherchannel - ok say if i am gong with layer 3 etherchannel then do i run any routing protocol between them ?

2. considering its a big network - then  i run routing between core and distribution switches ?

3. and do i run layer 2 between distribution and access layer ?

[Leo Laohoo]

3. and do i run layer 2 between distribution and access layer ?

If I was designing a network, I'd run Layer 3 etherchannel, PERIOD.

The main point-of-contention is the COST.  If I was to deploy a Layer 3 all the way down to the access layer then I need to have a switch that will support routing.

Whether or not you should run Layer 2 or Layer 3 is all up to you and how to push a business case about this.

[Network Pro]

what is cisco best practise?

[siddhartham]

According to Ciso best practices VLAN localization is the best option, this will lead to 2 designs

1.Routed distribution layer

2. routing upto access layer.

Option 2 is costlier than option 1 and buliding a routed 3750 stack is an example of option 2.

"------1. is it better to etherchannel two 6500 at the core OR is it better to run routing protocol between both the cores"

If you configure any VLANs on the core (Collapsed core distribution model)  then you would need layer 2 ether channell for HSRP but its not a best practice.So a layer 3 ether channel with routing protocol ( either EIGRP or OSPF)

"-------2. is it better to etherchannel core switches to distrubution or run routing protocol between them ?"

Cisco recommends to create a layer 3 distribution block for each IDF (or for building based on your design) and a layer 3 distribution block for the Data Center (based on the size of your datacenter you can add its own core switches)

So a layer 3 ether channel with routing protocol( EIGRP or OSPF ) between core and distribution switches.

"-------3. is it better to etherchannel distrubution switches to access switches or run routing protocol between them?"

If you go with option1-routed distribution and layer 2 access layer then you will need a layer 3 ether ether channel (EIGRP or OSPF) betwwen 2 distribution switches for routing redundancy and layer 2 ether channel for HSRP and layer 2 redundancy.You can connect each access layer switch with both the distribution switches and STP to avoid loops.

If you go with option 2 -Routed access layer then there won't be any STP and you will run routed links between distribution and access layer. You can uses a pair of 4506 switches or 3750 stack switches for this whole stack acts as a Distribution/access layer.

[danrya]

I would recommend that you keep it simple.  If your going to run L3, then I wouldn't recommend L3 etherchannels.  Routing protocols are pretty fast at detecting failures, and if you concerned with increasing the speed, use BFD on the direct links.  Equal Cost Multipath (ECMP) is capable of using multiple equal cost L3 links for traffic distribution.

So, here's what I would recommend:

1.  Do you need VLAN's to be accessible on multiple access switches?

If no, then use multiple L3 links to the access and use OSPF/ISIS (and possibly BFD) to ECMP over all of the links.  By using individual L3 links, you can also connect to multiple distribution switches.

If yes, then use L2 port-channel or vPC (multi-chassis port-channel) from distribution to access.

2.  Always use individual L3 links in the Core and the distribution if possible.

Again, if you have multiple links, and you add port-channels, and then add routing protocols, it get's more complicated, and more things can break.  Let the routing protocols do there job.

Dan

[Network Pro]

so this is what my understanding is from the posts above. please correct me if i am wrong

considering the cost is not an issue and business is willing to invest in what ever devices we want .

i will go by the cisco 3 layer architecture:

1. use two 6500 as core and run routing protcol (either ospf or eigrp)

2. a. use two 3750 as distrubution / aggregation as run routing protocol between 6500 and 3750 (dual connecting to each 3750 from each core)

    b. run a port channel between two cisco 3750 (layer 2)

3. use cisco 2960 as layer 2 between distribtuion and access (hsrp on 3750 to access layer)?

will this work ?

also where will i terminate the firewalls ? or the core or on distrubution ?

Thanks