C3750 & Stackwise

[s.hellman]

I'm have a 3750 with EMI. What will happen if I connect another 3750 with SMI through the Stackwise-port?

a) it wont work at all

b) the switches will continue running seperate images

c) the EMI will be copied to the new switch

[thisisshanky]

Check this link

http://www.cisco.com/en/US/products/hw/switches/ps5023/products_white_paper09186a00801b096a.shtml

Look for this section:

"Automatic Cisco IOS Software Upgrade/Downgrade from the Master Switch"

[pflunkert]

Hi,

i also like this site:

http://www.cisco.com/en/US/products/hw/switches/ps5023/products_configuration_guide_chapter09186a0080212739.html

On this site you will find the commands for configure stackwise.

Regards

Peter

[s.hellman]

Ok, so the EMI will be copied to the new SMI switch, but then you will violate the software policy.

[s.hellman]

Or maybe not, The whole stack will run EMI when the EMI-switch is master, but the SMI will still be installed on the SMI-switches. There will be no violation of the software-policy until I upgrade the EMI-switch, because then the new EMI will also be installed on the SMI-switches. Right?

[pflunkert]

Your statement is corect. But when your EMI switch reboots and your SMI will become the master. You loose the EMI funtions on your stack. And this is the problem. So you should have on both switches the same software.

Regards

Peter

[s.hellman]

Actually, it's only the EMI-switch that needs the EMI-features, the SMI-switch wont do any routing or other advanced tasks. It will work as long as the EMI-switch will be master again when it comes back up. And if i got it right, it will take the master role again.

[mcardell]

Hi all,

sorry to crash into your conversation, but I would like some feedback on convergency time for the WiseStack technology.

If one of the switches fails or the stackwise links fail what is the convergency time for the whole stack to be up and running? any loss of connectivity (or packets) for the users of the stack?

Thanks

Matteo

[pflunkert]

Hi Matteo,

the client don't see any interupt of the traffic. Only the affected switch will have problem (and the connected clients:

Here are one statement from Cisco (Q&A Cisco 3750, CCO Website):

"Cisco StackWise technology provides an innovative method for collectively using and extending the resources of a stack of switches. Up to nine switches can be joined together to create a single switching unit with a virtual 32-Gbps stack interconnection. Furthermore, the entire stack can be managed as one unit with a single IP address. To the rest of the network, the stack operates as a single switch. With a unified management interface, the customer can with one command load a single image to all compatible switches on the stack. Cisco StackWise technology is optimized for Gigabit Ethernet deployment, bringing customers new levels of performance through the high-speed interconnection, resiliency through advanced failover mechanisms, and ease of use through automated configuration and a single management interface.

Because of the Cisco StackWise technology, the Cisco Catalyst 3750 Series is highly scalable. There can be up to 252 Gigabit Ethernet ports in a stack. Switches within the stack can be added and removed without affecting network access. New devices take the global configuration from the stack master, and replacement devices take the exact configuration of the old device. There is one configuration file with all stack member configurations.

The innovative design of the Cisco Catalyst 3750 Series sets the bar of availability in stackable switches. It supports link- and switch-level redundancy. The Cisco Catalyst 3750 Series supports cross-stack Cisco EtherChannel® technology as well as Cross-Stack UplinkFast (with subsecond failover), and cross-stack equal-cost routes across different switches in the stack. These features eliminate dependency on Hot Standby Router Protocol (HSRP) for router failures. In the case of a master switch failure, another master switch takes over with minimal disruption within 2 to 3 seconds.

For more information about Cisco StackWise technology, go to:

http://www.cisco.com/go/catalyst3750.

"

Regards

Peter

[pflunkert]

Hi, your statement is corect but recommended. Whem your EMI switch is wrong, you will loose all EMI capabilities in your stack.

Regards

Peter