need help on C3750 stacking

[srikanth ath]

Hi all

Stuck with Stacking.

I have two switches(3750 (a) & (b)), I wanna stack these switches. As one switch will be back up of another.

• •1.      On switch (a) I have created vlans and assigned ports to it (20 servers are connected to switch (a) ). Does the switch (b) learns the same vlans and the port assigned to it and when the switch (a) is down , if YES,  how the connected traffic of servers in switch (a) is moved to another switch as the switch is completely down.

Or

            Should I have to manually assign vlans to switch(b) and move the connected servers to switch (b)    if switch (a) fails.

• •2.       switch (a) is connected with 2960 switch where 40 users connected to it and created 4 vlans. As switches are stacked , in switch (a) (which is intervlan routered and static route provided to go to firewall) if this is down does the traffic go out of the switch (b) where firewall is connected.     Or should I have to manually configure the same thing in switch (b) like intervlan routing and static route to firewall.

Really facing a big problem to understand the concept of stacking.spent hell out of the time on this.

Thanks & regards

srikanth

[Latchum Naidu]

Hi Srikanth,

Not sure if I understand correctly...
If you have 2 switches in a STACK that means they will act and work as a single switch. But you need to have a redundant physical connection from your Server/router/firewall to both switches so that if one switch in STACK is down the other switch in STACK can handle the traffic.

The below is how STACK behaviour...

STACK cable works only when both switches that its connected to is still up and running.

If you have two switch in a STACK for the purpose of redundancy, make sure that the uplink (router or firewall) is connected to both switches.

If your server NIC1 and NIC2 is configured as NIC-Teaming and the ports where its connected to in BLADE1 and BLADE2 switches are in the same VLAN, then if one of the switch fails, the server connection to the network failsover to the other switch.

If you configure interVLAN routing in a STACK switch, when the MASTER switch fails, though one of the member switch will be elected as MASTER switch, all VLAN interface MAC addresses change.

Please rate the helpful posts.
Regards,
Naidu.

[srikanth ath]

hi

i got this the only thing im looking is how the configuration are exchanged between these two switches.the two cases where im stuck is .above mentioned two cases how the stack behaves ... . i will make sure to uplink the two switches and for redundant will connect these twwo switches to firewall.

1.Should I have to manually assign vlans to switch(b) and move the connected servers to switch (b)    if switch (a) fails.

2.

Or should I have to manually configure the same thing in switch (b) like intervlan routing and static route to firewall.

[Latchum Naidu]

Hi Srikanth,

Whe you do STACK it means it is a single management interface for all rest of the network.
If you have vlans configured in switch A then connect switch B as a member so that the new device get the global configuration from the stack master

Please rate the helpful posts.
Regards,
Naidu.

[srikanth ath]

ohk let me u guys clear

two switches connected to firewall directly.    switcha ---- firewall-----swtichb

the only concern i have is if the two switches are stacked . how the configuration is exchanged from master switch to slave switch and what are it effects in the following two cases.

•     On switch (a) I have created vlans and assigned ports to it (20 servers(leave the part of NIC teaming) are connected to switch (a) ). Does the switch (b) learns the same vlans and the port assigned to it and when the switch (a) is down , if YES,  how the connected traffic of servers in switch (a) is moved to another switch as the switch a is completely down.

Or

            Should I have to manually assign vlans as same as switch(A) in switch(b) and move the connected servers to switch (b)    if switch (a) fails or i shouldnt move the servers connected to ports of switch (a)

• how the switch(b) stacked learns the vlans of 2960.   

switch (a) is connected with 2960 switch where 40 users connected to it and created 4 vlans. As switches are stacked , in switch (a)  if this is down does the traffic go out of the switch (b) where firewall is connected.     Or should I have to manually configure the same thing in switch (b) like intervlan routing and static route to firewall.

thanks and regards

srikanth

[Zeeshan Siddiqui]

Hi Srikanth,

With a Stack You have one managment address stacking it up will make it a big switch.

It is like you are adding extra ports to a switch you can also manually configure the Master switch by increasing the priority.

The link below explain how to setup 3750

http://www.cisco.com/en/US/products/hw/switches/ps5023/products_configuration_example09186a00807811ad.shtml#Add

Kind Regards,

Zeeshan Siddiqui

[Joseph W. Doherty]

Disclaimer

The     Author of this posting offers the information contained within this     posting without consideration and with the reader's understanding  that    there's no implied or expressed suitability or fitness for any   purpose.   Information provided is for informational purposes only and   should not   be construed as rendering professional advice of any kind.   Usage of  this  posting's information is solely at reader's own risk.

Liability Disclaimer

In     no event shall Author be liable for any damages whatsoever   (including,   without limitation, damages for loss of use, data or   profit) arising  out  of the use or inability to use the posting's   information even if  Author  has been advised of the possibility of  such  damage.

Posting

When you stack 3750, the stack becomes one logical device.  I.e. no more switch A and switch B, just one combined switch X.  Configuration is much like a chassis where the individual member switches are configured similar to chassis line cards.  (NB: when you combine individual switches into a switch, don't believe prior configs will auto merge.)

For your questions about what to connected to what, think how you would wire up a chassis with the same number of line cards.