cargex
asked on
How to add a Cisco 3850 to a Cisco 3750 Stack
Hi Guys,
I have a 3750 Stack and my understanding is that the 3750 will go end of life this August, and the new 3850 will replace it.
I need to purchase a new 48 port switch but my understanding is that the 3850 won't stack with the 3750.
Being that the case I do want to start a new 3850 Stack instead of buying an old 3750.
My question:
What is the best way to connect one brand new 3850 to a 3750 Stack?
An old school cross over Ethernet cable using regular ports?
Purchase an additional network module for both Switches?
Thanking you in advance,
Cargex
I have a 3750 Stack and my understanding is that the 3750 will go end of life this August, and the new 3850 will replace it.
I need to purchase a new 48 port switch but my understanding is that the 3850 won't stack with the 3750.
Being that the case I do want to start a new 3850 Stack instead of buying an old 3750.
My question:
What is the best way to connect one brand new 3850 to a 3750 Stack?
An old school cross over Ethernet cable using regular ports?
Purchase an additional network module for both Switches?
Thanking you in advance,
Cargex
SOLUTION
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ASKER
Hi Guys,
Do I need to install additional hardware to the 3750 for that Etherchannel?
Do I need to install additional hardware to the 3750 for that Etherchannel?
Nope. Just connect however many cables you need and then configure the etherchannel on each switch.
ASKER
I'm going to use 2 ports in each switch to configure the EtherChannel
Question:
Will all my VLAN information just propagate through the EtherChannel?
Or do I need to add some trunk configuration to the ports involved in the EtherChannel?
Question:
Will all my VLAN information just propagate through the EtherChannel?
Or do I need to add some trunk configuration to the ports involved in the EtherChannel?
SOLUTION
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ASKER
Is this the best practice to interconnect 2 Stacks?
Because now I'm thinking that Cisco Switch Stacks do have a limit and once you reach the limit you will need to start a brand new Cisco Switch Stack, so my question is:
Is this the best practice to interconnect 2 Stacks?
Because now I'm thinking that Cisco Switch Stacks do have a limit and once you reach the limit you will need to start a brand new Cisco Switch Stack, so my question is:
Is this the best practice to interconnect 2 Stacks?
Without looking at documentation, I think max switches per stack is either 4 or 5. How you interconnect them depends on your design really. You can do either etherchannel or routed links.
It won't let edit on my phone. If you max out switches I the stack, I would probably look into dedicated core switches.
ASKER CERTIFIED SOLUTION
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Hi There,
I am a bit lost in understanding the question.
Are you trying to trunk the 3850 to the additional via etherchannels 3750 stack or are you planning to add 3850 to the existing 3750 stack?
The latter part is not possible since 3850's and 3750's have different stacking modules and cables.
In both the cases, since the 3750's are due for EOL, I ain't sure if the task you are attempting would suffice your requirement.
My suggestion would be to plan on seamless hardware upgrade of all your 3750's.
I am a bit lost in understanding the question.
Are you trying to trunk the 3850 to the additional via etherchannels 3750 stack or are you planning to add 3850 to the existing 3750 stack?
The latter part is not possible since 3850's and 3750's have different stacking modules and cables.
In both the cases, since the 3750's are due for EOL, I ain't sure if the task you are attempting would suffice your requirement.
My suggestion would be to plan on seamless hardware upgrade of all your 3750's.
ASKER
Mr. BC74,
You are absolutely right.
What I want to do is trunking my current 3750 Stack with one 3850.
I need you to please explain a little bit more.
So let's analyze the code you sent me.
3750_STACK
!
// Is this to create the channel-group 1?
interface Porth-Channel1
description UPLINK-TO-SWITCH-2
switchport mode trunk
switchport nonegotiate
end
!
// And now this is to assign the channel to port Gi0/1???
interface Git0/1
description UPLINK-TO-SWITCH-2
switchport mode trunk
channel-group 1 mode active
And after the configuration I just have to connect both ports with a regular patch cord?
You are absolutely right.
What I want to do is trunking my current 3750 Stack with one 3850.
I need you to please explain a little bit more.
So let's analyze the code you sent me.
3750_STACK
!
// Is this to create the channel-group 1?
interface Porth-Channel1
description UPLINK-TO-SWITCH-2
switchport mode trunk
switchport nonegotiate
end
!
// And now this is to assign the channel to port Gi0/1???
interface Git0/1
description UPLINK-TO-SWITCH-2
switchport mode trunk
channel-group 1 mode active
And after the configuration I just have to connect both ports with a regular patch cord?
You need to have the same configuration on the 3850 too, and then connect the physical ports. You should be up and running.
ASKER
What do you mean the same configuration?
Create the same VLANs with the same numbers?
All of the ports in the new Switch will belong to the VLAN 1 only.
But I have 4 other VLANs configured in the Cisco 3750 Stack.
Create the same VLANs with the same numbers?
All of the ports in the new Switch will belong to the VLAN 1 only.
But I have 4 other VLANs configured in the Cisco 3750 Stack.
These are not vlans, they are port-channels and trunk ports you are creating. Trunk ports carry the various vlans, port-channels create logical port bundles that belong to a same group.
ASKER
Thank you very much guys.
Trunking between the 3750 Stack and the new 3850 using etherchannel.
Trunking between the 3750 Stack and the new 3850 using etherchannel.
This should be done regardless for redundancy.