How to connect CISCO 3750 thru Stack cable

[ZAHIDHASEEB]

1- Currently we have two switches with same IOS. Do we only require to connect both switches physically thru stack cable ? or we need to configure both switches too on IOS ? 

2- Do both switches work as a single logical switch and load will be distributed if we connect all hosts machines to both switches with a 50/50 ratio ?

[Leo Laohoo]

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@ZAHIDHASEEB wrote:

Do we only require to connect both switches physically thru stack cable ? or we need to configure both switches too on IOS

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It is all up to you.  People buy 3750 series switches because they want to use the stacking capability.  If you do not want or need to stack it then you do not need to.  Whatever floats your boat.  

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@ZAHIDHASEEB wrote:

Do both switches work as a single logical switch and load will be distributed if we connect all hosts machines to both switches with a 50/50 ratio

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Again, depends on how the hosts are connected.  Are the link in an etherchannel or not?  Are the hosts connected via single link or multiple?  

[ZAHIDHASEEB]

Actually we have a single layer-III Core switch in our Infrastructure which seems over loaded. We also have a layer-III switch with same IOS available in a backup which is currently not connected with Network/LAN. So we need to make a stack of both switches so that we can make a single logical switch which can help us to transfer/balance the load on single switch to two switches.

[balaji.bandi]

here is good stacking guide :

https://www.cisco.com/c/en/us/support/docs/switches/catalyst-3750-series-switches/71925-cat3750-create-switch-stks.html

basic rule, bot the models need to support and compatable.

IOS version should be same.

make the switch number and pririty to master and slave

always use dual uplink to core, which each can go Switch 1 and Switch 2 (to avaoide failures).

2- Do both switches work as a single logical switch and load will be distributed if we connect all hosts machines to both switches with a 50/50 ratio ?

Stack Physically 2 ( and Logically 1)

the load depends on the end device connection, Port-channel config ..so on

[Giuseppe Larosa]

Hello @ZAHIDHASEEB ,

there are some best practices about C3750 stack configuration that are optional but they can help in network stability over time.

they are about :

configuring a priority  ( default 1 highest value 15, higher value is preferred) for a switch member ot make master election more deterministic.

Configuring MAC address persistency: by default in case the master switch changes it would use its own set of MAC addresses but this would make the change visible to the outer world it is possibile to configure mac address persistency even with a infinite time ( using 0) so that in case of master change the new master will use the same set of MAC addresses used by the previous master and this makes the change not visible to outer world ( except for some links that can be failed if the previos master is not operational or powered off).

You can also provision the switch members to associate a specific switch number to a specific device identified by model and serial number.

2)   if you have hosts on both switches as noted by @Leo Laohoo it depends on how these hosts are connected if they are multihomed using a port-channel on both member switches or not. In general traffic between single homed hosts will go via the stack ring,

Traffic to outer world should use the uplink on the same member switch even if it is part of a port-channel ( multi chassi port channel are supported) to minimize use of the stack ring.

Configuration is only one and stored and managed on the master switch . Ports are identified as X/0/y where X is the member switch and y is the port on the member switch like gi1/0/20 and gi2/0/4.

Hope to help

Giuseppe

[ZAHIDHASEEB]

1- How to configure a priority ? (any step by step configuration)

2- Host are not multi home.

[Giuseppe Larosa]

Hello @ZAHIDHASEEB ,

you can use the link provided by @balaji.bandi 

https://www.cisco.com/c/en/us/support/docs/switches/catalyst-3750-series-switches/71925-cat3750-create-switch-stks.html

It explains how to configure and manage a C3750 stack.

switch 1 priority 15

Hope to help

Giuseppe

[ZAHIDHASEEB]

Thanks members for your words. I saw the section "Tips to Add a Switch as a Slave to the Stack" from the above provided link and understood it. Just one more query:

Do we need to restore the configurations of LIVE Core switch on switch which is going to be added as Slave ? (means both switches which will be in stack will have same configurations) ? 

[balaji.bandi]

Technically - if you adding switch to existing stack, there is no need configuration, Switch Master have all the config, (you need to do basic config as suggested)

if you building new Stack, then you need to configure as per network rquirement,

[ZAHIDHASEEB]

As I describe that currently we have one Core Switch at our Production. Does the switch has a default Stack configured ? or the Stack need to create first time ?

[balaji.bandi]

Technically - if you adding switch to existing stack, there is no need configuration, Switch Master have all the config, (you need to do basic config as suggested)

Not sure what is not clear here - If you adding new device to exiting switch, you need to basic config (on the new switch) join to the Live device to form stack ( if you are more cautious and doing first time, Do in maintenance window)

For clarity here is the steps :

Take the current running config out of the box (means backing up the config and keeping safe, for emergency use)

Step 1) On the Current switch give the global command: switch stack-member-number provision type

Type is the type of switch you are adding to the stack.

When adding for example a third Cisco switch to the Cisco stack, use the following command:

switch 2 provision ws3750g-XX - change the model of the switch here

Offline Prepare the Stack member.

Basic config

change the priority (Lower than exiting one - if exiting one do not have, make it highest number like 15) and the new 14 or less
change the switch number (new and old one as mentioned in the URL document)
save the config

Step 2) Power off the new stack member
Step 3) Connect the new member to the Cisco stack using the stacking cables, 1 loop at a time.
Step 4) Power on the new stack member.

check stack member join the stack, issuing a command show switch

[ZAHIDHASEEB]

I have configured cisco stack (Stack-1 port of switch-1 to Stack-2 port of Switch-2 and Stack-2 port of switch-1 to Stack-1 port of Switch-2 ). Now I noticed that ping is not good when my endpoint computers are pinging to our LAN gateway or other VLAN machines. Further, how can I increase the stackwise ring speed to full(32G) instead of half(16G)

#sh switch stack-ring speed

Stack Ring Speed : 16G
Stack Ring Configuration: Half
Stack Ring Protocol : StackWisePlus

[balaji.bandi]

Post below output

show switch
show switch details
 show version
show license all switch 1
show license all switch 2

then the stack formed, the Stack ring show you 32GB, which means something wrong here.

what is the console Logs apart from the above asked oputputs

[ZAHIDHASEEB]

#show switch
Switch/Stack Mac Address : 6416.8d98.ac80
H/W Current
Switch# Role Mac Address Priority Version State
----------------------------------------------------------
1 Member 0000.0000.0000 0 1 Removed
*3 Master 6416.8d98.ac80 15 1 Ready
4 Member 30e4.dbcb.af80 1 1 Ready

#show switch detail
Switch/Stack Mac Address : 6416.8d98.ac80
H/W Current
Switch# Role Mac Address Priority Version State
----------------------------------------------------------
1 Member 0000.0000.0000 0 1 Removed
*3 Master 6416.8d98.ac80 15 1 Ready
4 Member 30e4.dbcb.af80 1 1 Ready

Stack Port Status Neighbors
Switch# Port 1 Port 2 Port 1 Port 2
--------------------------------------------------------
3 Down Ok None None
4 Ok Down 3 None

#show version
Cisco IOS Software, C3750E Software (C3750E-UNIVERSALK9-M), Version 12.2(55)SE11, RELEASE SOFTWARE (fc3)
Technical Support: http://www.cisco.com/techsupport
Copyright (c) 1986-2016 by Cisco Systems, Inc.
Compiled Wed 17-Aug-16 12:20 by prod_rel_team
Image text-base: 0x00003000, data-base: 0x02800000

ROM: Bootstrap program is C3750E boot loader
BOOTLDR: C3750E Boot Loader (C3750E-HBOOT-M) Version 12.2(44r)SE3, RELEASE SOFTWARE (fc3)

TPSCORE uptime is 9 hours, 47 minutes
System returned to ROM by power-on
System restarted at 12:29:43 utc Wed Aug 11 2021
System image file is "flash:c3750e-universalk9-mz.122-55.SE11.bin"

This product contains cryptographic features and is subject to United
States and local country laws governing import, export, transfer and
use. Delivery of Cisco cryptographic products does not imply
third-party authority to import, export, distribute or use encryption.
Importers, exporters, distributors and users are responsible for
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to comply with U.S. and local laws, return this product immediately.

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If you require further assistance please contact us by sending email to
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License Level: ipbase
License Type: Permanent
Next reload license Level: ipbase

cisco WS-C3750E-24TD (PowerPC405) processor (revision G0) with 262144K bytes of memory.
Processor board ID FDO1347V02X
Last reset from power-on
16 Virtual Ethernet interfaces
1 FastEthernet interface
84 Gigabit Ethernet interfaces
6 Ten Gigabit Ethernet interfaces
The password-recovery mechanism is enabled.

512K bytes of flash-simulated non-volatile configuration memory.
Base ethernet MAC Address : 64:16:8D:98:AC:80
Motherboard assembly number : 73-11177-13
Motherboard serial number : FDO13470KZB
Model revision number : G0
Motherboard revision number : A0
Model number : WS-C3750E-24TD-S
Daughterboard assembly number : 800-29737-01
Daughterboard serial number : FDO134706JA
System serial number : FDO1347V02X
Top Assembly Part Number : 800-28924-01
Top Assembly Revision Number : C0
Version ID : V03
CLEI Code Number : COMSE00ARB
Hardware Board Revision Number : 0x00

Switch Ports Model SW Version SW Image
------ ----- ----- ---------- ----------
* 3 30 WS-C3750E-24TD 12.2(55)SE11 C3750E-UNIVERSALK9-M
4 30 WS-C3750E-24TD 12.2(55)SE1 C3750E-UNIVERSALK9-M

Switch 04
---------
Switch Uptime : 2 hours, 22 minutes
Base ethernet MAC Address : 30:E4:DB:CB:AF:80
Motherboard assembly number : 73-11177-14
Motherboard serial number : FDO15261FHQ
Model revision number : M0
Motherboard revision number : C0
Model number : WS-C3750E-24TD-S
Daughterboard assembly number : 73-11426-02
Daughterboard serial number : FDO15251VQC
System serial number : FDO1525Y4L3
Top assembly part number : 800-28924-04
Top assembly revision number : E0
Version ID : V05
CLEI Code Number : COMCF00ARB
Daughterboard revision number : A0
License Level : ipbase
License Type : Permanent
Next reboot licensing Level : ipbase

Configuration register is 0xF

# show license all switch 1
% Slot 1 does not exist or is not licensable

#show license all switch 2
% Slot 2 does not exist or is not licensable

#show license all switch 3
License Store: Primary License Storage
StoreIndex: 0 Feature: ipbase Version: 1.0
License Type: Permanent
License State: Active, In Use
License Priority: Medium
License Count: Non-Counted

License Store: Evaluation License Storage
StoreIndex: 0 Feature: ipservices Version: 1.0
License Type: Evaluation
License State: Active, Not in Use, EULA not accepted
Evaluation total period: 8 weeks 4 days
Evaluation period left: 8 weeks 4 days
License Priority: None
License Count: Non-Counted

#show license all switch 4
License Store: Primary License Storage
StoreIndex: 0 Feature: ipbase Version: 1.0
License Type: Permanent
License State: Active, In Use
License Priority: Medium
License Count: Non-Counted

License Store: Evaluation License Storage
StoreIndex: 0 Feature: ipservices Version: 1.0
License Type: Evaluation
License State: Active, Not in Use, EULA not accepted
Evaluation total period: 8 weeks 4 days
Evaluation period left: 8 weeks 4 days
License Priority: None
License Count: Non-Counted

[ZAHIDHASEEB]

Today I lose the screw and re-plugged stack cables. Now the ring is complete. Dont know what happen

#sh switch stack-ring speed

Stack Ring Speed : 32G
Stack Ring Configuration: Full
Stack Ring Protocol : StackWisePlus