Migration from Cisco 3750 Stack to Meraki 9300M CS 16.8 – Questions Regarding Port-Channels

[athan1234]

Hi everyone,

I’m currently working on a migration project for one of my customers, transitioning their network from a Cisco 3750 stack to a Meraki 9300M  CS 16.8  environment.

The current setup includes 3 Cisco 3750 switches in a stack, with 12 port-channels configured in "mode on" for EtherChannel. In the Meraki environment, I have configured link aggregation accordingly.

I have a couple of questions:

1. Compatibility of "mode on":
   On the 3750s, all EtherChannels are configured using channel-group <X> mode on. On the Meraki side, I have configured link aggregation. Is it correct to use Meraki aggregation with "mode on" on the Cisco 3750 side, or is there a better recommended configuration?

2. Cross-stack port-channels:
   On the 3750 stack, several port-channels are configured using interfaces from different physical switches. For example:

   Port-channel 1:
   - Gi2/0/13 (Switch 2)
   - Gi3/0/13 (Switch 3)

   Port-channel 3:
   - Gi2/0/1 (Switch 2)
   - Gi3/0/1 (Switch 3)

   Port-channel 13:
   - Gi1/0/11 (Switch 1)
   - Gi2/0/11 (Switch 2)
   - Gi3/0/11 (Switch 3)

   Port-channel 15:
   - Gi1/0/5 (Switch 1)
   - Gi2/0/17 (Switch 2)
   - Gi3/0/17 (Switch 3)

   In the new Meraki 9300M setup, it appears that cross-switch (cross-stack) aggregation is not supported in the same way. Is it required that all member interfaces of a port-channel be on the same physical Meraki switch?

For example, in the Meraki setup, I believe it would need to be restructured like this:

• Port-channel 1:

  • Current (3750): Gi2/0/13 + Gi3/0/13

  • New (Meraki): Gi2/0/13 + Gi2/0/25 (if available)

• Port-channel 3:

  • Current (3750): Gi2/0/1 + Gi3/0/1

  • New (Meraki): Gi2/0/1 + Gi2/0/26

I would appreciate any confirmation or recommendations on how to best approach this in the Meraki environment.

[Blue_Bird]

https://documentation.meraki.com/MS/Deployment_Guides/Getting_started%3A_Cisco_Catalyst_9300_Managem...

https://documentation.meraki.com/General_Administration/Tools_and_Troubleshooting/Link_Aggregation_a...

Thanks

[athan1234]

I was reading the document you sent me, which is why I opened this ticket. I have some doubts and need to clarify my questions. The management will be through Meraki Cloud Management

[alemabrahao]

Meraki only supports LACP for link aggregation, It does not support static (mode on) EtherChannels.
You must change the EtherChannel configuration on the Cisco 3750 side from mode on to mode active.

You can do link aggregation in Merki on different switches in the stack without any problem.

[athan1234]

thanks @alemabrahao 

I have a question: if I configured Link Aggregation (port-channel) on a Catalyst 9300 M , and the other switches maybe are  a Cisco 2960 (or a non-Meraki switch), and the port-channel is currently set to mode "on", do I need to change the mode to "active"?

[GIdenJoe]

Yes the remote switches will have to move from mode on to mode active or mode passive to enable LACP negotiation.  This will mean you will have a temporary hickup on those switches when you remove the mode on version and move to the mode active/passive.

When you finally move your C9300-M switches to the native IOS-XE versions you will be able to see the running config via dashboard and you will see how the port-channels are created.

[alemabrahao]

Yes, you do, as switches managed via Meraki Cloud do not support mode on.

[athan1234]

Hi, thanks. @alemabrahao  and @GIdenJoe 

I have some doubts regarding this migration process and would appreciate your advice.

Currently, my customer has a switch (SW1) with all fiber connections, and switches 2 and 3 are connected using different port-channels and regular ports.

The Meraki MS9300 has three modules with 8 fiber ports each. I’ll need to move these fiber connections from the Cisco switches to the Merakis, and I also need to connect to a copper-based port-channel.

Regarding the migration, what is the best approach?

Should I power on all Meraki switches and then migrate the cables one by one from the Cisco switches to the Merakis? Would it be better to start by migrating the fiber connections first, and then move on to the port-channels?

Also, when migrating the port-channels, is it better to move one link at a time and adjust the configuration on the Cisco side (e.g., LACP negotiation: active/passive)? Or should I change the negotiation mode first before moving the cables?

[alemabrahao]

It's best to power on the Meraki switches first. For Cisco switches, it's best to move the connections simultaneously. So, the best option is to run it during a maintenance window, disconnect the connections, access the switch via the CLI (console), change the portChannel configuration, and then move the connections to the Meraki switch.

Run all the tests and then move to the new switch. There's no shortcut; just run one at a time and everything will be fine.

[athan1234]

Thanks @alemabrahao In your opinion, what would you choose for the first step: migrating all the fiber connections first and then the port-channel, or starting with the port-channel and, once it's fully migrated, moving on to the fiber?

[alemabrahao]

I generally prefer to configure the port channel and then remove the connections.

[athan1234]

Hello,

I’ve encountered a couple of issues that I’d like to discuss with you. The problem involves port channel aggregation on Cisco 2960 switches. I was trying to configure the port channel using "mode on," but the port channel remained in a (P) (P) state without any connection.

When I changed the mode to "active," the port channel still didn’t come up. To get connectivity, I had to remove the aggregation and leave the interfaces without a port channel.

Do you have any ideas or solutions to resolve this? Could it be a bug in the 2960 firmware version? I'm not sure.

I attach the logs 2960 

Log Buffer (4096 bytes):
erface GigabitEthernet0/1, changed state to up
*Mar 12 09:23:24: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan130, changed state to up
*Mar 12 09:23:54: %SPANTREE-2-RECV_PVID_ERR: Received BPDU with inconsistent peer vlan id 126 on GigabitEthernet0/1 VLAN1.
*Mar 12 09:23:54: %SPANTREE-2-BLOCK_PVID_PEER: Blocking GigabitEthernet0/1 on VLAN0126. Inconsistent peer vlan.
*Mar 12 09:23:54: %SPANTREE-2-BLOCK_PVID_LOCAL: Blocking GigabitEthernet0/1 on VLAN0001. Inconsistent local vlan.
*Mar 12 09:23:54: %SPANTREE-2-RECV_PVID_ERR: Received BPDU with inconsistent peer vlan id 126 on GigabitEthernet0/2 VLAN1.
*Mar 12 09:23:54: %SPANTREE-2-BLOCK_PVID_PEER: Blocking GigabitEthernet0/2 on VLAN0126. Inconsistent peer vlan.
*Mar 12 09:23:54: %SPANTREE-2-BLOCK_PVID_LOCAL: Blocking GigabitEthernet0/2 on VLAN0001. Inconsistent local vlan.
*Mar 12 09:23:54: %SW_MATM-4-MACFLAP_NOTIF: Host 0c23.692b.f552 in vlan 504 is flapping between port Gi0/1 and port Gi0/2
*Mar 12 09:23:54: %SW_MATM-4-MACFLAP_NOTIF: Host e455.a801.5471 in vlan 500 is flapping between port Gi0/1 and port Gi0/2
*Mar 12 09:23:54: %SW_MATM-4-MACFLAP_NOTIF: Host e455.a82a.8287 in vlan 119 is flapping between port Gi0/1 and port Gi0/2
*Mar 12 09:23:54: %SW_MATM-4-MACFLAP_NOTIF: Host e455.a801.53f2 in vlan 500 is flapping between port Gi0/1 and port Gi0/2
*Mar 12 09:23:54: %SW_MATM-4-MACFLAP_NOTIF: Host 009c.02a3.7126 in vlan 110 is flapping between port Gi0/2 and port Gi0/1
*Mar 12 09:23:54: %SW_MATM-4-MACFLAP_NOTIF: Host 0018.0a4f.0001 in vlan 119 is flapping between port Gi0/1 and port Gi0/2
*Mar 12 09:23:54: %SW_MATM-4-MACFLAP_NOTIF: Host c025.a532.b7d1 in vlan 116 is flapping between port Gi0/2 and port Gi0/1
*Mar 12 09:23:54: %SW_MATM-4-MACFLAP_NOTIF: Host 00be.7564.de8c in vlan 121 is flapping between port Gi0/1 and port Gi0/2
*Mar 12 09:23:54: %SW_MATM-4-MACFLAP_NOTIF: Host 5838.797f.df42 in vlan 120 is flapping between port Gi0/1 and port Gi0/2
*Mar 12 09:23:54: %SW_MATM-4-MACFLAP_NOTIF: Host 009c.02a3.7126 in vlan 110 is flapping between port Gi0/1 and port Gi0/2
*Mar 12 09:23:54: %SW_MATM-4-MACFLAP_NOTIF: Host e455.a801.5471 in vlan 500 is flapping between port Gi0/2 and port Gi0/1
*Mar 12 09:23:54: %SW_MATM-4-MACFLAP_NOTIF: Host e455.a801.53f2 in vlan 500 is flapping between port Gi0/1 and port Gi0/2
*Mar 12 09:23:54: %SW_MATM-4-MACFLAP_NOTIF: Host 0c23.692b.f552 in vlan 504 is flapping between port Gi0/1 and port Gi0/2
*Mar 12 09:23:55: %SW_MATM-4-MACFLAP_NOTIF: Host 0018.0a4f.0001 in vlan 109 is flapping between port Gi0/1 and port Gi0/2
*Mar 12 09:23:55: %SW_MATM-4-MACFLAP_NOTIF: Host 387c.7607.a9ec in vlan 116 is flapping between port Gi0/1 and port Gi0/2
*Mar 12 09:23:55: %SW_MATM-4-MACFLAP_NOTIF: Host 6400.6a8f.5dcc in vlan 119 is flapping between port Gi0/1 and port Gi0/2
*Mar 12 09:23:55: %SW_MATM-4-MACFLAP_NOTIF: Host f8dc.7a3a.9a3e in vlan 119 is flapping between port Gi0/1 and port Gi0/2
*Mar 12 09:23:55: %SW_MATM-4-MACFLAP_NOTIF: Host 0018.0a4f.0001 in vlan 116 is flapping between port Gi0/1 and port Gi0/2
*Mar 12 09:23:56: %SW_MATM-4-MACFLAP_NOTIF: Host a846.9d27.c382 in vlan 500 is flapping between port Gi0/2 and port Gi0/1
*Mar 12 09:27:09: %SW_MATM-4-MACFLAP_NOTIF: Host a846.9d27.c36a in vlan 500 is flapping between port Gi0/1 and port Fa0/19

[alemabrahao]

When I say reconfigure, I mean deleting the port channel settings and configuring everything again.

On the Catalyst switch, you need to run the "default interface gix/x/x" command to reset the configuration.

Remove the current port channel with the "no port channelx" command.

Create the new port channel

and then associate the interface with the on mode.

[alemabrahao]

Could you also share the interface and port channel configurations of the Catalyst 2960 and Meraki as well?

[athan1234]

HI thanks for your reply 

On the 2960 side, I removed the EtherChannel. It was configured on interfaces G0/1 and G0/2 as Port-Channel 1.

I attached the vlan customer 

1 default active
21 VLAN_VOZ active Fa0/1, Fa0/2, Fa0/3, Fa0/4, Fa0/5, Fa0/6, Fa0/7, Fa0/8, Fa0/9, Fa0/10, Fa0/11, Fa0/12, Fa0/13, Fa0/14, Fa0/15, Fa0/16, Fa0/17, Fa0/18, Fa0/20, Fa0/21, Fa0/22
Fa0/23, Fa0/24
66 CCTV active
88 CATO active
89 VLAN0089 active
101 VLAN_MACROLAN active
102 VLAN_INTERNET active
103 VLAN_DMZ active
104 VLAN_FW active
109 VLAN_SEGURIDAD active
110 VLAN_SERVIDORES active
111 VLAN_SERVIDORES_APP active
112 VLAN_BBDD active
113 VLAN_P2_IZQ active
114 VLAN_P2_DER active
115 VLAN_P1 active Fa0/1, Fa0/2, Fa0/3, Fa0/4, Fa0/5, Fa0/6, Fa0/7, Fa0/8, Fa0/9, Fa0/10, Fa0/11, Fa0/12, Fa0/13, Fa0/14, Fa0/15, Fa0/16, Fa0/17, Fa0/18, Fa0/20, Fa0/21, Fa0/22
Fa0/23, Fa0/24
116 VLAN_P0_IZQ active
117 VLAN_P0_DER active
118 VLAN_SOTANO active
119 VLAN_ALMACEN active
120 VLAN_IMPRESORAS active
121 WLAN_Taller active
122 WLAN_Silo active
123 WLAN_Oficina active
124 WLAN_Invitados active
125 WLAN_Dispositivos active
126 VLAN_TRANS_WIRELESS active
130 GESTION active
131 VLAN_ISCSI active
132 VLAN_CENTRALITA active
133 VLAN_MANTENIMIENTO active
200 KIALA active
300 PLATAFORMA_LOGISTICA active
500 VLAN_GESTION_WIFI active
502 WLAN_WIFI_BOYACA active
504 WLAN_WIFI_ALMACEN active
505 WLAN_Presidencia active
507 Vlan_test_Infra active
999 TELEFONICA active
1002 fddi-default act/unsup
1003 token-ring-default act/unsup
1004 fddinet-default act/unsup
1005 trnet-default act/unsup

Group Port-channel Protocol Ports
------+-------------+-----------+-----------------------------------------------
1 Po1(SD) -

2960-1-d-02#show run interface gigabitEthernet 0/1
Building configuration...

Current configuration : 90 bytes
!
interface GigabitEthernet0/1
description 3750-Bbone-Core01
switchport mode trunk
end

2960-1-d-02#show run interface gigabitEthernet 0/2
Building configuration...

Current configuration : 90 bytes
!
interface GigabitEthernet0/2
description 3750-Bbone-Core01
switchport mode trunk
end

I created an EtherChannel and added the VLANs.
(I deleted the EtherChannel so I could share the setup with you.)

I had created an EtherChannel using two ports from different switches in the stack.
Each port had the following configuration:

[alemabrahao]

The correct way is to reset the interfaces, create the port channel, associate the interfaces with the port channel, and then apply the other settings directly to the port channel.

default interface gi0/1

default interface gi0/2

interface portchannel1

exit

interface range gi0/1,gi0/2

channel group 1 mode active

exit

interface portchannel1

switch port mode trunk

spanning-tree link-type point-to-point

[athan1234]

Mode on? Sure? Maybe it's active in 2960 mode, isn't it?

[alemabrahao]

Sorry, force of habit, active mode.