Connection between ISP Routers and Cisco switches

[mmarie]

Hello, 

We have four ISP's routers was connected directly to SDWAN, and we will change the connection to be connect to SDWAN via Cisco switches, as the below diagram:

Here is the configuration for two ISP's

-ISP1 Router side:

interface GigabitEthernet0/0/0.400
encapsulation dot1Q 400
ip address 10.221.27.42 255.255.255.252
end

-ISP1 switch side:

interface GigabitEthernet1/0/4
description ISP1-SDWAN1
switchport access vlan 400

---------------------------------------

-ISP2 Router side:

interface GigabitEthernet0/0/0.300
encapsulation dot1Q 300
ip address 172.110.25.94 255.255.255.252
end

-ISP1 switch side:

interface GigabitEthernet2/0/4
description ISP2-SDWAN1
switchport access vlan 300

So, the ports configuration is correct or not?

Appreciate your help. 

Thanks

[Kasun Bandara]

@mmarie hello, if you using encapsulation at router side, use trunk mode in switch port and configure access port with correct vlan in the interface which connects to firewall.

[balaji.bandi]

that should work - make sure SD-WAN Router connected interface also belong to same VLAN.

[MHM Cisco World]

No need subinterface in ISP if you connect it via access port to SW.

MHM

[mmarie]

I configure them as access mode with VLAN for each ISP and working fine but getting notification "%CDP-W-NATIVE_VLAN_MISMATCH: Native VLAN mismatch detected on interface"

So should i ignore it?

Thanks

[MHM Cisco World]

friend 
ISP send tag frame since you use subinterface
SW forward UNtag frame since you config it as access 
and that why  CDP mismatch appear 
you need to run ISP wihtout Subinterface

MHM

[mmarie]

@MHM Cisco World Thank you for your feedback

We cannot make any change at ISP router because its accessible from Internet provider only, so just can change the switch configuration. 

So can i ignore the CDP mismatch, or that will make any issue.

Thanks 

[MHM Cisco World]

Some SW accept tag frame in access port, if you have no problems with connection (can ping acess internet) then you can ignore cdp

MHM

[mmarie]

Should i ask the ISP to adding the below command under the interface. "encapsulation dot1q 300native" as the current only "encapsulation dot1Q 300" as below

interface GigabitEthernet0/0/0.300
encapsulation dot1Q 300

Thanks

[MHM Cisco World]

Sure that can solve issue' both misconfig and cdp native mismatch

Goodluck 

MHM

[maryam62994]

I set them up in access mode with VLANs assigned for each ISP, and everything is functioning properly. However, I'm receiving a notification indicating a native VLAN mismatch on the interface. Should I disregard this notification? Thank you. alight motion xml file download apk

[balaji.bandi]

because you using trunk if the native VLAN different you get that message, that is just warning, you can use log discriminator to suppress the logs, if both the side have different native vlan. (i wont believe some provider do not give that information) on your side if you not mentioned default vlan1.