Single Mode to Multi Mode pass through configuration

CjD2018 · ‎01-03-2022

I have a 9300 Access switch that is located between two fobots, one fobot is single mode and the other is multi mode.

Upstream on the single mode is the Core switch, downstream from the Access switch, on the multi mode is a Distribution switch.

I want to pass the Core switch's connection through the Access switch and through to the Distribution switch.

On the Access switch the existing vlans are (lets say) 2,3,4,5,6.

On the Distribution switch, it has the above vlans as well as the following VRFs: 200,300,400,500,600.

What configuration is required on the Access switch to make this possible?

Thank you for your help.

Leo Laohoo · ‎01-03-2022

vlan 2
vlan 3
vlan 4
vlan 5
vlan 6
vlan 7
vlan 8
vlan 9
vlan 10
interface range <PORTS>
 description Trunk
 switchport mode trunk
 switchport trunk native vlan <NATIVE VLAN>
 switchport trunk allowed vlan 2,3,4,5,6,7,8,9,10
 udld port aggressive

@CjD2018 wrote:

On the Distribution switch, it has the above vlans as well as the following VRFs: 200,300,400,500,600.

Only the Distro will "understand" VRF. Access switches do not understand VRF.

VRF are assigned to the VLANs.

interface Vlan2
 description VRF 2
 ip vrf forwarding 200
 ip address 2.2.2.2 255.255.255.0
 ip helper-address 1.1.1.1
 ip helper-address 2.2.2.2
 logging event link-status

CjD2018 · ‎01-03-2022

Hi Leo, regarding that only the DS will understand VRFs, how will the DS know which trunk to use to reach the core? Wouldn't the between access switch have to be configure to show the DS that it has access to the core?

CjD2018 · ‎01-03-2022

Hi Leo, regarding that only the DS will understand VRFs, how will the DS know which trunk to use to reach the core?

Wouldn’t the between access switch have to be configure to show the DS that it has access to the core?

Leo Laohoo · ‎01-03-2022

@CjD2018 wrote:

how will the DS know which trunk to use to reach the core?

Read my response carefully -- I have provided the answer to this question.

@CjD2018 wrote:

Wouldn’t the between access switch have to be configure to show the DS that it has access to the core?

Read my response carefully -- I have provided the answer to this question.

CjD2018 · ‎01-03-2022

interface vlan 2

ip vrf forwarding 200

I see.... on the DS it already has an interface ip vrf forwarding address for vlan 2 and a interface ip vrf forwarding address for 200. The 200 also has ospf network point-to-point setup. Will I need to setup OSPF on the between access switch to make this work?

Leo Laohoo · ‎01-03-2022

@CjD2018 wrote:

Will I need to setup OSPF on the between access switch to make this work?

WTF are you trying to do?

Are you passing VLANs or are you trying to route?

CjD2018 · ‎01-03-2022

What I would like to do is on the in between access switch is to pass through everything on one port through to another port.

So that the core and the DS don't see the AS in between and the AS still act as though it is a regular AS switch connected to the DS.

I getting the feeling that this may not be possible.

mlund · ‎01-04-2022

Hi

I may be totally misunderstanding this, but for me it sounds like the config is like this.

Core-switch with lots of vlans

interface on core pointing towards AccessSwitch,

interface on AS towards core , with allow vlan 2,3,4,5,6

AS with vlans configured , with vlans configured 2,3,4,5,6

interface on AS towards DS , with allow vlan 2,3,4,5,6

interface on DS towards AS, with allow vlan ??

DS with vlans configured , 2,3,4,5,6,200,300,400,500,600

If this is what you have and if you wan't to get the vlans 200-600 to go through AS to core, then you have to configure on AS

vlan 200

vlan 300

vlan 400

vlan 500

vlan 600

on both interfaces, switch trunk all vl add 200,300,400 and so on, also on core interface this may be needed

/Mikael

CjD2018 · ‎01-04-2022

Sorry Guys, apparently I have been looking at this all wrong and making it appear more complicated than it should be.

The simple solution is on the in between access switch, to make pass through ports that use their own vlan.

First, on the in between access switch create a vlan with a friendly named like Pass_Through.

vlan 3000
name Pass_Through

Next, configure ports on the in between access switch that connect to the core and to the DS, using this new vlan.

interface TenGigabitEthernet1/1/8

description To the core
switchport trunk allowed vlan 3000
switchport mode trunk

interface TenGigabitEthernet1/1/7

description To the DS
switchport trunk allowed vlan 3000
switchport mode trunk

There is no need to worry about the other existing vlans on the in between switch, because vlan 3000 will carry all the communication back and forth between the core and DS. The in between switch still has its own local trunk, for example T1/1/1, that connects to the DS and allows it to perform its access switch type tasks using the 2,3,4,5 & 6 vlans.

As for the mulit mode and single mode issue, it is sorted.

PS. It is business hours here so I will have to connect this up out of business hours, I'll let you know how it goes.

CjD2018 · ‎01-05-2022

Fail.