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Max2042

2 Posts

5197

February 12th, 2019 23:00

s4148F interswitch traffic within vlan with VLT

Hi,

 

I've set up 2 s4148F's with a VLTi and there are several machines connected with LACP across both switches. So far that's working fine.

Now I'd like to add a non-LAG connection on both switches so 2 devices can talk with each other in their own vlan, like this:

device A <--> (untagged port vlan 100) switch B <-VLTi-> switch C (untagged port vlan 100) <---> device D

in this setup, A and D can not reach each other. I suspect this is because the VLTi can only carry port channel traffic and I'm not setting up a LAG here so I'm not configuring these ports to be in a port-channel.

I have a 100g connection between switch B and C, which is in use for the VLTi. It's not allowed to change the port configuration to trunk, because the VLTi usage won't allow it.

How can I get device A and B to talk with each other?

DELL-Josh Cr

Moderator

 • 

8.5K Posts

February 13th, 2019 10:00

Hi,

Is the VLT link configured to pass VLAN 100? Everything that I have been able to find does talk about it with port channels so that may be the case.

Max2042

2 Posts

February 13th, 2019 23:00

Hi Josh,

The interfaces that the VLT runs over can't be configured to allow vlan 100:

sw-06-of01(config)# vlt-domain 1
sw-06-of01(conf-vlt-1)# show configuration
!
vlt-domain 1
 discovery-interface ethernet1/1/25-1/1/26
 peer-routing
sw-06-of01(conf-vlt-1)# exit
sw-06-of01(config)# interface ethernet 1/1/25
sw-06-of01(conf-if-eth1/1/25)# show configuration
!
interface ethernet1/1/25
 description "VLTi crosslink to sw-07.of01"
 no shutdown
 no switchport
 mtu 9216
 flowcontrol receive off
sw-06-of01(conf-if-eth1/1/25)# switchport trunk allowed vlan 100
% Error: vlan100, Interface being added (to VLAN) is not in switchport mode trunk!.
sw-06-of01(conf-if-eth1/1/25)# switchport mode trunk
% Error: Discovery Interface mode must not be in switchport mode!.

I am wondering what the best practice setup is for these kinds of situations to enable this normal type of traffic to flow through?

 

Thank you,

 

Max

DELL-Josh Cr

Moderator

 • 

8.5K Posts

February 14th, 2019 09:00

Can you private message me the service tag?

sphere011

3 Posts

February 18th, 2019 16:00

Hey there, We are also intersted in this - could you pls share your workaround? Cheers

White_Ninja

1 Rookie

 • 

111 Posts

December 11th, 2019 21:00

yes i would also be interested in the solution.

 

do you put vlan on the discovery interfaces?

remy-ch

26 Posts

December 12th, 2019 07:00

On wich OS(9 / 10)  do you try to configure VLT ?

On 10, you do not have to configure any VLAN.

The VLT "LAG" is using VLAN 4094 which is passing all VLANs by defaut. You must have same VLAN configured on both switchs.

To be sure all is configured correctly, you must check it :

show vlt mismatch

White_Ninja

1 Rookie

 • 

111 Posts

December 12th, 2019 22:00

hi and thanks i am using 10.4.3.6 so all vlans are "trunked" throught vlti connection ports?

remy-ch

26 Posts

December 13th, 2019 03:00

Yes, if there is no configuration mismatch between both switches, VLAN trafic pass VLT interfaces.

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