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VLAN and trunk group using LACP

Meterior
Occasional Visitor

VLAN and trunk group using LACP

Dear all,

I have a scenerio like this:
SW2910 Fa1---------Fa1
fa2---------Fa2 SW2910
I configure two VLAN and load balancing over two physical trunk between switches but it doesn't work


Switch1(config)# ip routing
Switch1(config)# trunk 1,2 trk1 lacp
Switch1 (vlan-1)# tagged trk1
Switch1 (vlan-2)# tagged trk1

Switch2(config)# ip routing
Switch2(config)# trunk 1,2 trk1 lacp
Switch2 (vlan-1)# tagged trk1
Switch2 (vlan-2)# tagged trk1

Please help me how can i make i work.
7 REPLIES
Shadow13
Respected Contributor

Re: VLAN and trunk group using LACP

1st i'm not sure why you enabled routing in both switches ?

2nd, can you please specify how "it doesn't work" ?

can you please post the output of "show lacp" from both switches.
Meterior
Occasional Visitor

Re: VLAN and trunk group using LACP

Dear Shadow13,

I think "ip routing" will help routing between 2 vlan on both switches
- The output of lacp, as attached file

Please see and give me solution.

Thanks for all help
Meterior
Occasional Visitor

Re: VLAN and trunk group using LACP

Hi,

Does anyone answer me ?
Jeff Carrell
Honored Contributor

Re: VLAN and trunk group using LACP

So the question still is, what does not work?

Trunking is not "load balancing", it is only "load sharing".

The load sharing algorithm is based on source-destination mac addresses at each switch as it sends to packets across a link in the trunk.

Therefore, sometimes all traffic may go over one link even if there are two links available.

hth...Jeff
Meterior
Occasional Visitor

Re: VLAN and trunk group using LACP

Hi,

Thank Jeff,
It's true. When i show the ip routing on switch2, there was no information about any vlan. I didn't work as you said.
I just wonder if does spanning tree concern with LACP ?




Jeff Carrell
Honored Contributor

Re: VLAN and trunk group using LACP

Meterior asked: "I just wonder if does spanning tree concern with LACP ?"

Spanning tree sees the LACP link as a single link and calculates accordingly.

Added bonus, when you enable spanning tree, the LACP link gets an automatic port cost of 4, which makes it a more favorable link if there additional non-LACP links connecting the 2 switches.

hth...Jeff
Meterior
Occasional Visitor

Re: VLAN and trunk group using LACP

Thanks for all help!