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New Member

LACP over wan

Hi i have this situation.

I have EPL on my MPLS.

Our are cisco stacks.

and routers are ISP provider and i don't have any chance doing with them.

I don't know how much  routers are on the way

In the one DC is 3750X stack on the other DC is 3750X stack between them is LACP protocol.But if the line is break on the way i don't shutdown on my cisco stack and i must wait 1,5minutes then LACP detect broke line and redirect traffic to the other line.

On the 3750X is impossible change LACP timeout.

I think that the solution is IP SLA and ICMP responder between mgmt ip adresss and shutdown interface.But the ICMP traffic go across one line based on hash.

Do you have Any idea?I know the solution is STP but it is the last chance Screen Shot 2012-08-15 at 11.25.12.png

  • WAN Routing and Switching
Everyone's tags (3)
Hall of Fame Super Gold

LACP over wan

Are you running etherchannel? You coudl for example configure Flex links

Or a routing protocol, all these guarantee fast convergence. But Not IP SLA.

New Member

Re: LACP over wan

thank you i try Flex Links, but it doesn't work.CDP it works, but no ICMP or other traffic

Routing protocol is imposible it must be L2

And is it configuration correct?

Stack1 (one Data center)

interface GigabitEthernet1/0/10

description ***Trunk to SCVK***

switchport trunk encapsulation dot1q

switchport mode trunk

switchport backup interface Gi2/0/10

interface GigabitEthernet2/0/10

description ***Trunk to SCVK***

switchport trunk encapsulation dot1q

switchport mode trunk

Stack2 (other data center)

Configuration without change ?

Configuration Flex link is only on one stack?

With this configuration i Have this

vvlansw51        Gig 2/0/10        132              S I   WS-C3750X Gig 1/1/1

vvlansw51        Gig 1/0/10        162              S I   WS-C3750X Gig 2/1/1

vvlansw06#sh interfaces switchport backup detail

Switch Backup Interface Pairs:

Active Interface          Backup Interface          State


GigabitEthernet1/0/10   GigabitEthernet2/0/10   Active Up/Backup Standby

Preemption Mode  : off

Multicast Fast Convergence  : Off

Bandwidth : 1000000 Kbit (Gi1/0/10), 1000000 Kbit (Gi2/0/10)

Mac Address Move Update Vlan : auto

But on the other switch i have this

vvlansw51#sh spanning-tree


  Spanning tree enabled protocol ieee

  Root ID    Priority    32769

             Address     0007.ec01.4480

             Cost        4

             Port        49 (GigabitEthernet1/1/1)

             Hello Time   2 sec  Max Age 20 sec  Forward Delay 15 sec

  Bridge ID  Priority    32769  (priority 32768 sys-id-ext 1)

             Address     649e.f3ce.e200

             Hello Time   2 sec  Max Age 20 sec  Forward Delay 15 sec

             Aging Time  300 sec

Interface           Role Sts Cost      Prio.Nbr Type

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

Gi1/1/1             Root FWD 4         128.49   P2p

Gi2/1/1             Altn BLK 4         128.103  P2p