Solved: Failover in l2 switch

Bikas Giri · ‎10-23-2011

Hi,

I have got a l2 link of 512 kbps from two different ISP. I want to aggegrate the bandwidth of this connection so that I can feel like having 1 mbps connection. I am not actually talking about load balancing, but bandwidth/link aggegration. Can we have the solution of failover with different vlan from different isp ? Can we be able to make the link as a single link.

Bikas

Vaibhava Varma · ‎10-23-2011

Hi Bikas

If we have L2 Links from ISP then the end site Routers/Switch terminate that Link and its in the control of the Site-Devices but not the ISP to aggregate them and yes they can be very well aggregated subject to the type of L2 Connectivity we have taken from ISP.

If its L2-Port Mode Ethernet Link from ISP then there is no issue in aggregation.

But if its L2-VLAN Mode Ethernet Link whereby we are sending tagged frame to ISPs in different VLANs then aggregation will not help us as either of the ISP will be dropping the other VLAN belonging to different ISP on their L2 Link. Had it been same VLANs for both ISP L2-Links we could have been able to aggregate them fine and make use of the bundled links in terms of aggregate Bandwidth.

Hope this answers your query.

Regards

Varma

View solution in original post

Vaibhava Varma · ‎10-23-2011

Hi Bikas

If we have L2 Links from ISP then the end site Routers/Switch terminate that Link and its in the control of the Site-Devices but not the ISP to aggregate them and yes they can be very well aggregated subject to the type of L2 Connectivity we have taken from ISP.

If its L2-Port Mode Ethernet Link from ISP then there is no issue in aggregation.

But if its L2-VLAN Mode Ethernet Link whereby we are sending tagged frame to ISPs in different VLANs then aggregation will not help us as either of the ISP will be dropping the other VLAN belonging to different ISP on their L2 Link. Had it been same VLANs for both ISP L2-Links we could have been able to aggregate them fine and make use of the bundled links in terms of aggregate Bandwidth.

Hope this answers your query.

Regards

Varma

Bikas Giri · ‎10-23-2011

Hi,

The ISP can give both, the port based and vlan based. What should I do to aggegrate the links at my site, will the router or other managable switch help me in this regards.

Bikas

Vaibhava Varma · ‎10-23-2011

Hi Bikas

You can go for a port-based L2 circuit from the two ISPs ( using existing Switch) and do ether-channelling to bundle the two links.Still remember you will need to enable ether-channel load-balancing if we want to utilize both the L2 links optimally.

Please refer the below helpful documentation for same

Ether-Channel Config

http://www.cisco.com/en/US/products/hw/switches/ps628/products_configuration_example09186a00800ef797.shtml

Ether-Channel Load-Balancing

http://www.cisco.com/en/US/tech/tk389/tk213/technologies_tech_note09186a0080094714.shtml

Hope this helps to answer your query

Regards

Varma