Failover Possilities on a Dell 6248 Layer 3 Switch

FlintAdmin
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Hello experts,

I am looking for possibilities of making a redundant/failover connection on a Dell PowerConnect 6248 switch. I am not 100% sure if this can even be done but here is my scenario.

I am currently installing a second/redundant fiber link into or main office from a satellite office and I know that there are devices out there that I can run both links into and create a failover environment. However I am questioning whether or not our current Dell switch can handle this process with out purchasing any additional hardware. I would like to be able to set up the switch to run the main link unless the link is broken and then failover to the second link.

I have looked a little at Link Aggregation, and I may be wrong, but that seem like it will still use both links. Just getting started here and any help is greatly appreciated

Thanks
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Commented:
what kind of links do you have between your offices? dark fiber, speeds?
what type of equipment you have in your branch? switch or router?

there are many ways how to improve your redundancy: with another switch, with link aggregation, with vrrp, etc.

Author

Commented:
Currently we have a 40gb fiber connection between the two offices. The link comes into a fiber module and then into a layer3 dell switch on both ends.

We are adding a second link between the two offices that will be mircowave to fiber and again to another layer3 dell switch. I understand that we can purchase extra equipment, but I am hoping that there is a way to use our current switch on the originating end for a faliover.

Thanks for your response

Commented:
what is 40gb fiber? what is the media type (1000Base LX, 1000Base SX etc). Is that you fiber from end to end or it is provided by ISP?
can you draw a sketch of your planned topology and current networking equipment.
and then will try to create a redundant solution as possible.
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Author

Commented:
My apology it is a 40gb connection and it is our fiber from end to end.

I don't want to get to far away from my orginal question. What I need to know is if there is a way to bring both connections into the Dell 6248 Switch and create a failover environment.

Is link aggrigation the best option and can you explain how it works?

Thanks
Commented:
still I don't get what is 40gb connection. I know 10/100 Mbps, 1Gbps, 10 Gbps....

Ling aggregation (LAG) works as a charm if you have several lines between your switches. Lines should not have any rate limiting or shaping, and port should have to go down if the line is broken (as an example, when this statement is not true imagine fiber line with media converters (fiber to copper) at both ends. so both switches have cat5 connections and in some cases (depends on media converters) cat5 connection stays up, when fiber line is broken)

I would suggest to use 802.3ad (LACP) protocol between switches, so they could negotiate LAG parameters.
LAG is good because it converges very fast and is logically one link (from a switch's point of view) and under normal conditions throughput can be aggregated (it is not always true, when you have only single host (load sharing is done per IP or MAC) at each side).

However LAG it is not the only technology you have.
You could utilize Spanning tree protocol or you can use L3 redundancy - OSPF routing. In case of OSPF you don't need switch ports to go down, when line goes down. In this case convergence time is longer (ospf route via failed link have to timeout before traffic will flow via second line)



Author

Commented:
Thank you!

With LACP are two physical ports seen as one logical? Can you configure one port as the primary and the other as the secondary? Hence having the secondary connection only used if the primary is brought offline.

Commented:
in both cases answer is positive.

Author

Commented:
Thanks Experts

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