L2 Failover Plan for Point to Point

[VAbr AVib]

We have 2 point to point links from 2 different ISP's for the purpose of connecting to our data center from our office. We would like to configure a failover scenario using these two P2P links.

I have been trying with the sTP method but for some reason we could not succeed in this, could be because of the distance.

Please help me to implement a failover P2P conectivity usign this two links.

[geraldchow1]

What if using Ospf ? And have 2 point to point links of different bandwidths , would you set the failover using cost ?

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[VAbr AVib]

Jason,

Thanks for the detailed explanation.

Actually we had planned for either STP or Port channel as options to achieve the failover connectivity at L2 layer. The initial impression was that the port channel option might not be supported in a scenario where two different ISP's are enagaged. Now we are in a situation where the STP option is not applicable. Do you see any issue in achieving the port channel when we have two separate ISP ? Will the port channel works in case if ISP using Q-in-Q tagging at their side of the link. ?

[cadet alain · Accepted solution]

Hi,

if you are connected to 2 different L2 devices  then you can't do a port-channel( all links in a port-channel must connect to the same devices).

QinQ is only performed in the ISP cloud so I don't think it should be an issue for you.

Regards

Alain

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[sharonccie · Accepted solution]

I have an idea, is that possible? to configure HSRP between each other (connect two link to two separate switch for switch redundancy in each location) and keep separate traffic in separate VFR, I hope that will work fine, if you going with PortChannel concept you haven’t get switch redundancy, if you want switch redundancy you have to configure either stack or VSS, my suggestion will support both link redundancy and switch redundancy,

Looking forward to hear from you!

[VAbr AVib]

Alain,

Thanks for your query.

Thats not a problem, we will be connecting the links to the same L2 device at both side.

[VAbr AVib]

Sharon,

I am new to HSRP on switch, have done with the routers. But again not sure with L2. Does HSRP work on L2 switch ?

Anyway at this moment we are not looking for switch redundancy, we will just accomplish the link redundancy.

[yusuf habibi]

Hi VAbr

please attach your topology, maybe we can find the solution thx

Regards,

Habibi

[VAbr AVib]

Yusuf,

The topology is simple. We are planning to have a point to point connectivity to the datacenter from our office. For redundancy purpose we are looking for a failover scenario by using two point to point links.

[yusuf habibi]

VAbr,

as long as is connection using layer 2, the stp method can be used.

but for some reason we could not succeed in this, could be because of the distance.

you can using fiber optic for the link connection

in my office having connection to data center with L2

Regards,

Habibi

[sharonccie]

HSRP for L3 only, I still have a doubt about, l2/l3 redundancy is you looking about?

[VAbr AVib]

Sharon,

We are using the L2 switches at both sides of the link.

[VAbr AVib]

Yusuf,

We are using fiber connectivity only. The distance between the two sites is more than 5 Kms and we are using the shared ring loop network of two ISP's using the Q-in-Q mechanism to reach the other site.