topic Re: Dual ISP and ECMP in General Topics

Dual ISP and ECMP

feelgood — Wed, 09 Sep 2020 15:26:17 GMT

Hello,

I have a PA-220 with two links FTTO with same bandwidth (100Mbits/s) from the same ISP (Colt Technology). This two links are configured on my PA-220 with ECMP feature.

Now, I want to take a new ISP for my secondary link (FTTH) in place of my second link from Colt. But it seems to me that ECMP works only with two same links (equal cost) with same bandwidth.

I would like to know if tomorrow I take a second link at another ISP, how could I configure my two links of the same kind (active/active) ? It's possible ?

Thank you in advance for your help.

Best regards.

Re: Dual ISP and ECMP

Abdul-Fattah — Wed, 09 Sep 2020 16:06:29 GMT

Hello,

ECMP feature is made for active links.

is your new link has a different bandwidth?, your question is not clear, what exactly are you trying to do?

Re: Dual ISP and ECMP

feelgood — Wed, 09 Sep 2020 16:24:50 GMT

Hello @Abdul-Fattah

Here is my configuration actually :

Primary link : FTTO Colt 100Mbits/s
Secondary link : FTTO Colt 100Mbits/s
ECMP enabled with Balanced Round Robin method

Now, here is what I want to set up :

Primary link : FTTO Colt 100Mbits/s
Secondary link : FTTH other ISP 500 Mbits/s
Load balancing (like ECMP active/active method)

I hope it's clearer now.

Thanks.

Re: Dual ISP and ECMP

Abdul-Fattah — Wed, 09 Sep 2020 17:12:20 GMT

I understand now where your misconfusion, EMCP Load balance between routes with same destination and Metric, so when EMCP is enabled the routes with Same destionation and Metric, up to 4 links all will be active.
also in your case, you can use "Weighted Round Robin" as a balancing method and give the new-Link a higher weight
for example:(new-second-Link-weight =5x First-Link), then the traffic-load on the new link will be almost 5 time higher.

Hope that was helpful

Re: Dual ISP and ECMP

feelgood — Thu, 10 Sep 2020 07:50:25 GMT

Hi @Abdul-Fattah

Ok, I understand better now.

So even if my secondary link has twice the bandwidth of my primary link, if I configure the Load Balance method to "Weighted Round Robin" and add my two links as below with the desired size, the traffic will be two times higher on the link configured at 200.

It's ok that both links come from two different ISPs, right ?

Re: Dual ISP and ECMP

Abdul-Fattah — Thu, 10 Sep 2020 07:56:48 GMT

yes and both routes to both ISPs also should have the same metric.

Re: Dual ISP and ECMP

feelgood — Thu, 10 Sep 2020 08:00:35 GMT

Perfect.

Many thanks for your quick help.