SD-WAN Custom performance classes

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guitb
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SD-WAN Custom performance classes

Hi everyone,

 

I'm trying to set up a custom performance class in Meraki SD-WAN and I'd like some clarification on the failover logic.

If I create a class with the following thresholds:

  • Latency: >100ms

  • Packet Loss: >5%

Will the traffic fail over to the secondary WAN link if either of these conditions are met, or do both conditions need to be exceeded at the same time to trigger the failover?

 

 

1 Accepted Solution
RaphaelL
Kind of a big deal
Kind of a big deal

Just did some hardcore testing. 

 

RaphaelL_6-1755267305431.pngRaphaelL_7-1755267333591.png

 

No failover as expected. WAN1 and WAN2 have less than 10ms latency and 0% loss.

 

Now , I have plugged a RPI in WAN2 , bridged the interfaces , added 100ms latency with tc.

RaphaelL_9-1755267563539.png

 

 

RaphaelL_8-1755267468556.png

 

Only met the first critieria of the Test custom performance class and the traffic did failover to WAN1.

 

 

TL;DR I was wrong, but nothing beats a real world test to prove me wrong !

 

 

 

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6 Replies 6
alemabrahao
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Kind of a big deal

The failover logic is triggered if any one of the conditions is met, not necessarily all at once.

 

Meraki SD-WAN

 

Meraki SD-WAN - Cisco Meraki Documentation

I am not a Cisco Meraki employee. My suggestions are based on documentation of Meraki best practices and day-to-day experience.

Please, if this post was useful, leave your kudos and mark it as solved.
RaphaelL
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Kind of a big deal

Hi ,

 

Both conditions need to be exceeded at the same time to trigger the failover. 

 

https://documentation.meraki.com/MX/Firewall_and_Traffic_Shaping/MX_Load_Balancing_and_Flow_Preferen...

Performance classes can also be created to define a minimum performance standard. If these standards are not met, traffic will be routed through the alternative uplink.

 

Unless I'm mistaken that's how I understood the documentation

 

 

EDIT: I was wrong. See below.

alemabrahao
Kind of a big deal
Kind of a big deal

I already have a different understanding than yours based on this other document.

"This rule will evaluate the packet loss of established VPN tunnels and send flows matching the traffic filter out of the preferred uplink. If the loss, latency, or jitter thresholds in the "Web" performance rule are exceeded, traffic can fail over to tunnels on WAN2 (assuming they meet the configured performance criteria)."

 

https://documentation.meraki.com/Architectures_and_Best_Practices/Cisco_Meraki_Best_Practice_Design/...

I am not a Cisco Meraki employee. My suggestions are based on documentation of Meraki best practices and day-to-day experience.

Please, if this post was useful, leave your kudos and mark it as solved.
RaphaelL
Kind of a big deal
Kind of a big deal

Just did some hardcore testing. 

 

RaphaelL_6-1755267305431.pngRaphaelL_7-1755267333591.png

 

No failover as expected. WAN1 and WAN2 have less than 10ms latency and 0% loss.

 

Now , I have plugged a RPI in WAN2 , bridged the interfaces , added 100ms latency with tc.

RaphaelL_9-1755267563539.png

 

 

RaphaelL_8-1755267468556.png

 

Only met the first critieria of the Test custom performance class and the traffic did failover to WAN1.

 

 

TL;DR I was wrong, but nothing beats a real world test to prove me wrong !

 

 

 

PhilipDAth
Kind of a big deal
Kind of a big deal

I wish I could give you double-double kudos for going the extra mile.

RaphaelL
Kind of a big deal
Kind of a big deal

The real extra mile will be to request a documentation clarification😅

 

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