MX Traffic Shaping Priority

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HovnanianEA
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MX Traffic Shaping Priority

Hi All. Quick question regarding traffic shaping priority. When default traffic shaping rules are enabled, do these rules apply first before a custom traffic shaping rule is created even as a high priority?

 

We would like to send all VoIP and Video Conferencing as EF but if default rules are being applied first, the Webex/Skype/Teams traffic may be sending AF41 instead.

1 Accepted Solution

That's not what he is asking. He is asking about the Shaping Rules. https://documentation.meraki.com/MX/Firewall_and_Traffic_Shaping/SD-WAN_and_Traffic_Shaping

 

Confirmed.  Custom rules are preceding the default ruleset. 

 

Testing done with Teams ( 52.0.0.0/8 ) 

 

RaphaelL_0-1675182771316.png

 

All my trafic to Teams was remarked with the marking CS1 and not EF or AF41 from the default rule :

 

RaphaelL_1-1675182839224.png

 

 

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7 Replies 7
alemabrahao
Kind of a big deal
Kind of a big deal

 

Traffic Queues

Specifying a traffic shaping rule as High, Normal, Low guarantees a certain fraction of the uplink to each priority level. The ratios are as follows:

  • High       4/7
  • Normal   2/7
  • Low       1/7

Full doc here: https://documentation.meraki.com/MX/Firewall_and_Traffic_Shaping/Using_Packet_Prioritization_on_a_Tr...

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

I'm not 100% sure , but I think that the MX will process the custom rules before the default rules. I'm trying to confirm with a PCAP. 

 

By default, all traffic is marked as having a Normal priority level. Traffic shaping rules that are marked at the same priority level share the same fraction of their respective levels. For instance, if there are 5 traffic shaping rules marked as High priority on a 10Mbps pipe each rule would have access to ~1.1Mbps.

 

Each traffic rule supersedes each rule below it and the rules below it must strictly adhere to their fractional bandwidth limits. For instance, if there is a high traffic shaping rule but no low traffic shaping rules configured then the high priority traffic would have access to 5/7 of the available bandwidth on the uplink and normal traffic would have 2/7s. Additionally, if there are no high priority traffic shaping rules then normal priority traffic gets 6/7 of the bandwidth and low priority gets 1/7 of the uplink's bandwidth.

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.

That's not what he is asking. He is asking about the Shaping Rules. https://documentation.meraki.com/MX/Firewall_and_Traffic_Shaping/SD-WAN_and_Traffic_Shaping

 

Confirmed.  Custom rules are preceding the default ruleset. 

 

Testing done with Teams ( 52.0.0.0/8 ) 

 

RaphaelL_0-1675182771316.png

 

All my trafic to Teams was remarked with the marking CS1 and not EF or AF41 from the default rule :

 

RaphaelL_1-1675182839224.png

 

 

This informations is about shaping. 😉

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.

Basically what the text informs is that when I create a rule specifying the priority as High it will have a higher priority than the default rule, that is, what will come into effect is the DSCP configured in the rule marked as High and not what is defined by default, but that's ok, the important thing is that the doubt was clarified and everyone is so happy. 😀

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.

Thank you very much!

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