3064PQ Port mirror performance

[blackmetal]

Hello,

We have an N3K-C3064PQ-10GX with ~12g bps and 5m pps with 2x 10G LACP from our ip transit, we want to connect a server with 2x 10g to this 3064pq for traffic analyzing and mirror uplink port-channel to this server,

so i want to know port mirror this amount of data from one port-channel to another port-channel impact on CPU or cause any CPU issues?

Thank you.

[blackmetal]

any update on this topic?

[Christopher Hart]

Hello!

On Nexus switches, replication of packets from SPAN monitor sessions are performed in hardware. Therefore, there will be no impact on the control plane CPU of the switch when a SPAN monitor session is active.

You can use the Ethanalyzer control plane packet capture tool to confirm that no data plane traffic replicated by a SPAN monitor session can be observed by the control plane of the switch.

I hope this helps - thank you!

-Christopher

[blackmetal]

@Christopher Hart 

as i read https://www.cisco.com/c/en/us/td/docs/switches/datacenter/nexus3000/sw/system_mgmt/503_u2_2/Cisco_Nexus_3000_system_mgmt_config_gd_503_U2_2_chapter13.pdf it seems there are some limitation for monitor session and it seems it can not monitor more than 6gbps is it correct?

i have around 9gbps bps and i want to mirror it to another port, can this traffic mirror completly ?

also is it posible mirror a port-channel to another one ?

i am using n3k-c3064pq-10gx

[Christopher Hart]

Hello!

It sounds like you are referring to the following limitation:

"If the SPAN source interface sends more than 6-Gbps traffic or if traffic bursts too much, the device drops traffic on the source interface. You can use the switchport monitor rate-limit 1G command on the SPAN destination to reduce the dropping of actual traffic on the source interface; however, SPAN traffic is restricted to 1 Gbps."

Based on that limitation, you will not be able to replicate all 9Gbps of your data plane traffic without dropping some data plane traffic.

Port-channels are not supported as SPAN destination ports - see the "Characteristics of Destination Ports" section of the Cisco Nexus 3000 Series NX-OS System Management Configuration Guide.

Thank you!

-Christopher

[blackmetal]

i am really curious why does this limitation available? this switch can handle 1tbps bps but for span we can have 6gbps only?