How to do a ELAM capture on Catalyst and Nexus switches

[krunal_shah]

Anyone familier with ELAM captures it capture the packets at the ASIC level. Very helpfull in trobleshooting I could not find and cisco document that explains how to do that. Can anyone share this info?

[vvasisth · Accepted solution]

“show platform capture elam…” keyword is used to configure capture sessions…

Router# show platform capture elam asic  [superman | tycho] [slot slot_n] [processor proc_n]          [instance inst_n]

Router# show platform capture elam trigger

  {{dbus [ipv4 ipv6 ipx others inband]} | {rbus [ip gen extip extgen]} | {de} }[  [if trigger] | help ]

Router# show platform capture elam start

Router# show platform capture elam status

Router# show platform capture elam release

…and the same keyword is used to display captured data

Router# show platform capture elam data [raw]

Just in case, if you don’t remember how to use these commands:

Router# show platform capture elam help

Hope this helps

Varun

[krunal_shah]

Your reply is really helpfull but following command has every explanation.

C6506C#show platform capture elam help
To make ELAM working for you, here the basic steps you've to follow:
1 - select a valid ELAM ASIC
    cmd:     show platform capture elam asic
    example: ...asic superman slot 5
             - select the Superman ASIC on slot 5
2 - enter a valid trigger
    cmd:     show platform capture elam trigger
    example: ...trigger dbus ipv4 if ip_da=224.1.0.0[255.255.0.0]
             - capture any IPv4 packet with DESTIP == 224.1.0.0/16
             ...trigger rbus ip if ccc=mcast_l3_rw met3=0x0300[0xff00]
             - capture any IP packet generating a ML3_RW result with
               MET3 pointer equal to 3xx
             ...trigger dbus help
             - return an extensive list of dbus field you can use
3 - start the capture
    cmd:     show platform capture elam start
4 - check the capture status
    cmd:     show platform capture elam status
5 - print the captured data
    cmd:     show platform capture elam data
simple enough, isn't it ?

[Bedevere Curry]

Thanks. Very useful and I love the example.

[Bedevere Curry]

I have nexus 5596 running version 5.1(3)

I'm trying to troubleshoot an issue and wanted to know if I can capture at the asic level.

I don't seem to have "show platform capture" option. Does anyone know the command to accomplish this task?

Thanks

[Raymond Kraft]

Bedevere,

ELAM is not supported on N5k.

-Ray

[Bedevere Curry]

Thanks

[zdrechsl]

Hello,

I see you'd like guidance on ELAM captures for Nexus switches. Here is a video a colleague of mine made on ELAM captures for Nexus 9000 devices. Hope this is helpful!

https://youtu.be/s0PSHN2Qxhc