Port Mirroring SRW2048

Answered Question
Sep 13th, 2009
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Hello,


Does anybody know the specifications about port mirroring funcionality for Cisco SRW2048 48-Port Gigabit Switch?


I need to know about:


1.- Is there any limit in port mirroring sessions?

2.- Can one target port receive traffic from multiple ports?

Correct Answer by Ivor Diedricks about 7 years 6 months ago

Hi Alejandro,


This switch only supports 1 session - i.e. 1 target mirror port. SRW and SFE/SGE switches can have up to 8 source ports while the SLM switches can have up to 4 source ports.In every case there is only one target mirror port.


Thanks,

Ivor

Correct Answer by David Hornstein about 7 years 6 months ago

Hi Alejandro,


I'm not sure what you mean by 'sessions'  , but i'll explain a common sense limit on mirroring a little later.


But for a test, I pulled up my SRW2008P, even though not a SRW2048 and produced the following screen shot at the following community location.


https://www.myciscocommunity.com/message/15201#15201


You can usually mirror both TX and RX traffic from about four ports to a fifth port, even on the SRW2048. But you can, as you wish, limit to only RX traffic from the switches perspective.


In terms of limits to mirrored sessions,  there is a common sense limit .


If the four switch  ports to be mirrored are running at very high port  utilisation  and  you are capturing 3 or  4  switch ports and directing that traffic to a 5th switch port for mirroring purposes, expect packets to be dropped as it egresses out to the mirrored port.  I hope that make sense. You can't have 4Gbits/sec  egressing out a mirrored ports to your PC or capturing utility. :-)


regards Dave

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Alejandro Cadar... Sun, 09/13/2009 - 09:04
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Hi Dave,


Thanks for your answer, of course I understand I can't have 4 Gbps out of the egress port, bust sometimes we know that even when the link is 1 Gbps the traffic is not going to fill that bandwidht.


Regarding the sessions question, I understand by your response you can have:


Source Port    Type                      Target port

g1                           Rxonly                   g3

g2                           Rxonly                   g3

g4                           Rxonly                   g6

g5                           Both                      g6


Can you confirm this?


We are evaluating to propose this switch to a customer and we need to have this feature.


If there isn't any limitation in mirroring traffic, except logical bandwith capabilities, then I can't understand why Catalyst 2960 have a limitation to one or two monitor sessions ... The catalyst are suposed to be better switches ......


Best Regards

David Hornstein Sun, 09/13/2009 - 09:41
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Hi Alejandro,


I am working on a assumption, and i have seen no caveats, that if the management interface allows 4 or 5 switch ports to be mirrored to one switch port, it should work. I must admit I have only used port mirroring for diagnostic purposes, but plenty of people out there use mirroring for UTM  purposes.


I will copy this thread to the SRW product manager for confirmation regarding any caveat.  :)


regards Dave

Correct Answer
Ivor Diedricks Mon, 09/14/2009 - 12:35
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  • Cisco Employee,

Hi Alejandro,


This switch only supports 1 session - i.e. 1 target mirror port. SRW and SFE/SGE switches can have up to 8 source ports while the SLM switches can have up to 4 source ports.In every case there is only one target mirror port.


Thanks,

Ivor

Correct Answer
David Hornstein Sun, 09/13/2009 - 07:33
User Badges:
  • Gold, 750 points or more

Hi Alejandro,


I'm not sure what you mean by 'sessions'  , but i'll explain a common sense limit on mirroring a little later.


But for a test, I pulled up my SRW2008P, even though not a SRW2048 and produced the following screen shot at the following community location.


https://www.myciscocommunity.com/message/15201#15201


You can usually mirror both TX and RX traffic from about four ports to a fifth port, even on the SRW2048. But you can, as you wish, limit to only RX traffic from the switches perspective.


In terms of limits to mirrored sessions,  there is a common sense limit .


If the four switch  ports to be mirrored are running at very high port  utilisation  and  you are capturing 3 or  4  switch ports and directing that traffic to a 5th switch port for mirroring purposes, expect packets to be dropped as it egresses out to the mirrored port.  I hope that make sense. You can't have 4Gbits/sec  egressing out a mirrored ports to your PC or capturing utility. :-)


regards Dave

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