How to display maximum throughput of the routing engine on a XOS switch

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We would like to know how much data is going through the routing engine of a BD8800, in other words how much traffic is routed by the switch (the actual maximum we would like to learn) 
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George van Assen

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Posted 3 years ago

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Drew C., Community Manager

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Hi George,
Welcome to The Hub!

If you haven't already, take a look at Pages 5 and 6 of the BlackDiamond 8000 Series Datasheet.  Backplane and slot capacity are listed there, if that is what you're looking for.  There's also some additional capacity information on page 11.  If you are looking for something else, let us know!

-Drew
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George van Assen

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Hello Drew,

Thanks for your reply. Yes, but these are the theoretical numbers.
We would like to know the actual ammount of routed traffic on our blackdiamond, or better yet what is the maximum ammount of routed traffic our blackdiamond has to deal with, the peek moment.

George 
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Drew C., Community Manager

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Hi George,
Can you send me the output of show slot from one of your systems.  The numbers can vary based on chassis model and type of MSM and I/O module.
From that, we'll see what we can get together for you.

Thanks!
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George van Assen

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show sl

[KBD-CR1A.2 # show slot

Slots    Type                 Configured           State       Ports  Flags

-------------------------------------------------------------------------------

Slot-1   G48Tc                G48Tc                Operational   48   M   

Slot-2   G48Tc                G48Tc                Operational   48   M   

Slot-3   G48Tc                G48Tc                Operational   48   M   

Slot-4                                             Empty          0       

Slot-5                                             Empty          0       

Slot-6                                             Empty          0       

Slot-7   10G4Xc               10G4Xc               Operational    4   M   

Slot-8                                             Empty          0       

Slot-9                                             Empty          0       

Slot-10  G48Xc                G48Xc                Operational   48   M   

MSM-A    MSM-48c                                   Operational    0        

MSM-B                                              Empty          0       

 

Flags : M - Backplane link to Master is Active

        B - Backplane link to Backup is also Active

        D - Slot Disabled

        I - Insufficient Power (refer to "show power budget")

BD-CR1A.3 #

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George van Assen

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Hello Drew,

Above the output of the show slot command.. Excuse me for my late reply but had a internet free day yesterday...

George
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Grosjean, Stephane, Employee

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Hi George,

Routing is performed in HW and you can achieved the same throughput in L3 than in L2. Because everything happens in HW, to keep that L3 throughput, you need to stay within the HW capacity of the L3 tables, otherwise slow path (CPU) may happen.

Following the link Drew gave you, you can find all the relevant information.

Looking at the first table of the DS on page 5: You have a BD8810 with c-series modules and a single MSM-48c. You have then a backplane bandwidth capacity of 24Gbps per Slot. You can double that adding a second MSM-48c.

Does it mean the max throughput is 24 * nb_slots? Yes and no. It depends on the traffic pattern and how many L3 entries are considered.

- What about the traffic pattern? I/O module can perform local forwarding, so if your destination is on the same chip, the backplane is not used. Worst case would be every single packet has to go through the backplane.

- What about L3 tables? Simplifying a bit, I/O modules store all the forwarding information in their chip. As long as you stay within their HW capacity, traffic is HW forwarded. But if you put too many entries (too many LPM routes, too many ARP entries, Multicast...) then the chip will not be able to HW forward everything, and the CPU will be used.

You can issue that CLI command to have a view of your L3 resources usage. It's better to execute it during a normal day with a normal activity:

sh iproute reserved-entries statistics

Your limits is listed on the same table of the DS, and this output will also give you the limits. It could be useful to know what EXOS version you're using.

So, assuming you're within the HW capacity, your worst case throughput is 24*5 (slots used) = 120Gbps (or 240Gbps in Marketing math).
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George van Assen

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Thanks for your reply. Again I am not looking for theoretical values of the capacity of this switch.
I am looking for the maximum amount of routed traffic on the switch during normal operation.
Correct me if I am wrong but the "show iproute reserved-entries statistics" is more a summary of the ammount of routes in the route table... 
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Grosjean, Stephane, Employee

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Hi,

The theoretical values can be achieved. But maybe what you want to know is how much traffic is _currently_ routed on your switch?

The "sh ipr reserved stat" command will tell you how many LPM/Hosts/Multicast entries are currently programmed on every slots. This is not the routing table, but really the HW (not a software view, a hardware view).
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George van Assen

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Hello,

Yes, we would like to see "how much traffic is currently routed".....