[j-nsp] ipv4/ipv6-flow-table-size

Scott Granados scott at granados-llc.net
Mon Aug 25 16:19:31 EDT 2014


That’s about the size of it.

Good luck on your sampling project.  I’ve had pretty good luck with it so far and gotten some great pointers from the list so post away if you have questions.

Thanks
Scott


On Aug 25, 2014, at 4:15 PM, Scott Harvanek <scott.harvanek at login.com> wrote:

> Thanks, I believe this does;
> 
> Assumptions based on this data;
> - I can operate on the defaults for my application [ very little 
> IPv6/VPLS ].
> - I can change it later if needed but that will cause the FPC to reboot.
> 
> -SH
> 
> On 8/25/14, 4:00 PM, Scott Granados wrote:
>> Here’s a bit more that I received that may help clear things up.
>> 
>> 
>> Scott,
>> 
>> A total of 4M flows can be created per 1 LU chip. Now it depends on the size that we allocate to ipv4-flow-table size,ipv6-flow-table-size and vpls-flow-table-size.
>> If only ipv4 template is to be used, then all the memory on the pfe could be reserved only for the ipv4 family.
>> 
>> For eg:  if 15 is allocated for IPv4 then total flows that can be created = 15*256*1024 = 3932160 and 1k IPv6 flows and 1K vpls flows (default).
>> Each unit in flow hash table size corresponds to memory size of 256k (256x1024).
>> 
>> In your case,
>> flow-table-size for ipv4 = 5, Total-flows that can be created = 5*256*1024 = 1310720
>> you are exporting @ 7k flows/sec to the flow-collector
>> If all of your traffic belongs to ipv4: Number of flows getting created = 7*1024*10 = 71680 flows/sec [ 10 = number of flow-records per 1 packet sent to flow-collector ]
>> 
>> 
>> On Aug 25, 2014, at 3:56 PM, Scott Harvanek <scott.harvanek at login.com> wrote:
>> 
>>> Scott,
>>> 
>>> Thanks, my next question then with that is - how/why is the default of
>>> ipv4 15 and ipv6 1?  That would break that constraint of 15 total?
>>> 
>>> Scott H.
>>> Login Inc.
>>> 
>>> On 8/25/14, 3:53 PM, Scott Granados wrote:
>>>> When ever you set the flow table size you initiate a reboot of the FPC.  The table size is a combined value of v4 and v6 so 15 total a subset of which is IPV4 and the remainder is IPV6.
>>>> 
>>>> Thanks
>>>> Scott
>>>> 
>>>> On Aug 25, 2014, at 3:02 PM, Scott Harvanek <scott.harvanek at login.com> wrote:
>>>> 
>>>>> I'm wondering if anyone can clarify something for me from docs:
>>>>> 
>>>>> "
>>>>> 
>>>>>  * Any change in the configured size of flow hash table sizes initiates
>>>>>    an automatic reboot of the FPC.
>>>>>  * The total number of units used for both IPv4 and IPv6 cannot exceed 15.
>>>>> 
>>>>> "
>>>>> 
>>>>> - Does the initial config entry of ipv4/ipv6-flow-table-size cause the
>>>>> FPC to reboot or only if the configured value is changed?
>>>>> 
>>>>> -- I.e. the default for IPv4 size is 15, if that gets changed [ not
>>>>> currently set in config ] does that cause a reboot?
>>>>> 
>>>>> Also, is 15 the maximum aggregate or is it per table:
>>>>> 
>>>>> -- Can you have 15 units assigned to IPv4 and IPv6 at the same time? or,
>>>>> is 15 the maximum between the two?
>>>>> 
>>>>> Thanks!
>>>>> -SH
>>>>> 
>>>>> _______________________________________________
>>>>> juniper-nsp mailing list juniper-nsp at puck.nether.net
>>>>> https://puck.nether.net/mailman/listinfo/juniper-nsp
> 




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