HSRP Limit on Cisco Nexus 9K

[jduty]

Our two core switches are Cisco Nexus9000 93180YC-EX chassis. They are both running a somewhat older version of NXOS version 7.0(3)I7(6). 

We use HSRP version 2 between the two of them and are in the works of introducing several hundred SVIs to them but wanted to verify what the number limit is on SVIs on this particular model running that version of NXOS while having HSRP enabled for each of the interfaces. I have found several documents that seem to have conflicting information on it, though I am sure I am missing something that justifies the different limit. The limit appears to be related to the amount of Virtual MAC Addresses supported, which HSRP uses for the active member. 

Does anyone know of a specific Cisco site that helps make finding limitations of their switches and features on them a bit easier than just trying to find random articles online? 

[balaji.bandi]

SVI and Limited to upto extended VLAN support, same case with HSRPv2 give you option 0 to 4095 numbers , so that is the limit.

check below help you in related to nexus :

https://www.cisco.com/c/en/us/td/docs/switches/datacenter/nexus9000/sw/6-x/unicast/configuration/guide/l3_cli_nxos/l3_hsrp.html

[MHM Cisco World]

there is HSRP v2 limit which is 0-4095 number (4096)
and there is SVI limit 
I think your confuse is 
are all HSRP group have SVI ? Yes 
are all SVI have HSRP group ? No, you can config it and you can not 

so for SVI that have HSRP group you can up to 4096 SVI 
for SVI have and have not HSRP this depend on virtual MAC address. BUT 
still there is protocol which limit your number of VLAN (SVI) to 4096 (you see it same as HSRP group limit number)
if you need more than SVI then you can go to VXLAN which design for this case. 
https://www.nakivo.com/blog/vxlan-vmware-basics/

[jduty]

Thanks for the input, however, in CML (Cisco Modeling Labs), I am getting an error after configuring 900 vlans with an SVI with HSRP enabled stating that there could be no more Virtual MAC addresses created to support the SVI since I hit the 490 limit. I guess the only other answer is that this could be a limitation of CML? 

Here is the document I was referencing that says 490 vs 1000 hsrp instances. (Cisco Nexus 9000 Series NX-OS Verified Scalability Guide, Release 9.2(3) - Cisco ) 

[balaji.bandi]

Virtuals are different (especially CML) compare to real hardware device we referring.

Always Lab image do not get the features offered by Physical real device.

[MHM Cisco World]

that exactly what I mention above 
you have two SVI 
with and without HSRP 
and the SVI is limit by 
1- Virtual MAC (TCAM and HW resource different in each NSK platform)
2- protocol 
A- ethernet protocol accept tag of vlan for max. 4096
B- VXLAN protocol accept more than 4096.

for CML sure this is limit. you can not depend on it 100%, I surprise that it accept until 900 SVI. 

[jduty]

Sure thing. I understand that you can have an SVI without it being in an HSRP group. In our case, all our SVIs have their own group number. Maybe I should add that it isn't the amount of HSRP groups that are in question and how the HSRP Group is associated with the SVI, but rather, it is how many HSRP instances can be run on these switches. (i.e. if I have 900 VLANs and I wanted each of them to have their own HSRP instance, is that possible. Hopefully that helps to clarify my angle.) 

The link I posted says there is a limit of 1000 SVIs with HSRP enabled, but thats for NXOS 9.2(3), so I'm not sure how you can still can more than that (the 4096) when Cisco's documentation "clearly" states that 1000 is the limit.

In addition to that, we are not running that version of NXOS on our cores, so is there a way to see if the limit is lower on a switch running NSOS 7.0(3)I7(6)?

[Andrea Testino · Accepted solution]

Hi there,

I believe you are looking for the Verified Scalability Guide for NXOS 7.0(3)I7(6) which states how many HSRP Groups can be instantiated on a given switch. 

Look under Table 13. Unicast Routing Verified Scalability Limits:

Hope that helps.

[jduty]

Ahh,, yes!!!  this is exactly what I was looking for, just couldn't find it for the different OS releases. I wanted some hard evidence or hard facts from Cisco documentation that said that.  Thank you so much!