Wired Intelligent Edge

The 8320 Switch has two operation modes. The purpose is to provide the best match in terms of table sizes, depending on the role of the switch.

For example, if the 8320 is acting as an L2 Aggregator (deployed in the aggregation layer with L2 access) it will need large ARP/MAC tables, while when deployed as an L3 Aggregator or Core, it will need larger routing tables and very small ARP/MAC tables.

The mode that works best in the first case is called Mobile First Mode  because it is the most common situation when the 8320 is aggregating L2 access switches and Aruba Mobility controllers.

The mode that fits the second case is called simply Routed Mode and it is the factory default mode of the switch.

Some numbers:

Mode name	Mobile-First	Routed (default)
Forwarding Table Mode Number (CLI)	3	4
L2 entries	98,304	32768
Host entries	120,000	14,000
Route entries	16,384	131,064

The commands to change and display current the forwarding table mode are:

• Change to Mobile First Mode: platform forwarding-table-mode 3

• Return to Router Mode: platform forwarding-table-mode 4

 Notes:

• these commands run in user mode (outside the configure context)
• the system will reboot to operate in a different mode

Example

8320-01# show platform forwarding-table-mode

                               

Mode    L2 Entries    Host Entries   Route Entries

   4         32768           14000          131064

 

8320-01# platform forwarding-table-mode 3

This command requires a reboot to take effect.

 

Do you want to save the current configuration (y/n)? y

<< reboot >>

 

8320-01 login: admin

Password:

 

8320-01# show platform forwarding-table-mode

 

Mode    L2 Entries    Host Entries   Route Entries

   3         98304          120000           16384

 

RUBEN IGLESIAS
Global Consulting TME

Aruba Wired Intelligent Edge

Really interesting and, AFAIK, pretty much undocumented explicitly (at least I'm not able to find any reference on the published ArubaOS-CX Command Line Reference Guide for 10.01): the only reference of "platform modes" on Aruba 8320 platform seems that can be found into the ArubaOS-CX 10.01 Virtual Switching eXtension (VSX) Guide recently published...indeed this statement: "Modes for 8320 series switches: All switches must be either in mode 3 or in mode 4." can be found on that guide...but no info on what those modes mean and how/why to correctly manage them.

Given your precious info about that what is going to be the impact on a Aruba 8320 VSX already running in Platform Mode 4 in case the deployment scenario suggests to switch to Mode 3 instead of staying at default? it will be a matter of just rebooting each node and be prepared for related reboot downtime and nothing more or could be there other issues once both nodes came up again to reform the VSX?

Thanks, Davide.

Hi Davide,

 

Updated documentation covering this feature is coming  soon.  

 

You are correct in that aside from changing the mode on both VSX devices and performing a reboot there should be no other issues to address.

 

One of the lab tests the TME team performed was to take a pair of 10.0 switches, upgrade to 10.1 and then change the forwarding mode to 'mobile first' (mode 3).  In performing this test, we didn't observe any issues with VSX forwarding post-upgrade.

 

 

it will be a matter of just rebooting each node and be prepared for related reboot downtime and nothing more or could be there other issues once both nodes came up again to reform the VSX?

I'll test that tomorrow morning...but, as I wrote, our VSX is not connected to any downstream or upstream peer with any VSX-LAGs so, for me, actually...having "no issues" means that, after the platform mode change and required reboot, I will find the configuration I left (saved) and the VSX reforms flawlessly. Nothing more and nothing less...currently.

I'll report back tomorrow. 

No issues so far, VSX up and running again.

 

Now:

 

Aruba-8320-1# show platform forwarding-table-mode

Mode    L2 Entries    Host Entries   Route Entries
   3         98304          120000           16384

Aruba-8320-1# show platform forwarding-table-mode vsx-peer

Mode    L2 Entries    Host Entries   Route Entries
   3         98304          120000           16384

Good. Thanks.

Hi Davide,

What version of Aruba OS-CX did you have when you changed from forwarding-table-mode 4 to forwarding-table-mode 3?

Regards

Hello Pedro,

Since I did it on August, 8th...both our two Aruba 8320 deployed in VSX were still in a pre-production phase happily running ArubaOS-CX 10.01.0001...just few days after mode change configuration both were then updated to ArubaOS-CX 10.01.0011 (which was released during mid of August) still remaining in staging phase.

Now - in production phase - they are both running latest ArubaOS-CX 10.01.0020.

And they are still showing 98,304 L2 entries when you enter the command: show platform forwarding-table-mode ?

 

To say the truth I didn't check anymore after latest two updates (->0011 and ->0020), I supposed the value you're referring to should not change once the mode (4->3) was set.

Out of curiosity I can check this morning and then report you back.

It is as well 98304 MAC entries for mobile-first mode 3 in 10.01.0030.

I let you guys exchanging on values you see in your live swtiches, that should be what I mention.

I agree with @vincent.giles: I didn't (and I don't) expect that that value changes between ArubaOS-CX updates...at least not before I read it is well documented and highlighted in ArubaOS-CX's Release Notes.

 

I checked:

 

Aruba-8320-1# show version
-----------------------------------------------------------------------------
ArubaOS-CX
(c) Copyright 2017-2018 Hewlett Packard Enterprise Development LP
-----------------------------------------------------------------------------
Version      : TL.10.01.0020
Build Date   : 2018-09-06 11:42:49 PDT
Build ID     : ArubaOS-CX:TL.10.01.0020:f514f45203e2:201809061836
Build SHA    : f514f45203e2bb9284f18b7cd2d6cdce627ab337
Active Image : primary

Service OS Version : TL.01.02.0003
BIOS Version       : TL-01-0013

Aruba-8320-1# show version vsx-peer
-----------------------------------------------------------------------------
ArubaOS-CX
(c) Copyright 2017-2018 Hewlett Packard Enterprise Development LP
-----------------------------------------------------------------------------
Version      : TL.10.01.0020
Build Date   : 2018-09-06 11:42:49 PDT
Build ID     : ArubaOS-CX:TL.10.01.0020:f514f45203e2:201809061836
Build SHA    : f514f45203e2bb9284f18b7cd2d6cdce627ab337
Active Image : secondary

Service OS Version : TL.01.02.0003
BIOS Version       : TL-01-0013

Aruba-8320-1# show platform forwarding-table-mode

Mode    L2 Entries    Host Entries   Route Entries
   3         98304          120000           16384

Aruba-8320-1# show platform forwarding-table-mode vsx-peer

Mode    L2 Entries    Host Entries   Route Entries
   3         98304          120000           16384

As you see, with ArubaOS-CX 10.01.0020, L2 Entries values are clearly still 98304 as they were when Aruba 8320 run on ArubaOS-CX 10.01.0001 (and 0011).

Thanks for your time Davide, I really appreciate your answer.
Have a nice day.

I'm Wondering if the bellow VRD has a typo, 

https://support.hpe.com/hpsc/doc/public/display?docId=a00056448en_us

page 22. 

The 8320 in mobile-first mode => Mac table : 47000 

 

I believe 8320 in Mobile first mode must have a MAC table of 120000 entries, correct me if I m wrong

 

Thanks.

 

Well, first that capability limit (MAC) refers to ArubaOS-CX 10.02 (and that design guide refers to that version since it was published during 2018)...actually IIRC - on ArubaOS-CX 10.03 - the Aruba 8320 operating in L3 Aggregation profile (Mobile First mode) could reach 98304 MACs and 120000 ARPs (but Aruba limited that value to 43000 due to MAC Table Limit - the same is true for ARP due to shared ARP/ND Tables)...so probably they were cautelative speaking about Mobile First mode of operation (which correspond to L3 Aggregation profile).

 

Aruba 8320 in L3 Core (Routed mode) profile thresholds were and are way lower (32768 MACs and 14000 ARPs).

thank you for your quick reply, 

 

getting confused, simply we can say now that 8320 in Mobile first mode, doesn't support 120.000 MAC table entry right ? 

 

I'm asking these questions simply because I have to design a mobility aggregation layer where I have to connect 6x 72xx controllers. and I have a campus of more than 100.000 devices. 

8320 with mobile-first mode will work? 

 

- Will 8320 perform L3 function (ie: being default-gateway) ?

- IPv4 only or dual-stack IPv4 and IPv6 ?

- yes, 8320 will be the default gateway for the wireless agg layer 

- IPv4 only 

On 8320/8325 we support 120000 ARP but that maximum number comes with multiple IP behind the same MAC.

For 1:1 binding, then the limit is 43000 for 8320 and 47000 for 8325.

 

Do you have 100000 simultaneous devices ?

If so, you would need at least 2x 8320 pairs or better 3 pairs.

The attachment of the controllers could be:

- split of the cluster into 3 parts, each attached to a VSX pair of 8320: this will imply hard roaming.

- or keep all mobility controller into same mobility cluster but attach each mobility controller to each 8320 VSX pair (you would need 6 links per mobility controller). Roaming capacity is maintained.

that answered my question, 

basically, I'll have 2x8320 with VSX.

I prefer to go with 1 cluster and attach each MC to my 2x8320 via 10G links. 

 

regarding the question, I don't think I'll have 100000 simultaneous devices, 

ok. I would suggest to know how many simultaneous MAC/clients.

With more than 43k, there will be potential collisions in the ASIC.

Hi! How these possible routed and mobile first modes influence system troughput in each of them?

------------------------------
Igor Grishchenko
------------------------------

Original Message:
Sent: Nov 18, 2019 05:04 PM
From: Vincent Giles
Subject: 8320 Switch: Forwarding Table Modes

ok. I would suggest to know how many simultaneous MAC/clients.

With more than 43k, there will be potential collisions in the ASIC.

Hi Igor,

As mentioned , ASIC processed traffic is not impacted if the number of ARP/ND, MACs, routes stay within the profile limits. If limits are exceeded,
traffic may be dropped.

There are 4 ASIC profiles depending on usage (actually mainly 2: agg or core):
8320-3# sh profiles available

Available profiles
-------------------
L3-agg 98304 L2 entries 120000 Host entries 16384 Route entries
L3-core 32768 L2 entries 14000 Host entries 163796 Route entries
(Default)
Leaf 98304 L2 entries 120000 Host entries 16384 Route entries
Spine 32768 L2 entries 14000 Host entries 163796 Route entries


Depending if the switch is positioned for aggregation (maximizing ARP and MAC) or core (maximizing routes).

------------------------------
Vincent Giles
------------------------------

Original Message:
Sent: Feb 01, 2021 06:12 AM
From: Igor Grishchenko
Subject: 8320 Switch: Forwarding Table Modes

Hi! How these possible routed and mobile first modes influence system troughput in each of them?

------------------------------
Igor Grishchenko

Original Message:
Sent: Nov 18, 2019 05:04 PM
From: Vincent Giles
Subject: 8320 Switch: Forwarding Table Modes

ok. I would suggest to know how many simultaneous MAC/clients.

With more than 43k, there will be potential collisions in the ASIC.