Wired Intelligent Edge (Campus Switching and Routing)

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Aruba Employee

8320 Switch: Forwarding Table Modes

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 Modeplatform 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

Ruben Iglesias
Regular Contributor II

Re: 8320 Switch: Forwarding Table Modes

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.
Occasional Contributor I

Re: 8320 Switch: Forwarding Table Modes

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?

Regular Contributor II

Re: 8320 Switch: Forwarding Table Modes

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. 

Regular Contributor II

Re: 8320 Switch: Forwarding Table Modes

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.

Frequent Contributor I

Re: 8320 Switch: Forwarding Table Modes

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

 

Pedro

PS: If you feel this information is useful and solved your question or problem, please do not forget to mark it as a solution and give me some kudos.
Regular Contributor II

Re: 8320 Switch: Forwarding Table Modes

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.
Frequent Contributor I

Re: 8320 Switch: Forwarding Table Modes

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

 

Pedro

PS: If you feel this information is useful and solved your question or problem, please do not forget to mark it as a solution and give me some kudos.
Regular Contributor II

Re: 8320 Switch: Forwarding Table Modes

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.
Aruba Employee

Re: 8320 Switch: Forwarding Table Modes

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.

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