SFP vs LACP in mixed switch environment

[Agnon Amouse]

Hello all, this is my first post. I am getting back into networking after quite a while away from the game so go easy on me.

Our environment has 3 switches, Our core is a cisco SG-500-28p, the others are an HP v1910-48G, and a linksys SRW2024p.

I want to know the best way to connect these switches for redundancy and speed if possible. I realize that may be 2 different answers.

I will also need to know if spanning tree protocol will need to be used vs LACP ect for the best solution because I am very new to using those.

I am attaching a document to show some examples but they will basically be variations using the SFP ports or standard ports. Again these may not even make sense so go easy on me please.

The srw2024 has 2, 1 gigabit SFP ports

The sg500-28p has 4, 10gig SFP ports

The V1910-48G has 4, 1gig SFP ports

I am only assuming here but I believe the speed can be set or will auto negotiate down on the SG500 SFP ports

Would there be an advantage to using the SFP ports vs a pair of standard aggregated LACP ports? Both the SFP and standard ports are 1 gigabit.

Take a look at my crude drawings, please show me what I missed and what I clearly do not understand so that I can make this work.

[Agnon Amouse]

Here is another one that I found that may make more sense.

Would I need STP enabled on all 3 switches and the root bridge set to the core switch or just STP enabled on the core?

I would use LACP to aggregate the ports for interconnection between switches

[Joseph W. Doherty]

Disclaimer

The Author of this posting offers the information contained within this posting without consideration and with the reader's understanding that there's no implied or expressed suitability or fitness for any purpose. Information provided is for informational purposes only and should not be construed as rendering professional advice of any kind. Usage of this posting's information is solely at reader's own risk.

Liability Disclaimer

In no event shall Author be liable for any damages wha2tsoever (including, without limitation, damages for loss of use, data or profit) arising out of the use or inability to use the posting's information even if Author has been advised of the possibility of such damage.

Posting

Yes, that design will work, but do you need the additional bandwidth, and are your SFP ports "better" than your copper ports.  (Again, sometimes they are, as the switch might be design to support a heavier traffic load on them.)

PS:

You need STP on all 3 switches when you loop them.

[Agnon Amouse]

Thank you, If RSTP is available on all 3 switches would you recommend that or mstp?

[Agnon Amouse]

I should also add that I am not utilizing multiple VLANS, Everything is running on the default Vlan. Not sure if that matters or not.

[Joseph W. Doherty]

Disclaimer

The Author of this posting offers the information contained within this posting without consideration and with the reader's understanding that there's no implied or expressed suitability or fitness for any purpose. Information provided is for informational purposes only and should not be construed as rendering professional advice of any kind. Usage of this posting's information is solely at reader's own risk.

Liability Disclaimer

In no event shall Author be liable for any damages wha2tsoever (including, without limitation, damages for loss of use, data or profit) arising out of the use or inability to use the posting's information even if Author has been advised of the possibility of such damage.

Posting

Yes it matters.  For just one network RSTP will be fine.

[Agnon Amouse]

Thanks so much for taking the time to help me learn this. I know I have a long way to go but you have been a great help.

I want to go over this really quick one time to see if this is what I need. I will be using the last ring\triangle configuration with the Cisco sg500 in L3 mode set as the Root bridge with RSTP enabled.

I would need a 2 LACP groups on this switch: 1 LACP group (2 ports) to the Linksys  and 1 LACP group (2 ports) to the HP as another group.

On the HP I would need 2 LACP groups: 1 LACP group (2 ports) to the Cisco and 1 LACP group (2 ports) to the Linksys. RSTP would need to be enabled, Protection type would be Loop? If not then what would the protection type need to be.

For the Linksys 2 LACP groups as well: 1 LACP group (2 ports) to the HP and 1 LACP group (2 ports) to the Cisco. Rstp Enabled, same protection type as the HP?

Will each switch just use 1 RSTP instance or would I need 2 for each switch?

Does that sound right and if not would you be willing to fill in the blanks for me or point me in the right direction.

Thanks again!

[Joseph W. Doherty]

Disclaimer

The Author of this posting offers the information contained within this posting without consideration and with the reader's understanding that there's no implied or expressed suitability or fitness for any purpose. Information provided is for informational purposes only and should not be construed as rendering professional advice of any kind. Usage of this posting's information is solely at reader's own risk.

Liability Disclaimer

In no event shall Author be liable for any damages wha2tsoever (including, without limitation, damages for loss of use, data or profit) arising out of the use or inability to use the posting's information even if Author has been advised of the possibility of such damage.

Posting

Ah, I forgot you're using a non-Cisco switches and also Cisco non-catalyst switches too.  Where this can matter,s on Cisco Catalyst switches, of which I'm familar, they support per-VLAN RSTP.  If the other switches don't, there might be an inter-operational issue, but perhaps not, as you're only using one VLAN.  If there is an issue, then you might need to use MST.

I'm also unaware of "loop" protection - something found on HP?  Unfortunately I'm unable to advise you much on non-Cisco switches or even Cisco SMB switches.

Regarding LACP, two groups per switch sounds correct, with a group for each bundle to a different switch neighbor.

[Joseph W. Doherty · Accepted solution]

Disclaimer

The Author of this posting offers the information contained within this posting without consideration and with the reader's understanding that there's no implied or expressed suitability or fitness for any purpose. Information provided is for informational purposes only and should not be construed as rendering professional advice of any kind. Usage of this posting's information is solely at reader's own risk.

Liability Disclaimer

In no event shall Author be liable for any damages wha2tsoever (including, without limitation, damages for loss of use, data or profit) arising out of the use or inability to use the posting's information even if Author has been advised of the possibility of such damage.

Posting

Optical links have a few advantages over copper links, and sometimes an SFP port will have advantages over a copper port.  Gig copper will transmit as quickly as gig fiber (as they are both rated at gig).  SPF modules do add to your cost.

Personally, unless I need optical features (usually for distance) or unless the a SFP port is actually better than a copper port, I'll use copper for inter switch links too.  (BTW, there's also copper SFPs.)

For redundancy, you'll want to loop your switches.  When you do, you'll need some variant of STP (which should be enabled all the time as a safeguard).

LACP might be used to increase aggregate bandwidth between devices.  You can run into issues on how you load balance traffic across a LACP bundle.  LACP also provides link redundancy between devices, but if the switch itself fails, you'll need a ring to guarantee the remaining two devices remain connected.

BTW, in your 2nd design, LACP only works for multiple links between the same two devices.  I.e. what you propose won't work.

Designs 1 and 4 don't require STP, but again, it should be enabled anyway.