Use Core Switch as an L2 Access Switch

herbey zepeda

7/27/23, 3:17 PM

Can I use a CORE switch as an ACCESS Layer 2 switch? The end goal is to connect all servers through at least a 10Gb network. The servers each have high volumes of data that will be transferring back and forth to and from each other. Slower networks and internet access are not in the picture. The data transfer is strictly between the servers that would be connected to the CORE switch. Each of the motherboards in said servers will have a 10Gb card connected to the PCIe slot. I have a managed 3500 series Cisco switch that only has 4 10Gb uplink ports and the rest are 1Gb. I think I might have purchased this switch due to my lack of knowledge and requirements. The 1Gb ports are not useful for y use case. I would like ALL ports to be as fast as possible. In fact, if I can go beyond the 10Gb mark, I would (40Gb/s, 100Gb/s, etc...) but for simplicity and in order to move one baby step at a time, I would like to know if I can hookup my servers to a CORE switch with all SFP+ 10Gb/s ports as indicated in the diagram. Thanks

EDIT Thanks for the comments...I think I will stop at 10Gb/s if my goal is to move the data from Motherboard-1 to the RAM in Motherboard-2 as SATA 3 does not go beyond 6Gb/s and the real bottleneck is in HDD/SSD anyway so it would make no sense to invest in higher than 10Gb/s.

Image

0 + 0

networking

switch

10gbethernet

vidarlo

7/27/23, 3:25 PM

Why would this *not* work?

joeqwerty

7/27/23, 3:32 PM

You can hook them up to any switch you like. Don't get hung up on hierarchical network models. They are suggestions and recommendations, not rules set in stone.

Score:1

Server

Tilman Schmidt

7/27/23, 6:21 PM

The labels "core switch" and "access switch" which some vendors put on certain switch models are just suggestions for where in your network architecture they might be most useful. There is no technical reason against connecting servers or even clients directly to an all 10G switch even if it is sold as a "core switch". Nor is there a technical reason against using a switch sold as an "access switch" in a core switch position if it satisfies your bandwidth needs.

0 + 0

herbey zepeda

7/27/23, 8:50 PM

Thanks, I think that for my purposes, 1GB should be more than enough. If my goal is to load to Motherboard-2's RAM a high volume of data coming from Motherboard-1, seems like the bottleneck is the storage, especially when the storage is HDD. At this point I am trying to decide whether a separate NAS and compute are the answer or whether the same motherboard should act as both NAS and compute. Seems that it all boils down to whether the additional network latency is acceptable:

herbey zepeda

7/27/23, 8:56 PM

I meant 10Gb/s ^^

Elon Musk

I sit in a Tesla and translated this thread with Ai:

EN: Use Core Switch as an L2 Access Switch

TH: ใช้ Core Switch เป็น L2 Access Switch

RO: Utilizați Core Switch ca comutator de acces L2

RU: Используйте основной коммутатор в качестве коммутатора доступа L2

VI: Sử dụng Core Switch làm Switch truy cập L2

Post an answer

Most people don’t grasp that asking a lot of questions unlocks learning and improves interpersonal bonding. In Alison’s studies, for example, though people could accurately recall how many questions had been asked in their conversations, they didn’t intuit the link between questions and liking. Across four studies, in which participants were engaged in conversations themselves or read transcripts of others’ conversations, people tended not to realize that question asking would influence—or had influenced—the level of amity between the conversationalists.