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LioElectronicFlag for Australia

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LAG between Dell Switches

Hi there,

I have 5 Dell Switches that I would like to connect them together.

My idea is to use Swcith1 as the main central switch where Switch2, 3, 4 and 5 will be plugged into.

On Switch1 I want to create LAG to increase bandwidth for the uplinks coming from the other switches. I am thinking to setup 2 ports (LAG) for each switch.

Something like this:

Switch1 - Port1-2 = LAG2 --> Uplink --> Swtich2 - Port 1-2 = LAG2
Switch1 - Port3-4 = LAG3 --> Uplink --> Swtich3 - Port 1-2 = LAG3
Switch1 - Port5-6 = LAG4 --> Uplink --> Swtich4 - Port 1-2 = LAG4
Switch1 - Port7-8 = LAG5 --> Uplink --> Swtich5 - Port 1-2 = LAG5

Is this good configuration? Would be any loop or performance issues on the network ?

Avatar of Rick_O_Shay
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I don't know Dell configs but that looks good.
When configuring LAGs the system looks at the pair of links as one relative to spannning tree so there shouldn't be any loops.
Avatar of Sebastian Talmon
yes, this config looks good for Dell switches.

do you plan to attach servers also with LAG?

note that LAG route packets with a policy based on hashing mac/IP (depending of your config), and connections between two devices with the same hash value are limited to 1 Gbit - you have only a performance gain for traffic between different devices.
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Hi Tacotec,

Im not planning to attach servers with LAG. My goal is to increase bandwidth between the switches and avoid bottlenecks.

Avatar of skullnobrains

This setup looks workable.

Then I cannot tell if it fits your needs so I cannot determine wether it is good.

What I can tell you is that it is not a redundant setup. If switch 1 dies, the network dies

A round setup with spanning tree may be another reasonable choice but again we cannot answer or advice without knowing your requirements
Hi skullnobrains,

My goal is to improve bandwidth between the switches.  The redundancy is a problem. Due budge I cannot have a second central switch.
Would you suggest any other configuration for redundancy ?
Avatar of Sebastian Talmon
Sebastian Talmon
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Hi Tacotec,

Im using Dell Switches. It is a bit of mix between. They are not the basic entry level but not the top ones. The central switch is not a bad one (cost us $2000.00).

The switches today are connected in "tree topology" which in my option is not the best option.

I wish I could have at least one 10Gb port in each switch to connect them but it is not an option. That is why I trying to connect them with at least 2x 1Gb link to avoid too much bottleneck.
6224 for the Central switch, and 5548 for the others?

I have 7200 series as the central switch and 5300 and 2800 among the others
the "round setup" would be a ring of switches. not that difficult to setup, rather redundant, but less performant in some cases because some traffic will have to go through several switches to reach destination (but not worse with 5 switches since in your setup, most of the traffic will go through 3 switches to reach destination anyway)

don't you have enough ports to have 2 central switches for redundancy ?
enough to use double attachments on the machines ? is that what you plan ?
are the switches stackable ?
do you have an existing firewall or router that can cope with more load and hence take part of the role of the central switch ? in that case you may not even need a central switch at all ?

if you elaborate on the topology : existing hardware, number of machines, number of zones/vlans, needed throughput inside and between zones, maybe we can come up with something better.