Connecting two gigabit switches to a router

By tim.cappalli ·

Currently I have a setup of:

Netvanta 3448 Router
Netvanta 1325T Gigabit Switch.

I have two cat6 cables connecting the switch to the router using link aggregation. I am now going to add a second gigabit switch, an Asante. How can I connect the two gigabit switches so that a computer on switch 1 can transfer to a computer on switch 2 at gigabit speed with the router in the mix? The router is 10/100. If I connect each switch to the router, I will not be able to achieve gigabit transfers between the computers, correct?

This conversation is currently closed to new comments.

Thread display: Collapse - | Expand +

All Answers

Collapse -

With a 10/100 router in the picture......

by ThumbsUp2 In reply to Connecting two gigabit sw ...

I don't think you'll ever achieve gigabit transfer speeds anywhere. It's the bottleneck.

You might want to have a read here:

Collapse -

Same switch

by tim.cappalli In reply to With a 10/100 router in t ...

Well right now, the computers are achieving gigabit speed. This is due to being on the same switch, correct?

Collapse -

Daisy chain

by tim.cappalli In reply to Same switch

Would I just go from the router, to switch 1 and then switch 1 to switch 2?

Collapse -

Did you read the article?

by ThumbsUp2 In reply to Daisy chain

It specifically says:


Link aggregation is designed to overcome two problems with Ethernet connections: bandwidth limitations and lack of redundancy.

The first issue is that bandwidth requirements do not scale linearly. Ethernet bandwidths historically have increased by an order of magnitude each generation (10 Megabit/s, 100 Mbit/s, 1000 Mbit/s, 10000 Mbit/s). If one started to bump into bandwidth ceilings, then the only option was to move to the next generation which could be cost prohibitive. An alternative solution, introduced by many of the network manufacturers in the early 1990s, is to combine two physical Ethernet links into one logical link via channel bonding. Most of these solutions required manual configuration and identical equipment on both sides of the aggregation.

The second problem is that there are three single point of failures in a typical port-cable-port connection. In either the usual computer-to-switch or in a switch-to-switch configuration, the cable itself or either of the ports the cable is plugged into can fail. Multiple physical connections can be made, but many of the higher level protocols were not designed to failover completely seamlessly.

Furthermore, it says


Single switch

A limitation of link aggregation is that all physical ports in the link aggregation group must reside on the same logical switch which in most scenarios will leave a single point of failure when the physical switch to which both links are connected goes offline.

However, this can be overcome by using vendor-specific extensions which aggregate multiple physical switches into one logical switch. As of 2009, the IEEE has not yet committed resources to standardize this feature.

Collapse -

Yep Thunny that is correct

by OH Smeg Moderator In reply to Did you read the article?

But here the OP asked how to get Gigabite Speeds between the 2 Switches not between the 2 Switches and the Modem.

So the only option possible is to Daisy Chain the Switches so from Switch 1 run a CAT Cable tot he UpLink Port of Switch 2 and then connect the required number of computers.

If they need to keep the same setup the only option is to go to a switch with more ports.


Collapse -

Sorry, but as I read the question......

by ThumbsUp2 In reply to Yep Thunny that is correc ...

The OP said: How can I connect the two gigabit switches so that a computer on switch 1 can transfer to a computer on switch 2 at gigabit speed with the router in the mix? The router is 10/100.

But, I'll defer to you guys, since you know far more about this type of equipment than I do. After all, it was my understanding, based on the old cr@p I've seen, that all communications taking place between computers through any kind of switch had to go up through the router and back down through the switch (or other switches in the picture) because switches don't route, routers do that. And, since I can't find that specific model of switch (Netvanta 1325T) to check the specifications, I assumed it was a dumb switch.

Collapse -


by Jellimonsta In reply to Sorry, but as I read the ...

If the PCs are on the same subnet, there is no routing involved. If he had the switches as separate subnets into different interfaces of the router, then he would need to route. In that scenario there is no way he can do 1Gb with a 10/100 router. :)

Collapse -


by Jellimonsta In reply to Connecting two gigabit sw ...

What are you attempting to get gigabit speeds between? It sounds like you have a work group environment. Do you not have a network/ server environment?
Depending upon how many hosts you have on your network/ work group, will determine if gigabit speeds are truly necessary anyway.
If you want to ensure there is no bottleneck in your LAN due to all systems being 1Gb capable, you will need to create an ether(port) channel trunk for your switch uplinks using multiple interfaces. You will need to consult your switch documentation to see if this is possible.

Related Discussions

Related Forums