Go Premium for a chance to win a PS4. Enter to Win

x
?
Solved

Teaming (LAG) swtich ports across non-stacked switches

Posted on 2008-06-19
14
Medium Priority
?
4,126 Views
Last Modified: 2008-06-21
Is it possible to LAG or Team switch ports across switches that are not stacked or even stackable?  I say no, that it's not possible even using LACP, but I have a client that believes that it is possible.  

The specific switches in question are the Dell 5424 (a L2 managed switch).  Tech specs link here:
http://www.dell.com/content/products/productdetails.aspx/pwcnt_5424?c=us&cs=04&l=en&s=bsd
0
Comment
Question by:pwyzorski
  • 7
  • 4
  • 3
14 Comments
 
LVL 13

Assisted Solution

by:kdearing
kdearing earned 300 total points
ID: 21827088
Yes, you can.

You can use it to increase bandwidth between 2 devices, or to connect to redundant switches, etc.
0
 

Author Comment

by:pwyzorski
ID: 21827706
Yes, I understand the utility of Link Aggregation well enough.

My question was more to the point of how to setup Link Aggregation across non-aggregate switches.  What is the protocol that determines what port on which switch gets used for downlink traffic.  Is it LACP? Static or Dynamic mode?

The protocol to determine which uplink port on aggregate NICs to use for upstream traffic from the host is simple enough to understand.  It's the downlink trip from the network back to the host that confuses me.

I think that the LACP protocol is used to determine a dynamic route and downlink port downstream to the host even across non-aggregate switches. But can LACP be used in static mode to determine a route across non-aggregate switches.
0
 
LVL 13

Assisted Solution

by:kdearing
kdearing earned 300 total points
ID: 21828364
Enen though 802.3ad is supposed to be a standard, many maunfacturers have implemented their own flavor with 'enhancements' (especially Cisco).

I've set up some Nortel switches and they have a 802.3ad extension called Split Multi Link Trunking.
This allows two aggregation switches to appear as a single device to edge switches that are dual homed to the aggregation switches.

I'm not sure if those specific Dell switches have similar capabilities.
0
[Webinar] Cloud and Mobile-First Strategy

Maybe you’ve fully adopted the cloud since the beginning. Or maybe you started with on-prem resources but are pursuing a “cloud and mobile first” strategy. Getting to that end state has its challenges. Discover how to build out a 100% cloud and mobile IT strategy in this webinar.

 
LVL 21

Accepted Solution

by:
from_exp earned 1200 total points
ID: 21828560
hi!
Teaming can have different types of behavior: aggregated and redundant.
when the first one is generic link aggregation based on 802.3ad, the second use the second card only when the first one fails.

as for switches I haven't seen switches save Nortels where it is possible to use aggregated mode in non-stacked configuration. however it is always possible to use redundant mode with non-stacked switches, where from the switches' perspective you have only two normal ports going to the same server.
0
 

Author Comment

by:pwyzorski
ID: 21828649
I read about SMLT in Nortel switches, but that isn't what I have.  I'm more curious about how it's supposed to work in a general sense.
0
 

Author Comment

by:pwyzorski
ID: 21828659
"however it is always possible to use redundant mode with non-stacked switches, where from the switches' perspective you have only two normal ports going to the same server."

That statement does not make sense to me.  I thought this to be a routing issue where one switch or the other is chosen as a downlink pathway by a router.  How can a switch know about another switch in a non-aggregated configuration?  Unless you think I'm talking about LAG on a single switch, but I'm not.  The LAG is actually spanned across two non-aggregated switches.
0
 

Author Comment

by:pwyzorski
ID: 21828660
Thanks for the responses, but I'm still looking...
0
 
LVL 21

Assisted Solution

by:from_exp
from_exp earned 1200 total points
ID: 21828686
no, a bit different
in redundant mode, only server has teaming configuration and only one NIC is active at a time, so you don't need to configured lag on switches.
0
 

Author Comment

by:pwyzorski
ID: 21834571
So with the NICs on the host aggregated and no LAG configuration on the switches what we end up with is simple redundancy.  I can get that.

What protocol or protocol aspect defines what switch gets used during a failure event with the primary switch.  Assume simplest scenario with a single router and two switches with multiple hosts connected to both switches.  Is this situation sorted out simply by normal dynamic routing algos?
0
 
LVL 21

Assisted Solution

by:from_exp
from_exp earned 1200 total points
ID: 21834749
I would say you even don't need dynamic routing.
static failover only.
so if you have two switches (connected via LAG, without stack) so you can connect each server to both of them having NICs in redundant LAGs and multiple routers connected each to the appropriate switch. two routers then have vrrp (or cisco's hsrp) running to provide gateway redundancy to PCs
0
 

Author Comment

by:pwyzorski
ID: 21834991
How about a single router connected to both switches?
0
 
LVL 13

Expert Comment

by:kdearing
ID: 21835135
Extreme devices have ESRP which is similar to VRRP/HSRP but also works on their layer 2 switches.
0
 
LVL 21

Assisted Solution

by:from_exp
from_exp earned 1200 total points
ID: 21837061
possible, to do that also, but how would you like to arrage failover?
0
 

Author Comment

by:pwyzorski
ID: 21838414
some reason client isn't opting for failover at the router level... beats me...

I'm done one this, thanks for the help. I'll award points between you two as such:
'from_exp' - 400pts
'kdearing' - 100pts

thanks
0

Featured Post

Free Tool: Path Explorer

An intuitive utility to help find the CSS path to UI elements on a webpage. These paths are used frequently in a variety of front-end development and QA automation tasks.

One of a set of tools we're offering as a way of saying thank you for being a part of the community.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Arrow Electronics was searching for a KVM  (Keyboard/Video/Mouse) switch that could display on one single monitor the current status of all units being tested on the rack.
This article will show how Aten was able to supply easy management and control for Artear's video walls and wide range display configurations of their newsroom.
This course is ideal for IT System Administrators working with VMware vSphere and its associated products in their company infrastructure. This course teaches you how to install and maintain this virtualization technology to store data, prevent vuln…
In a question here at Experts Exchange (https://www.experts-exchange.com/questions/29062564/Adobe-acrobat-reader-DC.html), a member asked how to create a signature in Adobe Acrobat Reader DC (the free Reader product, not the paid, full Acrobat produ…

916 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question