0

Right now we have two independent switch stacks jointed with a single ethernet cable. For throughput and redundancy I would like to join them with a LAG. One switch stack is made up of Dell 7048's, the other is Dell 8132's (now called N4000 I believe). See diagram below.

switch diagram

I cannot for the life of me figure out how to create a LAG between these switches. The ports in question are all on the same subnet (marked blue in the diagram) so there is no VLAN tagging / trunking required, I think. I just want all the blue ports to behave as one switch. I also cannot figure out how and whether LACP comes into play.

Can someone please either provide me with specific instructions or guide me to a specific tutorial about what settings I should be using? I prefer using the web admin GUI but I do have serial access to the devices if need be. Any advice or guidance would be much appreciated.

3
  • Don't use LACP between switches if they are in same places. LACP won't give you the best load-balance. Use LAG without LACP, it's the same as roundrobin. – Mikhail Khirgiy Dec 16 '16 at 5:52
  • I have no idea what this other guy is saying, if you want the bandwidth, put all ports in the same port channel(1/1,1/2,2/1,2/2), I'd recommend static lag. – Jacob Evans Dec 16 '16 at 6:02
  • I erased my other comment as I didnt realized the switch were stacked. I would do like Jacob's told – yagmoth555 Dec 16 '16 at 11:57
3

In the GUI it's simple to create the LAG, check the below print screen. You need to add the port you need to the same group, by clicking and adding each ports.

enter image description here

Note: In the GUI when you create the LAG you can click to enable LACP, be advised that once the LAG is created you can't enable LACP without destroying the LAG first.

In the CLI: (without LACP)

console# configure

Enter configuration mode.

console(config)# interface range gi1/0/1-4

Enter interface-range configuration mode by entering the range of interfaces to be configured. Range command is optional.

console(config-if)# channel-group 1 mode on

Assign Group and mode static. This creates port-channel 1 as static LAG. The number is only relevant to this specific switch. Although it best practice to match the number on the corresponding switch for ease of management.

console(config-if)# end

Exit configure mode.

console# copy running-config startup-config

(Optional) Save your entries in the configuration file.

Don't forget to configure both switch.

Some reference: How to create Link Aggregation Groups (LAGs) on Dell Networking PowerConnect Switches

2
  • Thank you for your answer, this is helpful. A followup question: Do I need to do anything special to allow specific VLAN traffic on the new "port-channel 1" or will it just assume the same VLAN settings as the individual ports had? – Hank Dec 19 '16 at 16:47
  • @HenryJackson You need to doublecheck there for VLAN assignment to a LAG; Network Administration > Spanning Tree and LAG > Link Aggregation (LAG) > VLAN LAG Settings. – yagmoth555 Dec 20 '16 at 3:58
1

without access to the switch, generally this is the process for a lag.

  1. remove all interface configuration for lag members
  2. join the lag

    chanel-group 1 mode on

static: mode on lacp: mode auto

  1. configure your lag (pass vlans or access ports, the config is the same as an interface)

    interface port-channel 1 switchport mode trunk

whatever you do on the top stack, do the same for the bottom.

depending on your needs, you typically want static lag, unless you use virtual port channels, vlt, or the endpoints only support one or the other.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.