3x 2530 Switch in a chain

[MarbleCoconut]

Hi All,

I have three 2530 switches that i'm trying to chain together. I'm doing this with SFP modules. The config I have works just fine between two switches. However as soon as i add another switch they all stop communicating, unable to ping between switches. 

I have trunked the SFP ports & set all vlan's as tagged traffic.

Here is a pastebin of my config. These are the same on all switches aside from IP address changes: https://pastebin.com/np4i9HuQ

Also all switches are running  YA.16.04.0016

I think i'm just missing something obvious but.. not sure what the issue is here.

Any help would be appreciated. 

Thanks

[pjm-nps]

Which ports are connected to each switch in the chain?

[parnassus]

First, use lacp instead of trunk for your trunk(s).

Second, if you're chaining three Switches the one on the middle (SW2) needs to have two trunks (aggregated logical ports) trk1 49+50 and trk2 51+52, one to be used to connect to first Switch SW1 and the other one to connect to third Switch SW3. This means that SW1 and SW3 should have, each one, just one trunk trk1 with - necessarily - two ports (say 49 and 50 for both) used to connect to, respectively, trk1 and trk2 both on SW2.

Third, I'll leave all trunks of all Switches untagged members of VLAN 1 and just tagged members of all others VLANs you want to be transported between all of them.

[MarbleCoconut]

Hi,

So the switch 1 has port 49 uplinking to port 52 on the 2nd switch. Then port 49 uplinks to port 52 on the third switch.

Thanks!

[MarbleCoconut]

Hi Parnassus,

Thank you for your reply.

In my end setup i will need to chain together eight switches. Would the process change, or should i just flip between trk1 & 2?

Thanks

[pjm-nps]

If you are only connecting each switch with one port to each other switch you would have no trunks at all. Trunks (as far as HP switches are concerned) are for aggregating multiple ports together to act as one. This isn't to be confused with some other switches concept of a "trunk port" being a port with multiple VLANs.

[MarbleCoconut]

Hi Pjm,

Yeah i did try this.. I'll try again on Friday. Should I just run regular untagged on vlan1?

Thanks

[pjm-nps]

You can do tagged or untagged on vlan1, as long as it matches on both ends. There can be convenience advantages to keeping it untagged, but either way should work.

The key thing for your described setup is to get rid of the trunks and assign the vlans to the single port on each end of each connection, making sure the assigned vlans match on each end.

[parnassus · Accepted solution]

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@MarbleCoconut wrote:

Hi Parnassus,

Thank you for your reply.

In my end setup i will need to chain together eight switches. Would the process change, or should i just flip between trk1 & 2?

Thanks

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The process doesn't change.

Suppose trk 1 is 49+50 and trk2 51+52, then it's just a chain:

SW1 trk 1 <--> trk1 SW2 trk 2 <--> trk 1 SW3 trk 2 <--> trk 1 SW4 trk 2 <--> ... SWn ... <--> trk 1 SW8

or, if you prefer:

SW1 trk 1 <--> trk 2 SW2 trk 1 <--> trk 2 SW3 trk 1 <--> trk 2 SW4 trk 1 <--> ... SWn ... <--> trk 2 SW8

In any case link aggregated groups "trkn" don't necessarily need to match between adjacent peers (so you can do trkn <--> trkm or whatever you want)...a particular numbering scheme is just something that should help you in identifying rapidly and easily a particular aggregated uplink among others IMHO.