Cisco SG350-28 LAG

[sam7611]

Hi all

I'm attempting to use 4 cisco SG350-28 switches connected around 100 meters apart. 3 switches will connect to 1 "central switch", each using a LAG (the far away switches are using SFP fiber modules). I have this setup and all seems to be working including the 3 VLANs I'm using on the trunked LAG (LACP is being used).

Like i say, it works, however the speed shown on the "LAG Settings" page is 1000M. I attempted to use the cli to gain more information on the EtherChannel but appears those commands don't work on these switches. i would expect each link to be running at 2000M, unless this speed indicator is showing "speed per port within the LAG".

STP also doesn't appear to have disabled one of the links so i am assuming the lag is correctly formed, which is also correctly showing its 2 active members on both sides

the smart network application also appears to show the lag visually working as i would expect it to. 

The redundancy of the links work, but i don't have a way to verify the bandwidth of the lag 

Any advice on what may be going on here is welcome. apologies for the grainy photos attached

Thanks in advance,

Sam

[Reza Sharifi · Accepted solution]

Hi Sam,

Like i say, it works, however the speed shown on the "LAG Settings" page is 1000M

That is the correct behavior. Adding multiple physical links to a portchannel does not increase the bandwidth but rather eliminates STP blocking and provides link redundancy and packet distribution. 

https://www.cisco.com/c/en/us/support/docs/lan-switching/etherchannel/12023-4.html

HTH

[sam7611]

Thankyou for your speedy reply Reza.

This makes sense. so it is essentially showing the speed on a per port basis. 

Thankyou,

Sam