Connectivity Issues

harrisfed · ‎08-06-2023

We've encountered an unusual issue within our network configuration.

Our core switch is an SG550X 24 Port 10Gb SFP+ Switch, and we are using SG350X switches for edge switching.

When we configure Switch A and connect it directly to the core, everything functions as expected. However, a problem arises when we attempt to add another switch, Switch B, by connecting it to Switch A. In this configuration, Switch B has no connectivity. Interestingly, if we take Switch B and plug it directly into the core, it works perfectly.

We have verified that we are running the latest firmware, and we have carefully reviewed the configuration, including the setup of 2x 10Gb trunk LAGs.

When examining Switch A's ARP table, we can see an entry for Switch A, but there is no entry for Switch B.

Any assistance with this perplexing issue would be greatly appreciated.

marce1000 · ‎08-06-2023

- If possible connect everything directly to the core for optimized networking. In cascade ; for instance check the logs on all involved devices when the intended links and connections are being made. Also verify the port statuses (should be up running and connected (e.g.)). On SGxxx devices it can be useful to disable the auto smartport feature which can sometimes cause trouble (too)

M.

-- Each morning when I wake up and look into the mirror I always say ' Why am I so brilliant ? '
When the mirror will then always repond to me with ' The only thing that exceeds your brilliance is your beauty! '

Flavio Miranda · ‎08-06-2023

Hi @harrisfed

When you say there is no connectivity, do you mean you ca not ping? Or are you facing layer2 connectivity problem like Interface not coming up?

If the problem is ping, which means layer3 connectivity, try to enable ip routing on switch A. Put the Interface in trunk if you are handling mode then one vlan.