SG550-24XG STACKING FAILOVER ISSUE

[Himanshu_Dwivedi]

Hello,

I have a stack of 2 SG550X Managed switches on copper Port with software is 2.3. There are multiple gateways and multiple servers(server 2k19) forming a Ether channel LACP from core switch and there are some pcs connected to both switches with 2 Nic configured via powershell NIC Teaming. Everything thing runs fine. For Failover testing I run continuous ping all the servers from PCS as well as all the gateways.

When I try to check the Failover, I face weird type of issue happens

1. Powering off standby switch cause some 3-4 General Failure, 2-3 RTO the reachable again. Cause interruption in network.

2. I again power on the switch and its becomes standby,  I check via console all the ports are up and including port channel, now I get continuous request time out and destination host unreachable. For restoration I need to shutdown all the ports including port channel, thn it revert back in operational mode.

Can anyone help me in this case, as these switches are being used for industrial automation devices as a core and every fluctuations & RTO matters.

NOTE : I have disabled smartport on interfaces level as well as on global level.

[Reza Sharifi]

Hi,

I am not familiar with the SG model, but I will ask a couple of questions to find clarity.

 there are some pcs connected to both switches with 2 Nic configured via powershell NIC Teaming

Are both NICs using one IP address? If they are using 2, are they on the same subnet?

What happens when you disconnect one of the cables? Does it failover to the other NIC with no issues?

HTH

[Himanshu_Dwivedi]

Hello,

2 Nic are forming a single logical port with single IP address, and both the ports are of same vlan member, when I disable 1 interface from PC there is no impact same thing check with other NIC also.

[Reza Sharifi]

Hi,

Perfect. Thank you for the clear answer! So, to just clarify, you only see the issue when you shut down one of the switches, right?

Also, have you tried to configure mode "on" instead of LACP and test?

HTH

[Reza Sharifi]

Also, is this command available and configured on the SG series? If yes, you may want to try it and test it again.

stack-mac persistent timer 0

[Himanshu_Dwivedi]

Ok this command I will try tomorrow.

[Himanshu_Dwivedi]

Yes tried with this also but no luck. I tried with bridging 2 NIC.