Internet up down

[Hayat Zarin]

hello every one hope all doing well .

i have core switch's cbs350 stack and access switch's cisco 2960  , core switch connect with FortiGate 601f  firewall before stacking primary switch work properly when stack configure and connect access Switch's with secondary switch then the core Switch's restart by default and secondary Switch not working  .

Access switch's stp portfast and dhcp snooping trust enable 

also check Mac add table its ok 

i upload the topology also 

[Mark Elsen]

                   >...then the core Switch's restart
 - Check logs on the core switch(es) when that happens and or configure a syslog server for follow up on logging, 

 M.

[Hayat Zarin]

ok thank you Sir .

but with trunk link do like that when i configure access port on a core switch & also on the access switch for one Vlan then its work properly no down up satiation.

[Mark Elsen]

 - In general you will provide trunk links between access layer switches and the core ; make sure that the vlan domain is consistent , for instance and that the core is the root for spanning tree , 

 M.