spanning-tree

[balen]

hi guys 

I have a network one off switch are Root after I make another one switch root primary now network all up why...?

[balaji.bandi]

Depends on how the configuration,  (if you do not allow the VLAN in trunk, so there is no Loop)

STP should block the VLAN if you see the loops -  show spann brief on all switch give you information.

[balen]

but it doesn't make it too hard for network or sw if its all painful

[balaji.bandi]

but it doesn't make it too hard for network or sw if its all painful

Not sure i understand your query here ?

[balen]

before using spanning-tree one link down now after using spanning-tree all the switch were up

[balaji.bandi]

spanning tree only Blocks based on the Loops prevention, it does not shutdown the port - as mentioned.

https://blogs.cisco.com/networking/preventing-network-loops-a-feature-you-need-to-be-aware-of

Loopback Detection Settings

Loopback Detection (LBD) provides protection against loops by transmitting loop protocol packets out of ports on which loop protection has been enabled. When the switch sends out a loop protocol packet, and then receives the same packet, it shuts down the port that received the packet.

Loopback Detection operates independently of STP. After a loop is discovered, the port that received the loops is placed in the Shut Down state. A trap is sent and the event is logged. Network managers can define a Detection Interval that sets the time interval between LBD packets.

The following loop cases can be detected by the Loopback Detection protocol:

• Shorted wire—Port that loop backs all receiving traffic.

• Direct multi-ports loop—Switch is connected to another switch with more than one port and STP is disabled.

• LAN segment loop—Switch is connected with one or more ports to a LAN segment that has loops.

[paul driver]

Hello

All links will be up but stp will be blocking on those links, per vlan or per instance.

[balen]

that is what I'm doing after using spanning-tree  all the link that were up 

[MHM Cisco World]

depend if you use PVST then all will be UP but show spinning tree show us what VLAN is block in each link.
STP is different than PVST 
STP one root for all VLAN
PVST can config different root for each VLAN.