router and switches questions

[Just Kennie]

1. How do I short down ports on a router ?

2. Is debug allowed/advisable in a CCIE lab ?

3. I have many switches connected,with diff vlans assign to port, is it possible I detect broadcast or loop on any port,on any vlan on any switch

[Giuseppe Larosa]

Hello Just,

1)

not sure I've understood question

int type x/y

shut

or no shut

2) you will have privilege level 15 so yes

3) not clear to me

However, to prevent bridging loops:

never use spanning tree bpdu filter

use spanning-tree bpduguard enable on portfast access ports

you can take advantage of spanning-tree loop guard on uplinks (configured on all devices both sides)

When a bridging loop happens you realize it by:

cpu going to 100% on core switches, limited to no access on switches.

Hope to help

Giuseppe