Cisco Best Practice

or What we really use!

• vlans (802.11q)
• stp
• snmp → mrtg
• security - dhcp helper
• more static arp

Something's missing, something's redundant?

• missing - broken cable, lost connection, broken switch
• redundant - badly placed cable, circles the network

STP can fix all of the above.

Redundant layer 2 redundacy problems

• broadcast storm
• multiple frame copies - which is basicly the same
• ARP table instabilities (Cisco: CAM table)

Magic question - what is 32768?

Time tracking

• 20 waiting for no BPDU
• 15 unblock blocked ports and listening state for new BPDUs - topology change
• 15 learning state, accepts all ethernet frames, learns MAC, but doesn't forward

First we obviously need to know, how to disable stp for end host device (designated forwarding port).

conf t
int fa 0/5
    spanning-tree portfast
end

PVST+ <code>

There is no more or less static arp, but the interval could be longer.