ICND2 Chapter 02 Flashcards
Three classes of Problems caused by not using STP in Redundant LANs
Broadcast storms MAC table instability Multiple frame transmission
STP: All the root switch’s ports Blocking/Forwarding
Forwarding
STP: Each nonroot switch’s root port Blocking/Forwarding
Forwarding
STP: Each LAN’s designated port Blocking/Forwarding
Forwarding
STP: All the other working ports Blocking/Forwarding
Blocking
Fields in the STP Hello BPDU: Root Bridge ID
The bridge ID believed to be the root
Fields in the STP Hello BPDU: Sender’s bridge ID
The bridge ID of the bridge/switch sending this BPDU
Fields in the STP Hello BPDU: Cost to each root
The STP cost between this switch and the current root
Fields in the STP Hello BPDU: Timer values on the root switch
Hello Timer; Max Age timer; Forward Delay timer
Default Port Costs According to IEEE: 10 Mbps
100; 100
Default Port Costs According to IEEE: 100 Mbps
10; 19
Default Port Costs According to IEEE: 1 Gbps
1; 4
Default Port Costs According to IEEE: 10 Gbps
1; 2
STP Timer: Hello
Time between Hello’s; 2 second default
STP Timer: Max Age
How long any switch should wait after last Hello; 10 x Hello default
STP Timer: Forward Delay
Listen State = Forward Delay; Learning State = Forward Delay; 15 second default
IEEE 802.1D Spanning –Tree State Blocking: Forwards Data Frames
No
IEEE 802.1D Spanning –Tree State Blocking: Learns MACs Based on Received Frames
No
IEEE 802.1D Spanning –Tree State Blocking: Transitory or Stable State
Stable
IEEE 802.1D Spanning –Tree State Listening: Forwards Data Frames
No
IEEE 802.1D Spanning –Tree State Listening: Learns MACs Based on Received Frames
No
IEEE 802.1D Spanning –Tree State Listening: Transitory or Stable State
Transitory
IEEE 802.1D Spanning –Tree State Learning: Forwards Data Frames
No
IEEE 802.1D Spanning –Tree State Learning: Learns MACs Based on Received Frames
Yes
IEEE 802.1D Spanning –Tree State Learning: Transitory or Stable State
Transitory
IEEE 802.1D Spanning –Tree State Forwarding: Forwards Data Frames
Yes
IEEE 802.1D Spanning –Tree State Forwarding: Learns MACs Based on Received Frames
Yes
IEEE 802.1D Spanning –Tree State Forwarding: Transitory or Stable State
Stable
IEEE 802.1D Spanning –Tree State Disabled: Forwards Data Frames
No
IEEE 802.1D Spanning –Tree State Disabled: Learns MACs Based on Received Frames
No
IEEE 802.1D Spanning –Tree State Disabled: Transitory or Stable State
Stable
STP (802.1d) State Blocking; RSTP (802.1w) State Discarding; Operational State
Enabled
STP (802.1d) State Listening; RSTP (802.1w) State Discarding; Operational State
Enabled
STP (802.1d) State Learning; RSTP (802.1w) State Learning; Operational State
Enabled
STP (802.1d) State Forwarding; RSTP (802.1w) State Forwarding; Operational State
Enabled
STP (802.1d) State Disabled; RSTP (802.1w) State Discarding; Operational State
Disabled
STP (802.1d) State Blocking; RSTP (802.1w) State Discarding; Forwards Data Frames in This State
No
STP (802.1d) State Listening; RSTP (802.1w) State Discarding; Forwards Data Frames in This State
No
STP (802.1d) State Learning; RSTP (802.1w) State Learning; Forwards Data Frames in This State
No
STP (802.1d) State Forwarding; RSTP (802.1w) State Forwarding; Forwards Data Frames in This State
Yes
STP (802.1d) State Disabled; RSTP (802.1w) State Discarding; Forwards Data Frames in This State
No
RSTP Root port; STP Root port Role Definition
Hears the best BPDU out of all received
RSTP Designated port; STP Designated port Role Definition
The port that advertises the “best” BPDU.
RSTP Alternate port; STP NA Role Definition
Receives the suboptimal BPDU
RSTP Backup port; STP NA Role Definition
A non-designated port on a switch that is attached to the same segment
RSTP Disabled; STP NA Role Definition
Admin disabled or not working port
PVST+ Supports STP
Yes
PVST+ Supports RSTP
No
PVST+ Configuration Effort
small
PVST+ Only One instance required for each redundant path
No
PVRST Supports STP
No
PVRST Supports RSTP
Yes
PVRST Configuration Effort
small
PVRST Only One instance required for each redundant path
No
MIST Supports STP
No
MIST Supports RSTP
Yes
MIST Configuration Effort
medium
MIST Only One instance required for each redundant path
Yes
STP Bridge ID default
Priority: 32768 + VLAN ID; System: A burned-in MAC on the switch; spanning-tree vlan vlan-id root [primary|secondary]; spanning-tree vlan vlan-id priority priority
STP Interface cost default
100 for 10 Mbps; 19 for 100 Mbps; 4 for 1 Gbps; 2 for 10 Gbps; spanning-tree vlan vlan-id cost cost
STP Portfast
spanning-tree portfast
STP BPDU Guard
spanning-tree bpduguard enable