CCNP Switch 学习笔记(非常经典)

General Timers Port ID PortFast and UplinkFast BackboneFast Verification
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Additional features
Root Guard BPDU Guard BPDU Filter Loop Guard UDLD
25
25
VTP version 3 Miscellaneous
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EtherChannel
PAgP LACP, 802.3ad Configuration Algorithm
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29 30 31 32
STP
Type of BDPU Port costs Port states Types of STP STP configuration
Type of MLS
Cisco implements route caching (demand-based) and topology-based switching. Demand-based switching, also known as flow-based switching, or MLS requires 3 components:
CCNP SWITCH
L2 and MLS function
L2 switch Type of MLS TCAM table
5
5 5 6
More about MLS
MLS switching CEF
Advanced CEF
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8 9
9
Fallback bridging Adjacency table Control and data plane Hardware
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VLAN
VLAN 1 Trunk design Trunking protocols InterVLAN routing 802.1Q-in-Q tunneling PPPoE
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21 21 21 22 23 24
VTP
VTP update advertisement
CUWNA roaming Switch configuration
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61 62 62 63
64 65
Security
Port Security
66
66
DHCP snooping Dynamic ARP inspection IP source guard VLAN hopping 802.1x and AAA Switch ACLs PVLAN Other security features Error management
HSRP
HSRP election HSRP messages HSRP states HSRP authentication Interface track HRSP load-balance
49
49
50 50 50 51 51 51
VRRP GLBP
AVG and AVF Weighting feature Load-balance algorithm
44 45
Campus Network Design
Cisco hierarchical design Switch and core block Cisco Enterprise Composite Model
Campus Switched LAN
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48
Gateway Redundancy protocol
L2 switch
When a frame arrives at a switch port, it’s placed into one of the ingress queues. Each ingress queues have a different priority service level, so the higher priority queues gets faster service, this prevents time (latency: the time takes from a frame enters the switch to leaving it) sensitive frames from being last. Not only does the switch has to figure out WHERE to send a frame, it also has to figure to WHETHER it should and HOW. These are the factors affecting the process, each is operated separately: - L2 forwarding table, or CAM table. - Security ACL placed in ternary CAM or TCAM table deciding whether a frame should leave - QoS ACL determines which egress queue a frame will go, each queue has different priority to prevent time-sensitive information from delay. Also stored in TCAM table. When frames come in, all ACLs are run in parallel to match the frame. When a packet comes in, these components will be involved in its forwarding decision: L2 forwarding, or CAM table. L3 forwarding, or FIB table Security ACLs compiled into TCAM table QoS ACLs compiled into TCAM table
Catalyst 5000/5500 Catalyst 3750 Catalyst 4500
10 10 11 12
12 14 14
Catalyst software, Cat OS
15
Cables and connectors
Fast Ethernet Gigabit Ethernet 10 Gigabit Ethernet Autonegotiation Summary
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L2 and MLS function
A Layer 2 switch mimics a transparent bridge, which offers segmentation while being transparent to all end devices. Whenever a frame with an unknown source address enters the switch, its source MAC address, along with switch port number and VLAN are recorded in the CAM table. Time stamps are also added (every time a frame from that device is sent out) so the CAM table know the latest entry, if newer time stamp of this device is found in another port, and the switch no longer hears from that device (at the old port), this entry is deleted and the new entry is used instead (of normal 300 second age out). By default, MAC address table age out an entry after 300 second of inactivity (5 minutes). But you can manually adjust this by ‘(config)#mac address-table aging-time SEC’. You can also configure a static entry of MAC address so it doesn't leave the CAM table unless you specified so, by ‘(config)#mac address-table static MAC_ADD vlan V_ID interface TYPE_NO’ To display the MAC address table, use ‘#show mac address-table dynamic [address MAC_ADD | interface TYPE_NO | vlan VID]’. To delete an entry, add ‘clear’ in front of the command. To see the CAM table size, use ‘show mac address-table count’ command.
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RSTP
BPDU Port Synchronization Topology Change Compatibility RSTP, RPVST+, and MST