<\/p>\n
Symptoms<\/h4>\n
If one side sends “Full Duplex” and the other is only “Half Duplex”, there will be numerous collisions and everything will be slow.<\/p>\n
Solution<\/h4>\n
Set the switchport listed in the error (0\/1) to match the device.<\/p>\n
Sw1(config)#interface fastethernet 0\/1<\/span>\r\nSw1(config-if)#duplex half<\/span>\r\n%LINK-5-CHANGED: Interface FastEthernet0\/1, changed state to down\r\n%LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0\/1, changed state to down\r\n%LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan1, changed state to down\r\n%LINK-5-CHANGED: Interface FastEthernet0\/1, changed state to up\r\n%LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0\/1, changed state to up\r\n%LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan1, changed state to up\r\n<\/pre>\nSet the Speed<\/h4>\nSw1(config-if)#speed 10<\/span><\/pre>\n <\/p>\n
Recommendations<\/h4>\n
Allow PCs to “Auto Detect”<\/p>\n
Manually configure these to ensure the settings are correct.<\/p>\n
\n- Servers<\/li>\n
- Routers<\/li>\n
- Printers<\/li>\n
- Other Switches (using cross-over cables)<\/li>\n<\/ul>\n
<\/p>\n
Optimizing Your Switch<\/h3>\n
These probably won’t be on the test, but good to know (or at least to know about!)<\/p>\n
Stop messages from splitting commands<\/h4>\n
Example:<\/p>\n
Sw1#show<\/span>\r\n%SYS 5 CONFIG I: Configurd from console by thomas on vty0 (172.2.30.100) ip ...<\/span>\r\n<\/pre>\nCommands for Console and Telnet:<\/p>\n
Sw1(config)#line console 0<\/span>\r\nSw1(config-line)#logging synchronous<\/span>\r\nSw1(config-line)#exit<\/span>\r\nSw1(config)#line vty 0 4<\/span>\r\nSw1(config-line)#logging synchronous<\/span>\r\n<\/pre>\nResult:<\/p>\n
Sw1#show<\/span>\r\n%SYS 5 CONFIG I: Configurd from console by thomas on vty0 (172.2.30.100)\r\nSw1#show ip ...<\/span>\r\n<\/pre>\n <\/p>\n
Setting the Idle Timer<\/h4>\n
By default the Idle Timer is set to 5 minutes.
\nExample: Set to 30 minutes and 0 seconds<\/p>\n
Sw1(config)#line console 0<\/span>\r\nSw1(config-line)#exec-timeout 30 0<\/span>\r\nSw1(config-line)#exit<\/span>\r\nSw1(config)#line vty 0 4<\/span>\r\nSw1(config-line)#exec-timeout 30 <\/span>\r\n<\/pre>\nTo disable the timeout completely:<\/p>\n
Sw1(config-line)#no exec timeout<\/span><\/pre>\n <\/p>\n
Fixing Typo Delays (Due to domain lookups)<\/h4>\n
If you enter a typo, the switch will try to locate the mis-typed word as a domain. This can cause long delays before the prompt is displayed
\nExample:<\/p>\n
Sw1#flow<\/span>\r\nTranslating \"flow\"...domain server (255.255.255.255)\r\n...long delay!...\r\n% Unknown command or computer name, or unable to find computer address\r\nSw1#_\r\n<\/pre>\nCommand to disable this feature<\/p>\n
Sw1(config)#no ip domain-lookup<\/span><\/pre>\nResult:<\/p>\n
Sw1#flow<\/span>\r\n% Unknown command or computer name, or unable to find computer address\r\nSw1#_\r\n<\/pre>\n <\/p>\n
Creating Aliases<\/h4>\n
Aliases may be create for the “Mode” you are in, so the same alias can mean different things depending on the operating mode
\nExample: Create Alias for Privilege Mode (Exec Mode)<\/p>\n
Sw1(config)#alias exec s show ip interface brief<\/span><\/pre>\nResult:<\/p>\n
Sw1#s<\/span>\r\nInterfaces IP Address OK? .....\r\nVlan1 172.2.30.180 YES ..... \r\n...\r\n<\/pre>\n <\/p>\n
Spanning Tree Protocol<\/h3>\n
“Spanning Tree blocks redundancies to prevent loops.”
\nDesigned to prevent loops caused by broadcasts between multiple devices with redundant connections.
\nThis is known as a Broadcast Storm<\/b>
\n![\"SpanningTreeFailExample\"](\"http:\/\/wiki.thomasandsofia.com\/wp-content\/uploads\/2015\/09\/SpanningTreeFailExample.png\")
<\/a><\/p>\nSpanning Tree Protocol will drop trees on redundant links until they are needed.<\/p>\n