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CCNA ICND
Cisco CCNA ICND book (CIsco Press Book)
Question | Answer |
---|---|
you just unpacked a 2950 from the box what commands are necessary to be able to remotely access the swtich | int vlan1; ip address <addr> <subnet>; ip default-gateway <address> |
how would you set the speed on interface 15 on a 2950 | int f0/15 speed 100 |
how would you set full duplex on port 20 on a 2950 | int f0/20 duplex full |
how would you define port security for a particular mac address | int f0/20 switchport port-security mac-address <addr_here> |
how would you set port security violation of shutdown on port 21 on a 2950 | int f0/21 switchport port-security violation shutdown |
how would you see a one line status on all of the interfaces on a 2950 | show int status |
how would you view port security on interface 10 | show port-security interface f0/10 |
how would you erase a startup configuration on a 2950 | erase startup-config |
how would you view trunking information on a 2950 | show trunk |
how would you view status information on vlan 14 on a 2950 | show interfaces vlan 14 |
how would you view the mac address table on a 2950 | show mac-address-table dynamic |
what is the difference between sticky and non sticky port security | sticky the first time a system is plugged it and packets traverse the switch the mac address associated with that system will stick and any other system will in hence be in violation |
how would you set interface 16 into port-security with a sticky configuration | int f0/16; switchport port-security mac-address sticky |
root bridge is what | the switch that does all of the forwarding based on election |
what protocol defines STP | 802.1d |
the protocol defines the bridge priority field as a N byte field that can contain values of | 2 bytes 0-65535 lower being higher |
with the STP process what happens once a root has been identified | the other switches stop advertising themselves as root and start advertising the hello sent by the better switch except they will increase the cost |
how does a switch determine root port | port with the lowest cost |
what is the cost heirarchy with the new IEEE | 10GB 2; 1GB 4; 100MB 19; 10MB 100 |
what is the default interval for STP on 2950 | 2 seconds |
what is the max time fror STP | 20 seconds 10 times hello before trying to change STP topology |
forward delay is what | delay that affects the time involved when an interface changes from blocking to forwarding. A port stays in listening state and then learning state for a number of seconds defined here |
what happens when a switch no longer hears hellos from the root bridge | after the maxage timer expires the switch will announce itself as the root via hello |
if you have a situation where you have 3 switches and each are connected to eachother and the connection between 1 and 3 fails what happens | after maxage expires switch 3 starts to announce itself as the root bridge, however, hello are still coming in with switch root as the root bridge with a higher cost as going through switch 2. Switch 3 cedes to swtich 1 and sets the link between 3 and 2 |
how long would it take to converge if you have a three switches each connected to eachother and the link between 1 and 3 fails | 50 seconds because 20 seconds for maxage, then transition from listening to forwarding takes forward delay takes 15 seconds, then forward delay to forwarding takes another 15 |
when a switch precipitates a network change what does it do | after the maxage time runs out it sends a Topology change notification (TCN) BPDU out the other port. Other switch gets it and times out all MAC entries using maxage and forwards TCN BPDU to root switch. |
by default it takes 50 seconds to converge all the switches if a link goes down what are some of the best ways to decrease the times it takes to go through that process | make use of etherchannel for trunks STP treats the etherchannel as a single interface |
by default it takes 50 seconds to converge all the switches if a link goes down what are some of the best ways to decrease the times it takes to go through that process | RSTP 802.1w |