Lammle questions Flashcards
Enable Rapid Spanning Tree. Config
Switch(config)#spanning-tree mode rapid-pvst
How do we know a spanning-tree network has converged?
All switch and bridge ports are assigned as either root or designated ports. When all bridges/switches have transitioned to either forwarding/blocking state.
What are the two types of EtherChannels? What modes enable each?
Two types of EtherChannel: Cisco proprietary PAgP and the IEEE’s LACP.
For PAgP, use auto or desirable mode, and with LACP use passive or active
What can you do to provide two switches higher bandwidth than the default configuration is already providing?
Place the links in the same EtherChannel bundle. Up to 8 ports between switches.
What would put switch interfaces into EtherChannel port number 1, using LACP?
Switch(config)#interface port-channel 1
Switch(config-if)#channel-group 1 mode active
What two commands would guarantee your switch to be the root bridge for VLAN 30?
spanning-tree vlan 30 priority 0
spanning-tree vlan 30 root primary
Difference between TACACS+ and RADIUS
TACACS+ is Cisco proprietary (uses TCP also, port 49) (all AAA packets encrypted too) (multiprotocol support) (for devi ce administration)
RADIUS is an open standard (uses UDP also, port 1646/6, 1812/3) (only passwords encrypted) (authentication and authorization is combined) (for network access)
Difference between SNMP v2 and v3
SNMP v2 sends passwords as clear-text (also UDP). SNMP v3 can authenticate and encrypt
SNMP v3 three security modes and definitions
noAuthNoPriv: username authentication but no encryption
authNoPriv: MD5 or SHA (Secure Hash Algorithm) authentication but no encryption
authPriv: MD5 or SHA authentication and encryption
Enable AAA on a router
aaa new-model
in global config mode
What mitigates access layer threats?
Port security, DHCP snooping, dynamic ARP inspection, and identity-based networking
What does DHCP snooping do?
DHCP snooping validates DHCP messages, builds and maintains the DHCP snooping binding database, and rate-limits DHCP traffic for trusted and untrusted sources.
What are the HSRP (Hot Standby Router Protocol) states?
INIT, Learn, Listen, Speak, Standby, Active
HSRPv1 and HSRPv2 attributes
Group #:
Virtual MAC address:
Multicast Address:
Port:
HSRP v1 Group #: 0-255 Virtual MAC address: 0000.0c07.acxx Multicast Address: 224.0.0.2 Port: UDP port 1985
HSRP v2 Group #: 0-4095 Virtual MAC address: 0000.0c9f.fxxx Multicast Address: 224.0.0.102 Port: UDP port 1985
You want to configure RADIUS so your network devices have external authentication, but you also need to make sure you can fall back to local authentication. Which command will you use?
aaa authentication login default group MyRadiusGroup local
What is Dynamic ARP Inspection (DAI)?
A security feature that verifies address resolution protocol (ARP) requests and responses in a network
Requires DHCP snooping for MAC-to-IP bindings
Three roles for IEEE 802.1x standard
Client, authenticator, and authentication server
What tables does EIGRP maintain in RAM
Neighbor, topology, and routing
What do you do when troubleshooting EIGRP adjacency?
Interfaces between the devices are down.
The two routers have mismatching EIGRP autonomous system numbers.
Proper interfaces are not enabled for the EIGRP process.
An interface is configured as passive.
K values are mismatched.
EIGRP authentication is misconfigured
What must match for two OSPF routers to become neighbors?
Area ID, stub area flag, authentication password if using one