Routing and Switching Concepts Flashcards
RIP(v2) is what kind of routing protocol? What does it use as its metric?
Distance Vector. Hop Count is the metric
OSPF is what kind of routing protocol? What does it use for metrics?
Link State. Link bandwidth is the metric.
EIGRP is what kind of routing protocol? What does it use for metrics?
Hybrid. Uses hop count and link state (bandwidth). EIGRP is a Cisco proprietary routing protocol.
BGP is what kind of routing protocol? What does it use for its metric?
Path Vector. BGP uses AS Path and other attributes which typically need to be manually configured.
What are the Administrative Distances for: Connected Interface, Static Route, EBGP, EIGRP, OSPF, RIP, External EIGRP, and Internal BGP
Connected: 0
Static Route: 1
eBGP: 20
EIGRP: 90
OSPF: 110
RIP: 120
Ext. EIGRP: 170
iBGP: 200
What command on a Cisco router will tell you which routing protocols are running?
show ip protocols
What is a CAM table?
“Content Addressable Memory Table” - contains entries of a MAC address, interface, and VLAN ID in high speed memory of a Switch
What is a TCAM and how is it different from a CAM table?
“Ternary Content Addressable Memory Table” - contains entries of IP address, mask, Result (permit, deny, next hop).
What is the difference between Process Switching and Fast Switching?
Process switching stores packets in memory and relies on the CPU to process forwarding decisions. Fast switching stores forwarding information in cache to alleviate the CPU.
What is the command to enable Fast Switching?
Router(config-if)# ip route-cache
What is CEF?
Cisco Express Forwarding - the next generation of fast switching that uses the Forwarding Information Base to make forwarding decisions. This is enabled by default on all Cisco routers.
What is the difference between the Forwarding Information Base (FIB) and the Routing Information Base (RIB)?
The FIB is populated using information from the RIB. This is what is used by CEF
What information is stored in the FIB?
- Egress Interface (from RIB)
- Next-Hop MAC (from ARP)
What is the difference between centralized and distributed switching?
In distributed switching, the CAM and FIB reside on the line cards of a modular switch where centralized switches need to send all packets to the supervisor card before going to its next hop interface.
