JA Net+ Ch10 Flashcards
What does the router ASBR acronym mean?
P. 316
Autonomous system border router.
What is ASBR?
P.316
A router that exchanges routing information with routers belonging to other AS (Autonomous System). Such a router advertises AS external routing information throughout the Autonomous System. The paths to each AS boundary router are known by every router in the AS. AS boundary routers may be internal or area border routers, and may or may not participate in the backbone.
Intermediate system-to-intermediate-system
P.316
IS-IS is a link state routing protocol, meaning it operates by reliably flooding topology information throughout a network of routers.
What is the similarity between IS-IS and OSPF?
P.316
They both employ the Dijkstra algorithm to discover the shortest path through the network to a destination network.
First hop redundancy protocols (FHRPs)
P.317
FHRPs work by giving you a way to configure more than one physical router to appear as if they were only a single logical one, making client configuration and communication easier.
Which protocol is Cisco’s “favorite” method of fault tolerance for routers?
P.319
Hot Standby Router Protocol (HSRP). “Don’t just buy one router, buy up to eight routers!”
What is the one problem with HSRP?
P.319
Only one router is active at a time and two or more routers just sit there in standby mode and won’t be used unless a failure occurs. - not very cost effective or efficient!
Virtual Router Redundancy Protocol (VRRP)
P.319
Provides a redundant (but not load balancing) gateway for hosts on a local subnet.
Virtual MAC Address
P.320
A virtual router in an HSRP group has a virtual IP address and a virtual MAC address. The virtual MAC address is created with HSRP, it creates a totally new made up one.
HSRP MAC address bit sections definitions (example)
0000.0c07.ac0a
0000.0c07.ac0a
First 24 Bits (0000.0c) are the vendor ID of the address. Next 16 Bits (07.ac) are the well-known HSRP ID. This part of the address was assigned by Cisco in the protocol, so it’s easy to recognize this address is for use in HSRP
Last 8 Bits (0a) are the only variable bits and represent the HSRP group number that you assign.
HSRP Timers
P.322
These ensure communication between the routers.
T/F HSRP is an IEEE standard for router redundancy?
P.324
False. VRRP is an IEEE standard and HSRP is a Cisco Proprietary protocol.
Which port does RIPng use?
P. 325
UDP port 521
EIGRPv6 P.325
EIGRPv6 is an advanced distance vector protocol that has some link state features. Hello packets and updates are sent using multicast transmission, and as with RIPng, EIGRPv6’s multicast address stayed almost the same.
OSPFv3 P.325
The new version of OSPF, but the foundation remains the same- It’s a link state routing protocol that divides an entire internetwork or autonomous system into areas, making a hierarchy.
