Terminology 4 Flashcards
(100 cards)
1
Q
AD is used to rate what?
A
The trustworthiness of routing information.
2
Q
What are the minimum and maximum AD?
A
0, 255
3
Q
What does an AD of 255 mean?
A
No traffic is allowed to be passed via this route.
4
Q
What happens when multiple routing protocols are running on a router?
A
Only the routes from the protocol with the lowest default AD will be on the routing table.
5
Q
What is the default AD for connected interfaces?
A
0
6
Q
What is the default AD for static routes?
A
1
7
Q
What is the default AD for External BGP?
A
20
8
Q
What is the default AD for Internal EIGRP?
A
90
9
Q
What is the default AD for IGRP?
A
100
10
Q
What is the default AD for OSPF?
A
110
11
Q
What is the default AD for IS-IS?
A
115
12
Q
What is the default AD for RIP?
A
120
13
Q
What is the default AD for External EIGRP?
A
170
14
Q
What is the default AD for Internal BGP?
A
200
15
Q
What is the default AD for unknown?
A
255
16
Q
What three tables do Link State routing protocols keep?
A
- Directly attached neighbours
- Topology of the entire network
- The actual routing table
17
Q
When distance vector routing protocols pass their routing tables to their neighbours, what is this known as?
A
Routing by rumour.
18
Q
If two routes are received with the same AD, how does the protocol choose a route?
A
The protocol uses other metrics.
19
Q
In DV routing, if the AD is the same and the hop count is the same, what does the router do?
A
It uses round-robin load balancing.
20
Q
What normally happens to data transmission when routers are converging?
A
It stops
21
Q
How often does RIP send out a complete routing table to all active interfaces?
A
Every 30 seconds.
22
Q
What is RIP’s maximum allowable hop count
A
15
23
Q
Why does RIP limit the allowable hop count to 15?
A
To prevent routing loops.
24
Q
Why can RIP cause latency in a network?
A
Slow convergence.
25
Does RIP support classful routing?
No, all devices must use the same subnet mask for each specific address class.
26
Why is RIPv2 considered classless?
Because subnet information is sent with each route update.
27
Is RIP open standard or proprietary?
Open standard.
28
RIPv1 uses broadcasts to send routing information to neighbours. What does RIPv2 use (and what address)?
Multicast 224.0.0.9
29
What authentication do RIP and RIPv2 support?
RIP - none
RIPv2 - MD5
30
Do RIP and RIPv2 support VLSM?
RIP - no
RIPv2 - yes
31
What 3 routing protocols send subnet mask information with route updates?
RIPv2
OSPF
EIGRP
32
What is a discontiguous network?
One that has two or more subnets of a classful network connected together by different classful networks
33
Discontiguous networks work with which protocol?
OSPF
34
What is route aggregation?
Combining multiple subnets into one larger subnet.
35
What is another name for route aggregation?
Supernetting.
36
What link-state characteristic does EIGRP have, making it a hybrid protocol?
It synchronises routing tables between neighboursat startup, and then only sends specific updates only when topology changes occur.
37
Does EIGRP support IPv6?
Yes, EIGRPv6 does
38
Does EIGRP support summaries and discontiguous networks?
Yes
39
With EIGRP, what is RTP?
Reliable Transport Protocol
40
What is DUAL?
Diffusing Update Algorithm
41
What is a 'successor' route?
The best route to a remote network
42
What is the backup route to a remote network called in EIGRP?
Feasible successor route
43
What is route redistribution
Translating from one routing protocol to another
44
BGP is a ____ _____ routing protocol
Path vector
45
What is the routing table in BGP called?
Routing Information Base (RIB)
46
What are Hello packets used for?
To maintain the neighbour table in link-state routing
47
How is the topology table maintained?
Via Link State Advertisements, or Packets (LSAs or LSPs).
48
What does a topology table contain?
A list of all destination networks plus every neighbour they can be reached through.
49
SPF
Shortest Path First
50
What algorithm does OSPF use?
The Dijkstra algorithm
51
Which converges faster, OSPF or EIGRP?
EIGRP
52
Does OSPF support auto summarisation?
No
53
What is the OSPF area connected to the backbone called?
Area 0
54
What are routers that connect other areas to the backbone area within OSPF called?
ABRs (Area Border Routers)
55
What is the router that connects two ASs in OSPF called?
ASBR (Autonomous System Border Router)
56
In IS-IS where do L1 intermediate systems route?
Within an area
57
In IS-IS where do L2 intermediate systems route?
Between areas and toward other ASs
58
CLNS
Connectionless Network Service
59
What is CLNS used for
In IS-IS to provide connectionless delivery of data packets between routers (OSPF uses IP)
60
Why do ISPs prefer IS-IS over OSPF?
It can run IP and IPv6 without creating a separate database for each protocol like OSPF does.
61
FHRP
First Hop Redundancy Protocol
62
HSRP
Hot Standby Routing Protocol
63
How can you achieve load balancing with HSRP?
Set up different VLANs and designating different routers as active for that VLAN
64
VRRP
Virtual Router Redundancy Protocol
65
What routers are defined in an HSRP group?
Active router
Standby router
Virtual router
any other routers that may be connected to the subnet.
66
What is the drawback with HSRP?
Only one router is active, the others do nothing.
67
What happens if the HSRP standby router does not receive Hello packets from the active router?
It takes over the active router role.
68
What is the makeup of the HSRP virtual MAC address:
0000.0c07.ac.0a
0000.0c - Vendor ID (Cisco)
07.ac - The well-known HSRP ID
0a - the HSRP group number
69
What are the 4 HSRP timers?
1. Hello
2. Hold
3. Active
4. Standby
70
What is the HSRP hello timer, and what is its default interval?
They identify the state that each router is in. The default is 3 seconds.
71
Roughly what sort of time can the HSRP hello timer be set to?
milliseconds
72
What is the HSRP hold timer, and what is the default setting? What is the recommended setting if the hello timer is changed?
It is the interval the standby router uses to determine whether the active router is offline. The default is 10 seconds. The recommendation is to set it 3 times the hello timer.
73
What is an HSRP active timer?
It monitors the state of the active router, it resets each time a router in the standby group gets a hello packet from the active router.
74
What is an HSRP standby timer?
It monitors the state of the standby router, it resets each time a router in the standby group gets a hello packet from the standby router,
75
What is the virtual router that represents a group of VRRP routers called?
The VRRP group
76
What is the active router in a VRRP group called?
The master router
77
Which router in a VRRP group can have the same IP address as the group?
The master router
78
What are the standby routers in a VRRP group called?
Backup routers
79
In IPv6, what is the purpose of router advertisement?
To send a network ID (called a prefix in IPv6) to a host, so it can generate its own IPv6 address.
80
In IPv6, what is a router solicitation (RS)?
It is a multicast packet to all routers for prefix information (FF02::2).
81
What is the ICMP message type for RS?
133
82
What is the multicast address and ICMP type of an RS?
FF02::1
134
83
What prefix does a link-local address always use?
FE80::/64
84
What is Neighbour Discovery Protocol used for?
IN IPv6, NDP is used to learn the link local addresses of other hosts in its subnet.
85
What is the ICMP type of a Neighbour Solicitation message in IPv6?
135
86
What are the three key pieces to configure a 6to4 tunnel?
1. The tunnel mode
2. The IPv4 tunnel source
3. A 6to4 IP address that lies within 2002::/16
87
What are the parts of a /48 automatic 6to4 tunnel prefix?
2002:nnnn:nnnn
where nnnn:nnnn is the IPv4 address in hex
88
ISATAP
Intra-Site Automatic Tunnel Addressing Protocol
89
What is a risk with NAT and 6to4 tunneling?
Nat can break the tunnel encapsulation
90
What is the advantage of Teredo to give IPv6 functionality to hosts on an IPv4 network?
It can do so from behind NAT devices
91
What does Teredo do essentially?
Encapsulates IPv6 packets inside UDPv4 datagrams
92
What is a Teredo client?
A host with IPv4 connectivity that uses Teredo to access the IPv6 internet
93
What is a Teredo server?
The host used for initial configuration of a Teredo
94
What is a Teredo relay?
The remote end of a Teredo tunnel.
95
What is a Teredo Host-Specific Relay?
A relay whose range is limited to the host it runs on.
96
What is the multicast address that RIPng uses?
FF02::9
97
What are 3 IPv6 routing protocols?
RIPng, EIGRPv6, OSPFv3
98
What is EIGRPv6's multicast address?
FF02::A
99
What are the 2 multicast addresses for OSPFv3
FF02::5 (OSPF routers)
FF02::6 (OSPF-designated routers)
100
SPB
Shortest Path Bridging
