Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

IT infrastructuur > 11. BGP > Flashcards

11. BGP Flashcards

1
Q

What is the private range of BGP?

A

64512-65535

4.200.000.000-4.295

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the 4 path attributes?

A

Well-known mandatory
Well-known discretionary
Optional transitive
Optional non-transative

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the difference between well-known mandatory and well-known discretionary?

A

Must be recognized by al BGP implementations

Must be included with prefix advertisement

May or may not be included with a prefix advertisement

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the difference between optional transitive and optional non-transative?

A

Do not have to be recognized by BPG implementations

Transitive will stay with the route advertisement

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the NLRI?

A

Network layer reachability Information, a routing update that Contains: Prefix, prefix length and PAs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the AS_path attribute?

A

Well-known mandatory attribute that remembers the ASs is went through to prevent loops

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What did multi protocol BGP added?

A

AFI - address family identifier - IPv4 of IPv6

SAFI - unicast multicast

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

How does MBGP achieves seperation?

A

With the attributes MP_REACH_NLRI and MP_UNREACH_NLRI

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What port does BGP use?

A

TCP 179

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Can BGP multihop session be esthablished?

A

Yes, but a underlaying routing protocol is needed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are the 2 types if BGP sessions?

A

iBPG - within an AS, AD 200 TTL 255

eBGP - different AS, AD 20 TTL 1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are the 4 BGP packet types?

A

Open
Update
Notification
Keepalive

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the default BGP hold timer?

A

180 for Cisco

keepalive /3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is a neighbor router called?

A

Peer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the Finite-State Mechanism?

A

Table BGP uses to maintain all peers and their operational status

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are the 6 states?

A 
Idle
Connect
Active
OpenSent
OpenConfirm
Established
17
Q

What happens in the Idle state?

A

A TCP is initiated to a peer and it listen for a peer. If an error causes BGP to go back to Idle for the second time the ConnectRetryTimer is set to 60.

Will double every fail after this.

18
Q

What happens in the Connect state?

A

After the three way handshake, CRt is reset and Open message is send to the peer —> OpenSent state

19
Q

What happens in the Active state?

A

New three way handshake, hold timer set to 4 minutes

20
Q

What happens in the OpenSent state?

A
  • Version match
  • AS match
  • IP match
  • RID unique
  • Security parameters

If error –> Idle

21
Q

What happens in the OpenConfirm state?

A

Waits for keepalive or Notification

Keepalive –> Established
Notification or hold timer –> Idle

22
Q

What do keepalives an update messages do?

A

They reset the hold timer

23
Q

What is the command for BGP routing activation?

A

router BPG as-number

neighbor ip remote-as as

24
Q

What happens when you change the RID?

A

All BGP session are being reset

25
Q

How to disable default address family?

A

no bgp default ipv4-unicast

26
Q

What command is used to view active BGP sessions?

A

show bgp afi safi summary

27
Q

What are the prefix types for the local RIB table?

A

Connected –> 0.0.0.0

Static/RP –> next hop IP

28
Q

What are the three BGP tables?

A

Adj-rib-in
Local-rib
Adj-rib-out

29
Q

What are the BGP route processing steps?

A
  • Store the route in Adj-rib-in and apply inbound policy
  • Update local-rib and clear Adj-rib-in
  • Check global RIB if visible, if not leave in local-rib
  • Identify best path
  • Install in global RIB and store in Adj-rib-out
30
Q

What is the command to show the adj-rib-out table?

A

show bpg afi safi neighbor ip advertised-routes

31
Q

What is the command to pick up OSPF in BGP?

A

redistribute OSPF processid

32
Q

What is the command to summarize in BGP

A

aggregate-address ip subnet summary-only

33
Q

What is BGP?

A

A path vector routing protocol that does not contain a complete topology of the network

34
Q

What does a UPDATE message contain?

A

The NLRI. Withdrawn NLRI contains only prefix. Can act as a keepalive.

35
Q

When is a NOTIFICATION message sent?

A

When an error is detected or reset is requested

IT infrastructuur (31 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions