Shulou(Shulou.com)06/03 Report--

BGP configuration

Ideas and configuration:

1. Configure AR5 0 port ip:192.168.12.1 24

Create loopback 0 ip:192.168.100.1 24

Create loopback10 ip:10.10.1.1 24

two。 Configure AR6 0 port ip:192.168.12.2 24

1 port ip:192.168.23.1 24

Create loopback10 ip:10.10.2.2 24

3. Configure AR7 0 port ip:192.168.23.2 24

Create loopback 0 ip:192.168.200.3 24

Create loopback10 ip:10.10.3.3 24

4. Configure AR5 OSPF

Ospf route-id 1.1.1.1

Area 0

Network 192.168.12.0 0.0.0.255

Network 10.10.1.0 0.0.0.255

5. Configure AR6 OSPF

Ospf route-id 2.2.2.2

Area 0

Network 192.168.12.0 0.0.0.255

Network 192.168.23.0 0.0.0.255

Network 10.10.2.0 0.0.0.255

6. Configure AR7 OSPF

Ospf route-id 3.3.3.3

Area 0

Network 192.168.23.0 0.0.0.255

Network 10.10.3.0 0.0.0.255

At this time, the ports can communicate with each other.

7. Configure AR5 BGP

Bgp 64512

Route-id 1.1.1.1

Confederation id 200

Peer 10.10.2.2 as-number 64512

Peer 10.10.2.2 connect-interface loopback 10

8. Configure AR6 BGP

Bgp 64512

Route-id 2.2.2.2

Confederation id 200

Confederation peer-as 64513

Peer 10.10.3.3 as-number 64513

Peer 10.10.3.3 connect-interface loopback 10

Peer 10.10.3.3 ebgp-max-hop

Peer 10.10.1.1 as-number 65412

Peer 10.10.1.1 connect-interface loopback 10

9. Configure AR7 BGP

Bgp 64513

Route-id 3.3.3.3

Confederation id 200

Confederation peer-as 64512

Peer 10.10.2.2 as-number 64512

Peer 10.10.2.2 connect-interface loopback 10

Peer 10.10.2.2 ebgp-max-hop

10. Configure AR5

Bgp 64512

Route-id 1.1.1.1

Network 192.168.100.1 255.255.255.0

11. View the configuration in AR5 AR6 AR7

Dis bgp routeing-table

AR5:

AR6:

AR7:

12 configure AR7

Bgp 64513rou

Route-id 3.3.3.3

Import-route direct

13. View the configuration in AR5 AR6 AR7

Dis bgp routeing-table

AR5

AR6

AR7

14. Configure the interconnection between loopback0 of AR5 and loopback0 of AR7

AR5:

Ping-a 192.168.100.1 192.168.200.3

AR7:

Ping-a 192.168.200.3 192.168.100.1

-

Two:

Physical links can also be configured

Train of thought

1. Configure AR5 0 port ip:192.168.12.1 24

Create loopback 0 ip:192.168.100.1 24

two。 Configure AR6 0 port ip:192.168.12.2 24

1 port ip:192.168.23.1 24

3. Configure AR7 0 port ip:192.168.23.2 24

Create loopback 0 ip:192.168.200.3 24

4. Configure AR5 OSPF

Ospf route-id 1.1.1.1

Area 0

Network 192.168.12.0 0.0.0.255

5. Configure AR6 OSPF

Ospf route-id 2.2.2.2

Area 0

Network 192.168.12.0 0.0.0.255

Network 192.168.23.0 0.0.0.255

6. Configure AR7 OSPF

Ospf route-id 3.3.3.3

Area 0

Network 192.168.23.0 0.0.0.255

At this time, the ports can communicate with each other.

7. Configure AR5 BGP

Bgp 64512

Route-id 1.1.1.1

Confederation id 200

Peer 192.168.12.2 as-number 64512

8. Configure AR6 BGP

Bgp 64512

Route-id 2.2.2.2

Confederation id 200

Confederation peer-as 64513

Peer 192.168.23.2 as-number 64513

Peer 10.10.3.3 ebgp-max-hop

Peer192.168.12.1 as-number 65412

Peer 192.168.12.1connect-interface loopback 10

9. Configure AR7 BGP

Bgp 64513

Route-id 3.3.3.3

Confederation id 200

Confederation peer-as 64512

Peer 192.168.23.1 as-number 64512

Peer 10.10.2.2 ebgp-max-hop

10. Configure AR5

Bgp 64512

Route-id 1.1.1.1

Network 192.168.100.1 255.255.255.0

11. View the configuration in AR5 AR6 AR7

Dis bgp routeing-table

12 configure AR7

Bgp 64513rou

Route-id 3.3.3.3

Import-route direct

13. View the configuration in AR5 AR6 AR7

Dis bgp routeing-table

14. Configure the interconnection between loopback0 of AR5 and loopback0 of AR7

AR5:

Ping-a 192.168.100.1 192.168.200.3

AR7:

Ping-a 192.168.200.3 192.168.100.1

If there is no loopback address, there is no directly connected route, so there is no need to consider "update detection mechanism".

Command:

Peer neighbor ip connect-interface loopbacck x

"directly connected detection mechanism" must be considered for directly connected routes.

Command:

Peer neighbor ip ebgp-max-hop

=

Key points:

Dynamically learn routing entries between routers to form a routing table

IGP: calculate the shortest, loop-free forwarding path to the destination network at the fastest speed

-DV

RIP

IGRP

EIGRP

-LS

ISIS

OSPF

EGP: stable and reliable transmission of a large number of routes between different enterprises, and routing can be realized.

Flexible control and guarantee no loop

-BGP:border gateway protocol, Border Gateway Protocol

Used to connect different enterprises or organizational structures

Prefix/mask type priority cost next-hop, interface

In the database-- (priority/cost)-- > in the routing table

-match packet:

Longest matching principle

Money money home

Priority: indicates the stability of the route, the smaller the value, the better; 0-255

Metric (metric): indicates the distance to a destination network, as small as possible

OSPF:

1. Neighbor table

2. Database

3. Routing table

-hello: unreliable transmission mode

-DBD: implicit confirmation, confirmed through the sequence number field in the DBD message

-LSU: explicitly confirm that each LSU sent will return a LSAck

-LSR: explicitly confirm that each LSR sent will return a LSAck

-LSAck: only acknowledges other messages, but the transmission itself is unreliable

L2+L3+OSPF

BGP:

L2+L3+TCP+BGP-tcp 179

L2+L3+UDP+RIP-udp 520

L2+L3+OSFP-protocol-id: 89, TCP/IP routing Technology Volume 1, OSPF 2 | OSPF Design and implementation | OSPF Command Manual

L2+L3+EIGRP-protocol-id:88

L2+ISIS

About switching:

BCMSN chm/pdf

How BGP works:

1. Neighbor table: display bgp peer

2. Database: display bgp routing-table

3. Routing table

Bgp {as} # as is divided into public and private, [64512 Murray 65535]

Peer {ip-address} as-number {} of the other device

BGP neighbor establishment:

-Internal neighbor

R1

Bgp 64512 # the BGP AS number that the device is running locally

Router-id 1.1.1.1

Peer 192.168.12.2 as-number 64512 # the AS number to which the neighbor router belongs

R2

Bgp 64512

Router-id 2.2.2.2

Peer 192.168.12.1 as-number 64512

Display bgp peer # View the BGP neighbor table on the device

Local-as

Local-router-id

Number of peers

Peer v as msgrcvd msgsent outq up/down state prefrvcd

R1:

Bgp 64512

Peer 10.10.2.2 as-number 64512

# R1 initiates a link to TCP 179 to 10.10.2.2

# 10.10.2.2 must be located in AS 64512

Or

10.10.2.2 reply message, which must belong to as 64512

# when the other party returns a packet, the source IP address used must be 10.10.2.2

Otherwise it will not be accepted (this is the "update source detection mechanism")

In order to solve the "update source detection mechanism" faced by "non-directly connected ports when establishing neighbors"

So when we send a BGP link request, we change the source IP address of the message:

For example:

Bgp 64512

Peer 10.10.2.2 connect-interface loopback 0

It is strongly recommended:

When establishing a BGP neighbor relationship on a non-directly connected port, the Peer commands on both sides are used

This parameter

-

Non-directly connected IBGP neighbor relationships are established:

1. Configure IP

2. Configure IGP

3. Configure BGP

Mechanisms to consider when establishing external BGP neighbors:

1. Update source detection mechanism-- the same as IBGP neighbors

2. Directly connected detection mechanism

# when will the mechanism be checked?

Check only when the EBGP is established and the TTL of the BGP message sent is 1

# what is the definition of this mechanism

When going to a neighbor address, you must use a "directly connected route"

If not, the "directly connected detection mechanism" is not satisfied, so EBGP neighbors cannot be established.

In the face of the "non-directly connected EBGP neighbor relationship" established for the stability of the link, we need to modify the EBGP

The TTL value of the message is not "1". Because, once it is not 1, it will not care about the mechanism.

Bgp 64513

Peere 10.10.2.2 ebgp-max-hop [255]

=

IBGP neighbor anti-ring mechanism:

-IBGP horizontal segmentation

Refers to routes received from internal neighbor routers and will not be sent to other internal neighbors again

Solution:

-IBGP full interconnection

-BGP Alliance

Big AS: large AS is used in messages sent between external neighbors

Little AS: it must be used among the "inner neighbors" within the alliance.

Also used between special external neighbors between "federate member AS" within the alliance

R1:

Bgp 64512

The number of the confederation id 200 # BGP Alliance, which represents the Big AS

Peer 10.10.2.2 as-number 64512

Peer 10.10.2.2 connect-interface loopback 10

R2:

Bgp 64512

Confederation id 200

Confederation peer-as 64513

Peer 10.10.1.1 as-number 64512 # is an internal neighbor with R1, so use a small AS

Peer 10.10.1.1 connect-interface loopback 0

Peer 10.10.3.3 as-number 64513 # Special external neighbor within the Alliance, using Little AS

Peer 10.10.3.3 connect-interface loopback 0

Peer 10.10.3.3 ebgp-max-hop

Peer 192.168.24.4 as-number 400 # large AS is used to establish a neighbor with R4

R3:

Bgp 64513

Confederation id 200

Confederation peer-as 64512

Peer 10.10.2.2 as-number 64512

Peer 10.10.2.2 connect-interface loopback 10

Peer 10.10.2.2 ebgp-max-hop

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