BGP .

BGP:
BGP
, IP-. , .
AS . AS , , , -.
, AS- 16- , 65 536 AS. : 64512-65535
.
, . , 32- .
, , Border Gateway Protocol . . .
, . , , .
BGP BGP . ( ) 1. .

1: BGP
ATL1(config)#router bgp 200 ATL1( config-router)#neiqhbor 10.30.30.5 remote-as 200 ATL1( config-router)#neiqhbor 10.30.30.5 update- source lo0 ATL1( config= router)#neiqhbor 10.30 .30.5 password S34Dfr112s1WP ATL1(config-router)#neiqhbor 10.40.40.4 remote-as 200 ATL1( config-router)#neiqhbor 10.40.40 .4 update- source lo0 ATL1(config-router)#neiqhbor 10.40.40.4 password S34Dfr112s1WP
, . . . 2 , BGP.
2: BGP
ATL2 (config)#router bgp 200 ATL2 (config-router)#neighbor MYPEERGR1 peer-group ATL2 (config-router)#neighbor MYPEERGR1 remote-as 200 ATL2 (config-router)#neighbor MYPEERG1l update-source lo0 ATL2(config-router)#neighbor MYPEERGRl next-hop-self ATL2 (config-router)#neighbor 10.40.40 .4 peer-group MYPEERGR1 ATL2 (config-router)#neighbor 10.50.50 .5 peer-group MYPEERGR1
, , , , . ? . , .
( ) . ( iOS 12 ) . - .
, , . , . , .
, , . , , .
, , , . , . , , . , BGP.
, . . , : . , , .
, , . , , , . , timers
, remote-as
.
, update source
. eBGP multihop. , . , . template peer-session
, . , . remote-as / update source
. , exit-peer-session
, . 3 .
3: BGP
ATL2#conf t Enter configuration commands, one per line. End with CNTL/Z. ATL2 (config)#router bgp 200 ATL2 (config-router)#template peer- session MYNAME ATL2 (config-router-stmp)#inherit peer- session MYOTHERNAME ATL2 (config- router-stmp )#remote-as 200 ATL2(config-router-stmp )#password MySecrectPass123 ATL2 (config-router-stmp )#exit-peer-session ATL2 (config-router)#neiqhbor 10.30.30 .10 inherit peer-session MYNAME ATL2 (config-router)#end ATL2#
neighbor . , . .
, , , IP-, , . , , , .
, , . , , , BGP, , , , , .
4 BGP.
4: BGP
ATL2#conf t Enter configuration commands, one per line. End with CNTL/Z. ATL2 (config)#router bgp 200 ATL2(config-router)#template peer-policy MYPOLICYNAME ATL2 (config-router-ptmp )#next-hop-self ATL2 (config-router-ptmp )#route-map MYMAP out ATL2 (config-router-ptmp )#allowas-in ATL2 (config-router-ptmp )#exit-peer-policy ATL2 (config-router)#neighbor 10.40.40.10 remote-as 200 ATL2 (config-router)#neighbor 10.40.40.10 inherit peer-policy MYNAME ATL2 (config-router)#end ATL2#
, , , , . , .
, , . .
, , , .
(split-horizon rule) IBGP, , IBGP. router reflector.
. 1: router reflector

router reflector , router reflector (R3). route reflector R4, R5 R6. IBGP R3 . 5 router reflector. , router reflector.
5: BGP ROUTE REFLECTOR
R3#configure terminal Enter configuration commands, one per line. End with CNTL/Z. R3 (config)#router bgp 200 R3 (config-router)#neighbor 10.50.50.10 remote -as 200 R3 (config-router)#neighbor 10.50.50.10 route-reflector-client R3 (config-router)#end R3#
Route reflector (ID) , , route reflector. Cisco . 32- , BGP route reflector.
Route reflector , IBGP. , Route reflector (, R4), R3 (R5 R6), (R1 R2). , IBGP , .
, Route reflector (R1)? Route reflector Route reflector (R4, R5 R6). R3 IBGP, IBGP Route reflector (R2).
, R1 R2 IBGP. , R2 Route reflector R3.
, IBGP- EBGP. . , , Route reflector. , , . . 2 .
2:

AS 100. . , .
, eBGP, EBGP ? , . , , EBGP. , AS 100.
AS, EBGP . IBGP, EBGP? . , .
- . AS_confed_sequence
AS_confed_set
.
6 BGP.
R3#configure terminal Enter configuration commands, one per line. End with CNTL/Z. R3 (config)#router bgp 65501 R3(config-router)#bgp confederation identifier 100 R3 (config-router)#bgp confederation peers 65502 R3 (config-router)#neighbor 10 .20.20.1 remote-as 65502 R3 (config-router)#end R3#
. , , (community). , , . 32- ( ), , .
, AS. , . , , BGP.
. :
- Decimal - 0 to 4294967200 ( )
- Hexadecimal 0x0 to 0xffffffa0 ( )
:
- AA:NN
AA
- 16- , AS, 16- , AS. , AS 100 100:101, 101- , .
. :
- No-export - AS. , AS. ( AS) .
- Local-AS - AS
- No-advertise -
.
, . 64- ! TYPE:VALUE. :
- 65535:4294967295
, , route maps. 7 . , . BGP . , .
7: BGP
R3#configure terminal Enter configuration commands, one per line. End with CNTL/Z. R3(config)#ip prefix-list MYLIST permit 172.16.0.0/16 le 32 R3(config)#route-map SETCOMM permit 10 R3(config-route-map)#match ip address prefix-list MYLIST R3(config-route-map)#set community no-export R3(config-route-map)#route-map SETCOMM permit 20 R3(config)#router bgp 100 R3(config-router)#neighbor 10.20.20.1 route-map SETCOMM out R3 (config-router)#neighbor 10.20.20.1 send-community R3(config-router)#end R3#