Apa itu BGP?
Border Gateway Protocol (BGP) adalah protokol routing yang menjadi tulang punggung komunikasi di Internet. BGP bertugas mengelola lalu lintas antar jaringan atau Autonomous System (AS), dengan memilih jalur terbaik untuk mengirimkan data ke tujuan tertentu. Dengan BGP, router dapat bertukar informasi tentang rute mana yang lebih efisien dan andal untuk mencapai jaringan lain, memungkinkan Internet berfungsi secara global.
Apa itu Autonomous System (AS)?
Autonomous System (AS) adalah sekumpulan jaringan yang dioperasikan di bawah satu administrasi atau penyedia layanan internet (ISP). Setiap AS memiliki Nomor AS (ASN) yang unik, yang berfungsi sebagai identitas di Internet. ASN ini memungkinkan jaringan saling terhubung dan berkomunikasi secara efektif, serta mempermudah pengelolaan rute di antara berbagai organisasi yang mengelola infrastruktur jaringan.
¶ Syntax
Berikut adallah syntax command yang digunakan dalam konfigurasi BGP (Border Gateway Protocol).
¶ Basic commands
| Command | Description |
|---|---|
router bgp <AS_number>* |
Semasuki BGP Configuration Mode: |
.neighbor <IP_address> remote-as <AS_number>* |
Tentukan AS Tetangga (Remote Peer) |
bgp router-id <IP_address> |
Tentukan Local BGP Router ID, Jika tidak akan terpilih otomatis |
network <network_IP> mask <subnet_mask> |
Menngadvertise sebuah Network |
¶ Basic commands
| Command | Description |
|---|---|
show ip bgp neighbors |
Show BGP Neighbors |
.show ip bgp summary |
Show BGP Summary |
show ip bgp |
show ip route bgp |
¶ Topology
¶ Configuration
¶ Preconfiguration
interface FastEthernet0/0
ip address 192.168.1.1 255.255.255.0
no shutdown
interface Serial1/0
ip address 10.0.0.1 255.255.255.252
clock rate 2000000
no shutdown
interface FastEthernet0/0
ip address 192.168.2.1 255.255.255.0
no shutdown
!
interface Serial1/0
ip address 10.0.0.2 255.255.255.252
no shutdown
interface FastEthernet0/0
ip address 192.168.1.2 255.255.255.0
no shutdown
interface FastEthernet0/0
ip address 192.168.2.2 255.255.255.0
no shutdown
¶
¶ BGP Configuration
- Configurasi BGP Pada Router1
router bgp 100
neighbor 10.0.0.2 remote-as 200
network 192.168.1.0 mask 255.255.255.0
- Configurasi BGP Pada Router2
router bgp 200
neighbor 10.0.0.1 remote-as 100
network 192.168.2.0 mask 255.255.255.0
¶ log
R1#show ip bgp neighbors
BGP neighbor is 10.0.0.2, remote AS 200, external link
BGP version 4, remote router ID 192.168.2.1
BGP state = Established, up for 00:00:36
Last read 00:00:06, last write 00:00:06, hold time is 180, keepalive interval is 60 seconds
Neighbor capabilities:
Route refresh: advertised and received(old & new)
Address family IPv4 Unicast: advertised and received
Message statistics:
InQ depth is 0
OutQ depth is 0
Sent Rcvd
Opens: 1 1
Notifications: 0 0
Updates: 1 1
Keepalives: 2 2
Route Refresh: 0 0
Total: 4 4
Default minimum time between advertisement runs is 30 seconds
For address family: IPv4 Unicast
BGP table version 3, neighbor version 3/0
Output queue size : 0
Index 1, Offset 0, Mask 0x2
1 update-group member
Sent Rcvd
Prefix activity: ---- ----
Prefixes Current: 1 1 (Consumes 52 bytes)
Prefixes Total: 1 1
Implicit Withdraw: 0 0
Explicit Withdraw: 0 0
Used as bestpath: n/a 1
Used as multipath: n/a 0
Outbound Inbound
Local Policy Denied Prefixes: -------- -------
Bestpath from this peer: 1 n/a
Total: 1 0
Number of NLRIs in the update sent: max 1, min 1
Connections established 1; dropped 0
Last reset never
Connection state is ESTAB, I/O status: 1, unread input bytes: 0
Connection is ECN Disabled, Mininum incoming TTL 0, Outgoing TTL 1
Local host: 10.0.0.1, Local port: 59207
Foreign host: 10.0.0.2, Foreign port: 179
Enqueued packets for retransmit: 0, input: 0 mis-ordered: 0 (0 bytes)
Event Timers (current time is 0x6A9880):
Timer Starts Wakeups Next
Retrans 4 0 0x0
TimeWait 0 0 0x0
AckHold 3 1 0x0
SendWnd 0 0 0x0
KeepAlive 0 0 0x0
GiveUp 0 0 0x0
PmtuAger 0 0 0x0
DeadWait 0 0 0x0
iss: 3940290831 snduna: 3940290967 sndnxt: 3940290967 sndwnd: 16249
irs: 2763685506 rcvnxt: 2763685642 rcvwnd: 16249 delrcvwnd: 135
SRTT: 124 ms, RTTO: 1405 ms, RTV: 1281 ms, KRTT: 0 ms
minRTT: 20 ms, maxRTT: 300 ms, ACK hold: 200 ms
Flags: active open, nagle
IP Precedence value : 6
Datagrams (max data segment is 1460 bytes):
Rcvd: 5 (out of order: 0), with data: 3, total data bytes: 135
Sent: 7 (retransmit: 0, fastretransmit: 0, partialack: 0, Second Congestion: 0), with data: 4, total data bytes: 135
R1#show ip bgp summary
BGP router identifier 192.168.1.1, local AS number 100
BGP table version is 3, main routing table version 3
2 network entries using 234 bytes of memory
2 path entries using 104 bytes of memory
3/2 BGP path/bestpath attribute entries using 372 bytes of memory
1 BGP AS-PATH entries using 24 bytes of memory
0 BGP route-map cache entries using 0 bytes of memory
0 BGP filter-list cache entries using 0 bytes of memory
BGP using 734 total bytes of memory
BGP activity 2/0 prefixes, 2/0 paths, scan interval 60 secs
Neighbor V AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down State/PfxRcd
10.0.0.2 4 200 6 6 3 0 0 00:02:27 1
R1#show ip route
Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP
D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
E1 - OSPF external type 1, E2 - OSPF external type 2
i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
ia - IS-IS inter area, * - candidate default, U - per-user static route
o - ODR, P - periodic downloaded static route
Gateway of last resort is not set
10.0.0.0/30 is subnetted, 1 subnets
C 10.0.0.0 is directly connected, Serial1/0
C 192.168.1.0/24 is directly connected, FastEthernet0/0
B 192.168.2.0/24 [20/0] via 10.0.0.2, 00:02:33