Onnowpurbo: Created page with "thumb Sambungan ISP1: eth0 --> ISP3 eth0 eth1 --> ISP2 eth1 ISP2 eth0 --> ISP3 eth1 eth1 --> ISP1 eth1 ISP3 eth0 -->..."

2026-05-20T11:32:10Z

Created page with "center|400px|thumb Sambungan ISP1: eth0 --> ISP3 eth0 eth1 --> ISP2 eth1 ISP2 eth0 --> ISP3 eth1 eth1 --> ISP1 eth1 ISP3 eth0 -->..."

New page

[[File:Bgp-multihoming.png|center|400px|thumb]]

Sambungan

ISP1:
eth0 --> ISP3 eth0
eth1 --> ISP2 eth1

ISP2
eth0 --> ISP3 eth1
eth1 --> ISP1 eth1

ISP3
eth0 --> ISP1 eth0
eth1 --> ISP2 eth0

Ada tiga (3) ISP

ISP1:
IP 192.168.1.1/24 menuju ISP3
IP 192.168.3.1/24 menuju ISP2
AS 10
IP 10.100.100.0/24
IP 10.100.200.0/24

ISP2
IP 192.168.2.1/24 - menuju ISP3
IP 192.168.3.2/24 - menuju ISP1
AS 20
IP 10.10.10.0/24
IP 10.10.20.0/24

ISP3 (kita)
IP 192.168.1.2/24 - menuju ISP1
IP 192.168.2.2/24 - menuju ISP2
AS 30
IP 10.1.1.0/24
IP 10.1.2.0/24

Berikut konfigurasi **MikroTik RouterOS v7** yang rapi untuk **ISP1, ISP2, ISP3** sesuai topologi pada file: ISP1 AS10, ISP2 AS20, ISP3 AS30; masing-masing punya dua koneksi BGP dan dua network lokal.

Prinsip filter sederhana:

* **Input filter:** `accept;` semua route dari peer.
* **Output filter:** hanya advertise network lokal sendiri.
* **Tidak perlu blackhole route** karena network lokal sudah ada sebagai *connected route* dari `ether3` dan `ether4`.

==ISP1 — AS 10==

# =========================
# ISP1 - RouterOS v7
# AS 10
# =========================

# IP address
/ip address
add interface=ether1 address=192.168.1.1/24 comment="to ISP3"
add interface=ether2 address=192.168.3.1/24 comment="to ISP2"
add interface=ether3 address=10.100.100.1/24 comment="LAN 10.100.100.0/24"
add interface=ether4 address=10.100.200.1/24 comment="LAN 10.100.200.0/24"

# BGP local AS
/routing bgp template
set default as=10

# BGP connections
/routing bgp connection
add name=toISP3 remote.address=192.168.1.2 remote.as=30 local.role=ebgp templates=default
add name=toISP2 remote.address=192.168.3.2 remote.as=20 local.role=ebgp templates=default

# Advertised local networks
/ip firewall address-list
add list=bgp-networks address=10.100.100.0/24
add list=bgp-networks address=10.100.200.0/24

# Simple input filters: accept all received routes
/routing filter rule
add chain=isp2-in rule="accept;"
add chain=isp3-in rule="accept;"

# Simple output filters: advertise only ISP1 local prefixes
/routing filter rule
add chain=isp2-out rule="if (dst in 10.100.100.0/24) { accept; }"
add chain=isp2-out rule="if (dst in 10.100.200.0/24) { accept; }"
add chain=isp2-out rule="reject;"

add chain=isp3-out rule="if (dst in 10.100.100.0/24) { accept; }"
add chain=isp3-out rule="if (dst in 10.100.200.0/24) { accept; }"
add chain=isp3-out rule="reject;"

# Apply filters and advertised networks
/routing bgp connection
set toISP2 output.network=bgp-networks input.filter=isp2-in output.filter-chain=isp2-out
set toISP3 output.network=bgp-networks input.filter=isp3-in output.filter-chain=isp3-out

==ISP2 — AS 20==

# =========================
# ISP2 - RouterOS v7
# AS 20
# =========================

# IP address
/ip address
add interface=ether1 address=192.168.2.1/24 comment="to ISP3"
add interface=ether2 address=192.168.3.2/24 comment="to ISP1"
add interface=ether3 address=10.10.10.1/24 comment="LAN 10.10.10.0/24"
add interface=ether4 address=10.10.20.1/24 comment="LAN 10.10.20.0/24"

# BGP local AS
/routing bgp template
set default as=20

# BGP connections
/routing bgp connection
add name=toISP1 remote.address=192.168.3.1 remote.as=10 local.role=ebgp templates=default
add name=toISP3 remote.address=192.168.2.2 remote.as=30 local.role=ebgp templates=default

# Advertised local networks
/ip firewall address-list
add list=bgp-networks address=10.10.10.0/24
add list=bgp-networks address=10.10.20.0/24

# Simple input filters: accept all received routes
/routing filter rule
add chain=isp1-in rule="accept;"
add chain=isp3-in rule="accept;"

# Simple output filters: advertise only ISP2 local prefixes
/routing filter rule
add chain=isp1-out rule="if (dst in 10.10.10.0/24) { accept; }"
add chain=isp1-out rule="if (dst in 10.10.20.0/24) { accept; }"
add chain=isp1-out rule="reject;"

add chain=isp3-out rule="if (dst in 10.10.10.0/24) { accept; }"
add chain=isp3-out rule="if (dst in 10.10.20.0/24) { accept; }"
add chain=isp3-out rule="reject;"

# Apply filters and advertised networks
/routing bgp connection
set toISP1 output.network=bgp-networks input.filter=isp1-in output.filter-chain=isp1-out
set toISP3 output.network=bgp-networks input.filter=isp3-in output.filter-chain=isp3-out

==ISP3 — AS 30==

# =========================
# ISP3 - RouterOS v7
# AS 30
# =========================

# IP address
/ip address
add interface=ether1 address=192.168.1.2/24 comment="to ISP1"
add interface=ether2 address=192.168.2.2/24 comment="to ISP2"
add interface=ether3 address=10.1.1.1/24 comment="LAN 10.1.1.0/24"
add interface=ether4 address=10.1.2.1/24 comment="LAN 10.1.2.0/24"

# BGP local AS
/routing bgp template
set default as=30

# BGP connections
/routing bgp connection
add name=toISP1 remote.address=192.168.1.1 remote.as=10 local.role=ebgp templates=default
add name=toISP2 remote.address=192.168.2.1 remote.as=20 local.role=ebgp templates=default

# Advertised local networks
/ip firewall address-list
add list=bgp-networks address=10.1.1.0/24
add list=bgp-networks address=10.1.2.0/24

# Simple input filters: accept all received routes
/routing filter rule
add chain=isp1-in rule="accept;"
add chain=isp2-in rule="accept;"

# Simple output filters: advertise only ISP3 local prefixes
/routing filter rule
add chain=isp1-out rule="if (dst in 10.1.1.0/24) { accept; }"
add chain=isp1-out rule="if (dst in 10.1.2.0/24) { accept; }"
add chain=isp1-out rule="reject;"

add chain=isp2-out rule="if (dst in 10.1.1.0/24) { accept; }"
add chain=isp2-out rule="if (dst in 10.1.2.0/24) { accept; }"
add chain=isp2-out rule="reject;"

# Apply filters and advertised networks
/routing bgp connection
set toISP1 output.network=bgp-networks input.filter=isp1-in output.filter-chain=isp1-out
set toISP2 output.network=bgp-networks input.filter=isp2-in output.filter-chain=isp2-out

==Command pengecekan==

Jalankan di masing-masing router:

/routing bgp session print

Harus muncul flag:

E

Artinya **established**.

Cek route BGP yang diterima:

/ip route print where bgp

atau:

/routing route print where bgp

Cek filter:

/routing filter rule print

Cek advertised address-list:

/ip firewall address-list print where list=bgp-networks

==Catatan penting==

Kalau muncul:

failure: already have such address

artinya IP tersebut sudah ada. Tidak perlu ditambahkan ulang.

Kalau muncul:

failure: already have such entry

artinya address-list sudah ada. Tidak perlu ditambahkan ulang.

Kalau muncul:

no such item

biasanya karena nama connection salah. Gunakan:

/routing bgp connection print

Lalu pastikan perintah `set` memakai nama yang benar, misalnya:

set toISP1 ...
set toISP2 ...
set toISP3 ...

bukan:

set isp1 ...
set isp2 ...
set isp3 ...

Mikrotik 7: BGP Sedehana - Revision history

Onnowpurbo: Created page with "thumb Sambungan ISP1: eth0 --> ISP3 eth0 eth1 --> ISP2 eth1 ISP2 eth0 --> ISP3 eth1 eth1 --> ISP1 eth1 ISP3 eth0 -->..."