Autonomous Systems Analysis with BGP

BGP routing configuration between autonomous systems using Mikrotik routers, simulating a multi-AS interconnected network.

Topology

• Router A (AS 65000) ↔ Router B (AS 100) ↔ Router C (AS 100)
• Router D (AS 100) ↔ Router E (AS 100) ↔ Router F (AS 65000)
• Goal: Router A communicates with Router F through the intermediate AS network.

Router A Configuration (AS 65000)

# Configure interface IPs:
ip address add address=[ip/mask] interface=[iface]

# Create bridge interface:
interface bridge add name=bridge1

# Configure BGP:
routing bgp instance set default as=65000 redistribute-connected=yes

# Add BGP peers:
routing bgp peer add remote-address=10.1.1.2 remote-as=100 allow-as-in=1
routing bgp peer add remote-address=10.1.1.6 remote-as=100 allow-as-in=1

Routers B, C, D, E, F

Same structure: configure interface IPs and add BGP peers to each neighbouring router according to the topology.

Verification

# From Router A — ping Router F:
ping 10.3.3.2

# View full routing table:
ip route print detail

# From Router F — verify reachability:
ip route print

Key Concepts