Multi-homed BGP peering and ISP routing

Multi-homed BGP operation with IPT upstreams, external CDNs, local CDNs, peerings to external customers, routing policies, prefix filters, and session monitoring.

Key metrics

2 IP transit (IPT) upstreams
2 external CDNs + 3 local CDNs
2 peerings delivering CDN traffic to external customers
RPKI/IRR filters in place
BGP session monitoring with alerts

Key facts

Scope: operation of BGP sessions with IPT transit, external CDNs, local CDNs, and peerings to external customers.
Routing: Local Preference policies, AS Path prepend, and BGP communities to prioritize transit, CDNs, and traffic delivery.
Security: IRR- and RPKI-based prefix filters to prevent hijacking and leaks.
Goal: high availability, transit optimization, better content experience, and operational continuity.

Stack

BGP
RPKI
IRR
CDNs
MikroTik
Juniper

Sanitized BGP/CDN flow diagram

IPT upstreams
BGP policies
Local/external CDNs
External customers

Logical view without ASNs, prefixes, IPs, or third-party names.

Anonymized Grafana panel with BGP peering, CDN, and ISP traffic metrics — Anonymized Grafana: monitoring of sessions, traffic, and operational status of BGP/CDN peerings.

Context

The ISP already ran with transit redundancy, but the network kept growing until it reached two IPT upstreams, two external CDNs, three local CDNs, and two peerings delivering traffic to external customers so they could reach those local CDNs. That growth demanded consistent BGP policies for availability, route control, content prioritization, and session monitoring.

Actions

Operated and evolved a multi-homed BGP design with IPT upstreams, external CDNs, local CDNs, and peerings to third parties.
Implemented routing policies: Local Preference to prioritize transit and content, AS Path prepend for balancing, and BGP communities for traffic control.
Filtered inbound and outbound prefixes based on IRR databases and RPKI validation.
Monitored BGP sessions with alerts for critical upstreams, CDNs, and peerings.

Results

Consolidated BGP topology with 2 IPT upstreams, 2 external CDNs, 3 local CDNs, and 2 peerings to external customers.
Better transit and CDN utilization through preference, balancing, and traffic-control policies.
Active RPKI validation: mitigated prefix hijacking and route leak risks.
Local CDN traffic delivered to external customers through controlled peerings.