This content originally appeared on DEV Community and was authored by Abdulrazzaq Aminu
While managing an enterprise edge router connected to both a transit provider and a local Internet Exchange Point (IXP), I observed that return traffic destined for IXP-advertised prefixes was instead arriving via the transit provider. This resulted in underutilization of the IXP link and unnecessary bandwidth consumption on the more expensive transit path.
To address this, I implemented AS_PATH prepending by appending our ASN three times to outbound route advertisements sent to the transit provider. This made our routes appear less preferred, thereby influencing external networks to return traffic via the IXP instead. This optimization ensured more efficient use of the IXP link and reduced load on the transit connection.
This content originally appeared on DEV Community and was authored by Abdulrazzaq Aminu