Iljitsch van Beijnum has been working with BGP in ISP and end-user networks since 1996. He has configured the protocol on single-router networks; networks with several hundred Ciscos ranging from the slowest to the fastest available; and multivendor environments with BGP running on Cisco and Juniper routers, Extreme switches, and FreeBSD hosts running GNU Zebra (Quagga wasn't yet invented then). These days he's also into IPv6.