LON2 Network Refresh#

Jan Kayser (LINX)

• Why: The rarest commodity at an operator conference — a public postmortem-flavored account of refreshing a production fabric with live members on it. LINX ran the world's first disaggregated EVPN IXP LAN (2018) with hardware and software from different vendors, so their refresh story is a directly transferable lesson in multi-vendor fabric migration risk.
• What: How LINX refreshed LON2, their second-biggest London LAN, while roughly a third of LINX membership remained connected — and the title's pointed "or was there?" promises the parts that went wrong, not just the happy path (from abstract only).
• How: Per the abstract: an in-house, redundant dual-LAN design (LON1/LON2 since 2002, deliberately avoiding a single point of failure for UK connectivity), EVPN control plane on disaggregated hardware/software, migrated around end-of-life equipment. The talk is short (10 min + Q&A); expect the migration sequencing and failure detail rather than deep architecture.
• Where applicable: The dual-LAN IXP resilience model is LINX-specific, but the underlying problem — refresh an EVPN fabric in place without evacuating tenants — is universal for anyone running a DC or exchange fabric. Watch for what the multi-vendor sourcing actually cost them operationally.