Propagating Explicit Congestion Notification across IP Tunnel Headers Separated by a Shim
RFC 9601

Received changes through RFC Editor sync (created document RFC 9601, created became rfc relationship between draft-ietf-tsvwg-rfc6040update-shim and RFC 9601, set title to 'Propagating Explicit Congestion Notification across IP Tunnel Headers Separated by a Shim', set abstract to 'RFC 6040 on "Tunnelling of Explicit Congestion Notification" made the rules for propagation of Explicit Congestion Notification (ECN) consistent for all forms of IP-in-IP tunnel.  This specification updates RFC 6040 to clarify that its scope includes tunnels where two IP headers are separated by at least one shim header that is not sufficient on its own for wide-area packet forwarding.  It surveys widely deployed IP tunnelling protocols that use such shim headers and updates the specifications of those that do not mention ECN propagation (including RFCs 2661, 3931, 2784, 4380 and 7450, which specify L2TPv2, L2TPv3, Generic Routing Encapsulation (GRE), Teredo, and Automatic Multicast Tunneling (AMT), respectively).  This specification also updates RFC 6040 with configuration requirements needed to make any legacy tunnel ingress safe.', set pages to 19, set standardization level to Proposed Standard, added RFC published event at 2024-08-30, created updates relation between RFC 9601 and RFC 2661, created updates relation between RFC 9601 and RFC 2784, created updates relation between RFC 9601 and RFC 3931, created updates relation between RFC 9601 and RFC 4380, created updates relation between RFC 9601 and RFC 6040, created updates relation between RFC 9601 and RFC 7450)