{"draft":"draft-ietf-tsvwg-rfc6040update-shim-23","doc_id":"RFC9601","title":"Propagating Explicit Congestion Notification across IP Tunnel Headers Separated by a Shim","authors":["B. Briscoe"],"format":["HTML","TEXT","PDF","XML"],"page_count":"19","pub_status":"PROPOSED STANDARD","status":"PROPOSED STANDARD","source":"Transport and Services Working Group","abstract":"RFC 6040 on \"Tunnelling of Explicit Congestion Notification\" made the\r\nrules for propagation of Explicit Congestion Notification (ECN)\r\nconsistent for all forms of IP-in-IP tunnel. This specification\r\nupdates RFC 6040 to clarify that its scope includes tunnels where two\r\nIP headers are separated by at least one shim header that is not\r\nsufficient on its own for wide-area packet forwarding. It surveys\r\nwidely deployed IP tunnelling protocols that use such shim headers\r\nand updates the specifications of those that do not mention ECN\r\npropagation (including RFCs 2661, 3931, 2784, 4380 and 7450, which\r\nspecify L2TPv2, L2TPv3, Generic Routing Encapsulation (GRE), Teredo,\r\nand Automatic Multicast Tunneling (AMT), respectively). This\r\nspecification also updates RFC 6040 with configuration requirements\r\nneeded to make any legacy tunnel ingress safe.","pub_date":"August 2024","keywords":["Congestion Control and Management","Congestion Notification","Information Security","Tunnelling","Encapsulation & Decapsulation","Protocol","ECN","Layering"],"obsoletes":[],"obsoleted_by":[],"updates":["RFC2661","RFC2784","RFC3931","RFC4380","RFC6040","RFC7450"],"updated_by":[],"see_also":[],"doi":"10.17487\/RFC9601","errata_url":null}