From mboxrd@z Thu Jan 1 00:00:00 1970 From: Roopa Prabhu Subject: Re: [PATCH net-next v3 0/2] mpls: allow TTL propagation to/from IP packets to be configured Date: Mon, 13 Mar 2017 13:28:59 -0700 Message-ID: <58C7010B.2010609@cumulusnetworks.com> References: <1488933990-14490-1-git-send-email-rshearma@brocade.com> <1489178605-30027-1-git-send-email-rshearma@brocade.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: davem@davemloft.net, netdev@vger.kernel.org, "Eric W. Biederman" , David Ahern To: Robert Shearman Return-path: Received: from mail-pg0-f49.google.com ([74.125.83.49]:34282 "EHLO mail-pg0-f49.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752994AbdCMU3C (ORCPT ); Mon, 13 Mar 2017 16:29:02 -0400 Received: by mail-pg0-f49.google.com with SMTP id 77so69173583pgc.1 for ; Mon, 13 Mar 2017 13:29:01 -0700 (PDT) In-Reply-To: <1489178605-30027-1-git-send-email-rshearma@brocade.com> Sender: netdev-owner@vger.kernel.org List-ID: On 3/10/17, 12:43 PM, Robert Shearman wrote: > It is sometimes desirable to present an MPLS transport network as a > single hop to traffic transiting it because it prevents confusion when > diagnosing failures. An example of where confusion can be generated is > when addresses used in the provider network overlap with addresses in > the overlay network and the addresses get exposed through ICMP errors > generated as packets transit the provider network. > > In addition, RFC 3443 defines two methods of deriving TTL for an > outgoing packet: Uniform Model where the TTL is propagated to/from the > MPLS header and both Pipe Models and Short Pipe Models (with and > without PHP) where the TTL is not propagated to/from the MPLS header. > > Changes in v3: > - decrement ttl on popping last label when not doing ttl propagation, > as suggested by David Ahern. > - add comment to describe what the somewhat complex conditionals are > doing to work out what ttl to use in mpls_iptunnel.c. > - rearrange fields fields in struct netns_mpls to keep the platform > label fields together, as suggested by David Ahern. > > Changes in v2: > - add references to RFC 3443 as suggested by David Ahern > - fix setting of skb->protocol as noticed by David Ahern > - implement per-route/per-LWT configurability as suggested by Eric > Biederman > - split into two patches for ease of review > > Robert Shearman (2): > mpls: allow TTL propagation to IP packets to be configured > mpls: allow TTL propagation from IP packets to be configured > > Acked-by: Roopa Prabhu