Hi Satya, Please see inline..
On Wed, Feb 10, 2021 at 8:37 AM Satya Mohanty (satyamoh) <satya...@cisco.com> wrote: > Hi Tulasi and Muthu, > > > > Yes, the numeric value here refers to the 4byte or 16byte unsigned value > representation of the IP address field. > > Maybe in the 7432-bis this can be stated explicitly. > Agree, this is important to clarify in 7432-bis and simple to fix in implementations that don't compare IPv4 and IPv6 addresses this way for default DF election algo.. > > > We did envision this possibility in RFC 8584 (the HRW hash already takes > care of the fact that the IP address could be either IPV4 or IPV6). > > > > However, with respect to deployment do you have a case in mind of this > “mixed v4/v6” that will necessitate such a tie-break? > > I mean one of the MH PEs has an ipv4 originator address and the other a v6 > originator address. > Yes, in a dual-stack environment, there could be multihomed PEs running (1) BGP over IP4 w/ IPv4 NH, (2) BGP over IPv6 w/ IPv4 NH, (3) BGP over IPv6 w/ IPv6 NH, say connected thru' an RR in control plane, and all part of the same ES group. In this case, the Originating Router's IP address in the ES route could be an IPv4 or IPv6 address (implementation specific).. Regards, Muthu > > > Thanks, > > --Satya > > > > > > *From: *BESS <bess-boun...@ietf.org> on behalf of TULASI RAM REDDY < > tulasiramire...@gmail.com> > *Date: *Friday, February 5, 2021 at 5:17 AM > *To: *Muthu Arul Mozhi Perumal <muthu.a...@gmail.com> > *Cc: *"bess@ietf.org" <bess@ietf.org> > *Subject: *Re: [bess] RFC 8584: EVPN DF Election - Originating Router's > IP Address of different address family > > > > Thanks Muthu. > > Shouldn't numeric value here mean simply the 4byte or 16 byte unsigned > value representation of the IP address field? > > Thinking loudly on how to interpret numeric value and the limitations > here. Any comments? > > > > each PE builds an ordered list of the IP > > addresses of all the PE nodes connected to the Ethernet segment > > (including itself), in *increasing numeric value* > > > > Thanks, > > Tulasi. > > On Fri, Feb 5, 2021 at 3:15 PM Muthu Arul Mozhi Perumal < > muthu.a...@gmail.com> wrote: > > Hi Tulasi, > > > > I think the problem is, there is no standard way to numerically compare > IPv4 with IPv6 addresses to form an ordered list. So, all the PEs > multihomed to an ES may not always arrive at the same DF (or BFD in the > case of single-active L-LINE service) with the default DF election algo. > This is problematic (and may cause traffic loops). Hence, the default DF > election algo works only when all PEs multihomed to an ES have Originating > Router's IP Address of the same AF.. > > > > Regards, > > Muthu > > > > On Thu, Feb 4, 2021 at 7:58 PM TULASI RAM REDDY <tulasiramire...@gmail.com> > wrote: > > Hi All, > > > > As mentioned in the Problem Statement of RFC8584 Sec 1.3, Default DF > algorithm is expected to have > > all multihomed PEs to have Originating IP of the same address family. > > Do we see any interop issue if the different address families are > considered, i.e. ordering in > > ascending order based on numerical value in Originating IP here? For IPv4 > read 4 octets as unsigned integer > > and IPv6 is considered as 16 octet unsigned integer. > > > 1.3 <https://tools.ietf.org/html/rfc8584#section-1.3>. Problem Statement > > Default DF election algorithm assumes > > that all the PEs who are multihomed to the same ES (and interested in > > the DF election by exchanging EVPN routes) use an Originating > > Router's IP address [RFC7432 <https://tools.ietf.org/html/rfc7432>] of the > same family. > > > > Thanks, > > TULASI RAMI REDDY N > > _______________________________________________ > BESS mailing list > BESS@ietf.org > https://www.ietf.org/mailman/listinfo/bess > > > > -- > > TULASI RAMI REDDY N >
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