IN SCENARIO BOTH LINKS FROM SAME SERVICE PROVIDER -But how will this avoid drops when PE1and CE1 link goes down as MPBGP bring secondary path as best in BGP table ( MPLS domain )and then to routing table will take atleast 3 min. Till secondry path not in routing table there will be pcket drops.So PE3 will converge so fast.
On 3/26/10, David Prall <d...@dcptech.com> wrote: > > This is where PfR is involved to route around the primary carrier to the > secondary. > > -- > http://dcp.dcptech.com > > > -----Original Message----- > > From: jack daniels [mailto:jckdaniel...@gmail.com] > > Sent: Thursday, March 25, 2010 8:50 PM > > To: David Prall > > Cc: cisco-nsp@puck.nether.net > > Subject: Re: [c-nsp] PFR Question > > > > Hi David, > > > > In a multipath instance PE1 will install the Equal Cost route with rd > > 1:1 > > first, using 1:2 as a secondary path only. Opposite on PE2.??? > > whne both paths have equal cost the why route with rd1:1 will be > > primary always > > and rd 1:2 will be secondary on PE1. > > > > EVEN IF WE advertise X.X.X.X from PE1 and PE2 still PE3 will have two > > routes in BGP table . But one in routing table. > > But how will this avoid drops when PE1and CE1 link goes down as BGP > > bring secondary path to Primary and then to routing table will take > > atleast 3 min. > > > > Regards > > > > > > > > On Fri, Mar 26, 2010 at 12:29 AM, David Prall <d...@dcptech.com> wrote: > > > > > > 1) > > On PE1 > > vrf description customer > > rd 1:1 > > route-target both 1:1 > > route-target import 1:2 > > On PE2 > > vrf description customer > > rd 1:2 > > route-target both 1:2 > > route-target import 1:1 > > > > In a multipath instance PE1 will install the Equal Cost route > > with rd 1:1 > > first, using 1:2 as a secondary path only. Opposite on PE2. > > > > 2) > > Could use different VRF's. Just like dual carriers. A key concern > > is a dual > > failure, site 1 on network 1 and site 2 on network 2. The > > customer will need > > to provide a path between the two networks via one of their > > sites. > > > > > > David > > > > -- > > http://dcp.dcptech.com <http://dcp.dcptech.com/> > > > > > > > -----Original Message----- > > > From: jack daniels [mailto:jckdaniel...@gmail.com] > > > > > Sent: Thursday, March 25, 2010 2:41 PM > > > To: David Prall > > > Cc: cisco-nsp@puck.nether.net > > > Subject: Re: [c-nsp] PFR Question > > > > > > > > Hi David , > > > > > > thanks man I got the basic idea :) > > > > > > 1) but please explain in more detail this > > > > > > Single VRF, 2 distinct RD's. The VRF imports both, exports one. > > The > > > RD's are > > > different so that multipath can be used within the core > > typically. But > > > in > > > this case they wouldn't use multipath and the local RD would be > > used as > > > the > > > determining factor on import of which route is installed > > first.?????? > > > > > > > > > 2) Also if I use diffrent VRF for CE4---CE2 path that will also > > work - > > > ?? > > > > > > > > > On Thu, Mar 25, 2010 at 11:57 PM, David Prall <d...@dcptech.com> > > wrote: > > > > > > > > > If the link goes away, then the update should be pretty > > quick. > > > > > > Single VRF, 2 distinct RD's. The VRF imports both, > > exports one. > > > The RD's are > > > different so that multipath can be used within the core > > > typically. But in > > > this case they wouldn't use multipath and the local RD > > would be > > > used as the > > > determining factor on import of which route is installed > > first. > > > > > > The local CE (CE3) is probing for the subnet at CE1. When > > it is > > > no longer > > > reachable by CE3 it will move the route to CE4. As long > > as CE4 is > > > using CE2 > > > as the path via the cloud then no issue. > > > > > > > > > David > > > > > > -- > > > > > http://dcp.dcptech.com <http://dcp.dcptech.com/> > > <http://dcp.dcptech.com/> > > > > > > > > > > > > -----Original Message----- > > > > From: jack daniels [mailto:jckdaniel...@gmail.com] > > > > > > > Sent: Thursday, March 25, 2010 2:19 PM > > > > To: David Prall > > > > Cc: cisco-nsp@puck.nether.net > > > > Subject: Re: [c-nsp] PFR Question > > > > > > > > > > > If a single carrier, then the CE4/CE2 path needs to be > > via > > > > a second RD so that the paths within the carrier are > > preferred > > > and the > > > > same > > > > will happen.???? > > > > DO YOU mean we need to have diifrent vrf on secondry > > end to end > > > path. > > > > > > > > I didnt get this if single carrier as link PE1 and CE1 > > link > > > fails > > > > ....CE3 send traffic for X.X.X.X to PE3.PE3 still has > > next hop > > > in its > > > > vrf table as PE1.... > > > > > > > > > > > > > > > > > > > > Please help me as still confused if two carriers , how > > will > > > this > > > > hhappen > > > > > > > > > > > > On Thu, Mar 25, 2010 at 11:29 PM, David Prall > > <d...@dcptech.com> > > > wrote: > > > > > > > > > > > > Is MPLS Domain a single carrier, or two carriers. > > If two > > > carriers > > > > then the > > > > CE3/CE4 site will see that they can't reach via > > CE3/CE1 > > > path and > > > > switch over > > > > to CE4/CE2 path. If a single carrier, then the > > CE4/CE2 > > > path needs > > > > to be via > > > > a second RD so that the paths within the carrier > > are > > > preferred > > > > and the same > > > > will happen. PfR is providing end-to-end > > reachability > > > information > > > > in this > > > > case, and based on that changing the local > > routing table. > > > > > > > > David > > > > > > > > > > > > -- > > > > > > > http://dcp.dcptech.com <http://dcp.dcptech.com/> > > <http://dcp.dcptech.com/> > > > <http://dcp.dcptech.com/> > > > > > > > > > > > > > > > > -----Original Message----- > > > > > > > > > From: jack daniels > > [mailto:jckdaniel...@gmail.com] > > > > > Sent: Thursday, March 25, 2010 1:07 PM > > > > > To: David Prall > > > > > Cc: cisco-nsp@puck.nether.net > > > > > Subject: Re: [c-nsp] PFR Question > > > > > > > > > > > > > > But if you have -- > > > > > > > > > > > > > > > |CE1--------PE1 > > > > > PE3--------CE3 > > > > > X.X.X.X---------| ------------ > > -------- > > > MPLS > > > > DOMAIN----- > > > > > -------------- > > > > > | CE2--------PE2 > > > > > PE4--------CE4 > > > > > > > > > > > > > > > Now my primary link is CE1-PE1 and secondary is > > CE2-PE2 > > > > > If my CE1-PE1 goes down i route traffic via > > CE2- > > > PE2<<<<<<I > > > > understand > > > > > this ok... > > > > > > > > > > when traffic from CE3 for X.X.X.X reaches PE3 , > > next > > > hop is > > > > still PE1 ( > > > > > as MPBGP has not converged so fast in MPLS > > domain of > > > SP) ...so > > > > how will > > > > > traffic be forwareded , as PFR claims 3 sec. > > > > > > > > > > > > > > > On Thu, Mar 25, 2010 at 10:16 PM, David Prall > > > <d...@dcptech.com> > > > > wrote: > > > > > > > > > > > > > > > PfR is a unidirectional feature. The > > router on > > > the other > > > > end > > > > > needs to be > > > > > configured with PfR as well in order to > > have > > > > bidirectional > > > > > visibility. > > > > > Typically the master controller will be > > local to > > > the > > > > site. > > > > > > > > > > -- > > > > > > > > > http://dcp.dcptech.com > > <http://dcp.dcptech.com/> <http://dcp.dcptech.com/> > > > <http://dcp.dcptech.com/> > > > > <http://dcp.dcptech.com/> > > > > > > > > > > > > > > > > > > > > > > > > > -----Original Message----- > > > > > > From: cisco-nsp-boun...@puck.nether.net > > > [mailto:cisco- > > > > nsp- > > > > > > boun...@puck.nether.net] On Behalf Of > > jack > > > daniels > > > > > > Sent: Thursday, March 25, 2010 12:35 PM > > > > > > To: cisco-nsp@puck.nether.net > > > > > > Subject: Re: [c-nsp] PFR Question > > > > > > > > > > > > dear guys, > > > > > > > > > > > > is my mail being delivered to group as > > no one > > > replied. > > > > > > > > > > > > On Wed, Mar 24, 2010 at 11:42 PM, jack > > daniels > > > > > > <jckdaniel...@gmail.com>wrote: > > > > > > > > > > > > > Hi Network champs, > > > > > > > > > > > > > > I'm stuck in understanding of PFR . > > Docs say > > > it > > > > converges in > > > > > 3 sec ( > > > > > > for > > > > > > > realtime traffic VOICE )... > > > > > > > > > > > > > > I understand you can send traffic out > > > secondry link > > > > but what > > > > > about > > > > > > traffic > > > > > > > which has to come back from remote > > end ( for > > > which SP > > > > has not > > > > > > converged). > > > > > > > > > > > > > > But if you have -- > > > > > > > > > > > > > > > > > > > > > > > > > > > > |CE1--------PE1 > > > > > > > PE3--------CE3 > > > > > > > X.X.X.X---------| -- > > -------- > > > -------- > > > > --MPLS > > > > > > > DOMAIN------------------- > > > > > > > | CE2-------- > > PE2 > > > > > > > PE4--------CE4 > > > > > > > > > > > > > > > > > > > > > Now my primary link is CE1-PE1 and > > secondary > > > is CE2- > > > > PE2 > > > > > > > If my CE1-PE1 goes down i route > > traffic via > > > CE2- > > > > PE2<<<<<<I > > > > > understand > > > > > > this > > > > > > > ok... > > > > > > > > > > > > > > > > > > > > > BUT MY QUESTION IS - > > > > > > > > > > > > > > PE3 and PE4 ( for this VRF) still has > > NOW > > > converged > > > > the BGP > > > > > and still > > > > > > for > > > > > > > it next hop for X.X.X.X is PE1. So > > how fwd > > > can happen > > > > in 3 > > > > > sec untill > > > > > > > Service providers all routers dont > > converge > > > and > > > > understand > > > > > that CE1- > > > > > > PE1 link > > > > > > > is down. > > > > > > > > > > > > > > > > > > > > > Regards > > > > > > > > > > > > > > > > > > > > > > > > > > > _______________________________________________ > > > > > > cisco-nsp mailing list cisco- > > > n...@puck.nether.net > > > > > > > > https://puck.nether.net/mailman/listinfo/cisco- > > > nsp > > > > > > archive at > > > http://puck.nether.net/pipermail/cisco-nsp/ > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > _______________________________________________ cisco-nsp mailing list cisco-nsp@puck.nether.net https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/