RE: Re[2]: Why we need BGP to establish MPLS? [7:39014]
The question was why was BGP required for MPLS, The explanation provided only stated the functionality that MP-IBGP provides. Not if you should use or not. With the new additions to the IOS, MPLS can now run down on the CE (not full functionality) allowing OSPF to pass VRF information up to the PE. Ken Sexton Data Network Engineering ICG Communications [EMAIL PROTECTED] -Original Message- From: Peter van Oene [mailto:[EMAIL PROTECTED]] Sent: Thursday, March 21, 2002 10:39 AM To: [EMAIL PROTECTED] Subject: RE: Re[2]: Why we need BGP to establish MPLS? [7:39014] I think you really need to mention that you are working on describing RFC2547bis which happens to use MPLS as a forwarding mechanism. The original question asked why BGP was required for MPLS for which the correct answer is that it isn't. At 11:05 AM 3/21/2002 -0500, Sexton, Ken wrote: >MP-iBGP (Multi-Protocol iBGP) is used because it has community extensions >inherent to the routing protocol, to pass VPN related information among the >PE (Provider Edge) routers. Using Extended Communities VPN related >information such as, Route Target (RT), Site of Origin (for dual home CEs) >as well as VPNv4 information can be passed among iBGP peers. Because this is >an iBGP environment, all PEs will receive route updates from everyone else. >(You can use route reflectors to lessen the peer statements). The iBGP >environment requires that all PEs be in sync (global table). The import >statements within the VRF determine which routes to take out of the BGP >global table and install into the VRF routing table. The export statements >indicate which VRF routes will be exported to your iBGP peers. > >You can use an underlying IGP to establish your peers (nothing different >than dealing with normal iBGP). OSPF and IS-IS are the most common IGPs as >they provide addtional hooks within the IOS code to support additional >features such as traffic engineering (examples: support for RSVP, CR-LDP), >etc. > >Ken Sexton >Data Network Engineering >ICG Communications >[EMAIL PROTECTED] > > > > >-Original Message- >From: thinkworker [mailto:[EMAIL PROTECTED]] >Sent: Thursday, March 21, 2002 3:58 AM >To: [EMAIL PROTECTED] >Subject: Re[2]: Why we need BGP to establish MPLS? [7:39014] > > >It seems I had to use IBGP to establish MPLS, so can u explain how can >we setup a MPLS network without BGP? Or maybe U mean using the static >route? > >I should check the book I've got called "MPLS & VPN Architecture & >Implement" of Cisco press (though it is translated very poor) but I had >not the book in my hand:( > > > >By the way, is the book outdated? > >On Thu, 21 Mar 2002 03:19:34 -0500 >"nrf" wrote: > > > You don't need BGP to establish MPLS. > > > > On the other hand, you might need BGP to enable certain 'value-added' MPLS > > applications. > > > > > > ""thinkworker"" wrote in message > > [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... > > > Why we need BGP to establish MPLS? > > > > > > Now we had to use IGP and IBGP to set up MPLS in a AS. It seems quite > > > not necessary. > > > > > > Can anyone help? Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=39059&t=39014 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
RE: Re[2]: Why we need BGP to establish MPLS? [7:39014]
MP-iBGP (Multi-Protocol iBGP) is used because it has community extensions inherent to the routing protocol, to pass VPN related information among the PE (Provider Edge) routers. Using Extended Communities VPN related information such as, Route Target (RT), Site of Origin (for dual home CEs) as well as VPNv4 information can be passed among iBGP peers. Because this is an iBGP environment, all PEs will receive route updates from everyone else. (You can use route reflectors to lessen the peer statements). The iBGP environment requires that all PEs be in sync (global table). The import statements within the VRF determine which routes to take out of the BGP global table and install into the VRF routing table. The export statements indicate which VRF routes will be exported to your iBGP peers. You can use an underlying IGP to establish your peers (nothing different than dealing with normal iBGP). OSPF and IS-IS are the most common IGPs as they provide addtional hooks within the IOS code to support additional features such as traffic engineering (examples: support for RSVP, CR-LDP), etc. Ken Sexton Data Network Engineering ICG Communications [EMAIL PROTECTED] -Original Message- From: thinkworker [mailto:[EMAIL PROTECTED]] Sent: Thursday, March 21, 2002 3:58 AM To: [EMAIL PROTECTED] Subject: Re[2]: Why we need BGP to establish MPLS? [7:39014] It seems I had to use IBGP to establish MPLS, so can u explain how can we setup a MPLS network without BGP? Or maybe U mean using the static route? I should check the book I've got called "MPLS & VPN Architecture & Implement" of Cisco press (though it is translated very poor) but I had not the book in my hand:( By the way, is the book outdated? On Thu, 21 Mar 2002 03:19:34 -0500 "nrf" wrote: > You don't need BGP to establish MPLS. > > On the other hand, you might need BGP to enable certain 'value-added' MPLS > applications. > > > ""thinkworker"" wrote in message > [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... > > Why we need BGP to establish MPLS? > > > > Now we had to use IGP and IBGP to set up MPLS in a AS. It seems quite > > not necessary. > > > > Can anyone help? Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=39037&t=39014 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
RE: certificationZone Bridging White paper ! [7:37393]
Phil, Can I therefore conclude that in a 'Source Route Transparent' Bridge the RIF field will indeed change ? Contrary to the whitepaper. On the above - In SRT mode, you are allowing the router to source route traffic and transparently bridge traffic on the same device (router), but any hosts on either bridging environment can not communicate amongst themselves. (i.e. a host on an SRB network cannot sent traffic destined for a host on the transparent side of the network). The SRT Bridge will never add or remove RIF information from a frame in order for the two technologies to communicate. This is where Source-route Translation bridging (SR/TLB) comes in. Now your above question needs some consideration. The router will now act as a "RIF end station", where a RIF table will be built for end stations on the SRB side, and a forwarding table for the transparent side. By creating a virtual ring within the router, all the token to ethernet frame conversion will take place (i.e MTU, bit ordering, etc) before the frame is sent on its way. It makes no sense to set the RII bit to a "1" when sending the traffic to a transparent end host, as it will not understand what to do with it anyway. Hope this helps Ken Sexton Data Network Engineering ICG Communications [EMAIL PROTECTED] -Original Message- From: Phil Barker [mailto:[EMAIL PROTECTED]] Sent: Wednesday, March 06, 2002 9:02 AM To: [EMAIL PROTECTED] Subject: RE: certificationZone Bridging White paper ! [7:37393] Thanks Ken, >>> SNIP2 The first SRB enabled bridge in the path (from originator to destination) will see that this is an explorer packet and add its route designator (RD) information to the RIF. >>> END SNIP2 Can I therefore conclude that in a 'Source Route Transparent' Bridge the RIF field will indeed change ? Contrary to the whitepaper. Phil. --- "Sexton, Ken" wrote: > Phil, > The first bit within the Source Address Field is > normally the I/G bit, to > define if the source address is individual (unicast) > or group (multicast) > address. In an SRB bridged environment, this one bit > is used to indicate if > any Routing Information Field (RIF) information is > present in the Token > frame following the SA field. > > This bit will be set by hosts with the SRB > environment and used by bridges > to indicate the above. The hosts will keep a > "forwarding table" on how to > reach any required destination host. > > If the host doesn't know how to get to a particular > destination, it will > send out an explorer frame (all routes explorer > -ARE) or a Spanning tree > explorer (SPE) frame to locate the destination. It > will depending on your > bridged environment which explorer frame is used. > > The first SRB enabled bridge in the path (from > originator to destination) > will see that this is an explorer packet and add its > route designator (RD) > information to the RIF. The first bridge will add > the first ring number, > it's bridge number, and the ring number of the > interface it going to send > the explorer packet out of. > > When all said and done - the host will know how to > reach that particular end > host and include RIF information in the token frame. > The RII, will tell the > bridge that a RIF is present and forward the frame > according to the RIF RC > and RD fields. > > Ken Sexton > Data Network Engineering > ICG Communications > [EMAIL PROTECTED] > > > > > -Original Message- > From: Phil Barker > [mailto:[EMAIL PROTECTED]] > Sent: Wednesday, March 06, 2002 6:35 AM > To: [EMAIL PROTECTED] > Subject: certificationZone Bridging White paper ! > [7:37393] > > > Just been re-reading this paper by David Wolfsener. > See SNIP below. > > In the instance where the RII indicator is a 1 the > frame will be 'source routed' if the frame is > 'source > routed' then surely this implies that the RIF must > be > manipulated in order to reflect the true Source > Route > !!! I havn't got my 'Interconnections' with me so I > cannot confirm. > > Any ideas ? > > Phil. > > >>> SNIP > > Source Route Transparent Bridging (SRT) > > SRT works by analyzing the RII bit to determine if a > RIF is present. If the RII bit is 0, then a RIF is > not > present and the frame is transparently bridged. If, > however, the RII bit is 1 and a RIF is present, then > the frame is source routed. Note that SRT bridges do > not add or remove RIFs to frames. By now, you ought > to > wonder how to configure SRT. > > >>> END > > _
RE: certificationZone Bridging White paper ! [7:37393]
In the instance where the RII indicator is a 1 the >frame will be 'source routed' if the frame is 'source >routed' then surely this implies that the RIF must be >manipulated in order to reflect the true Source Route To comment of the above, the RII bit doesn't indicate whether the frame is a specific routed frame or whether it is a explorer frame. It only indicates whether the frame contains RIF information or not. The specifically routed frame indicator is within the RIF (first three bits of the RC field, known as the "type" or "broadcast" bits - 0xx = specifically routed frame, 10x = ARE frame, 11x = SPE frame). Maybe its the way its worded that may be the cause of confusion; I've never read it to verify. Ken Sexton Data Network Engineering ICG Communications [EMAIL PROTECTED] -Original Message- From: Priscilla Oppenheimer [mailto:[EMAIL PROTECTED]] Sent: Wednesday, March 06, 2002 1:04 PM To: [EMAIL PROTECTED] Subject: Re: certificationZone Bridging White paper ! [7:37393] At 08:34 AM 3/6/02, Phil Barker wrote: >Just been re-reading this paper by David Wolfsener. >See SNIP below. > >In the instance where the RII indicator is a 1 the >frame will be 'source routed' if the frame is 'source >routed' then surely this implies that the RIF must be >manipulated in order to reflect the true Source Route The RIF is just referenced (not changed) in frames that are specifically routed. In other words, once the end station has found a route, it just puts it in the frame and the bridges just read it forwards or backwards and route accordingly. Could that be what he's getting at?? On the other hand, I agree with you that on an explorer, an SRT bridge changes the RIF. SRT simply implies a couple things: 1) If the RII is zero, just perform normal Ethernet-style transparent bridging 2) If the RII is one and redundant bridges exits, use the spanning tree to determine which way to forward explorer frames. By the way, SRT is the only form of source route bridging that the IEEE ever standardized. And you can get it for free! ;-) It's in Annex C of IEEE 802.1D, which you can get here: http://standards.ieee.org/getieee802/ Have fun with it! Priscilla >!!! I havn't got my 'Interconnections' with me so I >cannot confirm. > >Any ideas ? > >Phil. > > >>> SNIP > >Source Route Transparent Bridging (SRT) > >SRT works by analyzing the RII bit to determine if a >RIF is present. If the RII bit is 0, then a RIF is not >present and the frame is transparently bridged. If, >however, the RII bit is 1 and a RIF is present, then >the frame is source routed. Note that SRT bridges do >not add or remove RIFs to frames. By now, you ought to >wonder how to configure SRT. > > >>> END > >__ >Do You Yahoo!? >Everything you'll ever need on one web page >from News and Sport to Email and Music Charts >http://uk.my.yahoo.com Priscilla Oppenheimer http://www.priscilla.com Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=37476&t=37393 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
RE: the RD [7:37401]
The RDs in the RIF should always be represented in Hex format. When defining the source-bridge command on the router you define as decimal format. However, with that said, you'll see test questions with the decimal equivalence within the RD fields. In either case, I would know how to convert in both directions, that way you're prepared no matter how it is presented. Ken Sexton Data Network Engineering ICG Communications [EMAIL PROTECTED] -Original Message- From: Mckenzie Bill [mailto:[EMAIL PROTECTED]] Sent: Wednesday, March 06, 2002 9:47 AM To: [EMAIL PROTECTED] Subject: Re: the RD [7:37401] O.k. Let me re phrase my question. How important is it to know how to conevert the RD into hexidecimal? I have the RII and the RIF but then a couple of papers I read stated, and now the easy part...the RD, and then I'm lost. Any help? Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=37432&t=37401 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
RE: certificationZone Bridging White paper ! [7:37393]
Phil, The first bit within the Source Address Field is normally the I/G bit, to define if the source address is individual (unicast) or group (multicast) address. In an SRB bridged environment, this one bit is used to indicate if any Routing Information Field (RIF) information is present in the Token frame following the SA field. This bit will be set by hosts with the SRB environment and used by bridges to indicate the above. The hosts will keep a "forwarding table" on how to reach any required destination host. If the host doesn't know how to get to a particular destination, it will send out an explorer frame (all routes explorer -ARE) or a Spanning tree explorer (SPE) frame to locate the destination. It will depending on your bridged environment which explorer frame is used. The first SRB enabled bridge in the path (from originator to destination) will see that this is an explorer packet and add its route designator (RD) information to the RIF. The first bridge will add the first ring number, it's bridge number, and the ring number of the interface it going to send the explorer packet out of. When all said and done - the host will know how to reach that particular end host and include RIF information in the token frame. The RII, will tell the bridge that a RIF is present and forward the frame according to the RIF RC and RD fields. Ken Sexton Data Network Engineering ICG Communications [EMAIL PROTECTED] -Original Message- From: Phil Barker [mailto:[EMAIL PROTECTED]] Sent: Wednesday, March 06, 2002 6:35 AM To: [EMAIL PROTECTED] Subject: certificationZone Bridging White paper ! [7:37393] Just been re-reading this paper by David Wolfsener. See SNIP below. In the instance where the RII indicator is a 1 the frame will be 'source routed' if the frame is 'source routed' then surely this implies that the RIF must be manipulated in order to reflect the true Source Route !!! I havn't got my 'Interconnections' with me so I cannot confirm. Any ideas ? Phil. >>> SNIP Source Route Transparent Bridging (SRT) SRT works by analyzing the RII bit to determine if a RIF is present. If the RII bit is 0, then a RIF is not present and the frame is transparently bridged. If, however, the RII bit is 1 and a RIF is present, then the frame is source routed. Note that SRT bridges do not add or remove RIFs to frames. By now, you ought to wonder how to configure SRT. >>> END __ Do You Yahoo!? Everything you'll ever need on one web page from News and Sport to Email and Music Charts http://uk.my.yahoo.com Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=37398&t=37393 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
