Check the OSPF RFC as well for conditions when an LSA type 3 is generated. If the
Reference: http://www.ietf.org/rfc/rfc2328.txt 12.4.3. Summary-LSAs o Else, if the next hops associated with this set of paths belong to Area A itself, do not generate a summary-LSA for the route.[18] This is the logical equivalent of a Distance Vector protocol's split horizon logic. /Jeff On Mon, Nov 19, 2012 at 4:21 PM, <[email protected]> wrote: > Thanks Jeff, that makes sense... Without the sham link, the customer routers > never even sees the routes coming in from the PE. With the sham link, they > are advertised from the PE to CE as type 1 or type 2 LSA's, so we can adjust > the cost of the backdoor path and/or MPLS path to control how traffic is > routed. > > Doug > > -------- Original Message -------- > Subject: Re: [OSL | CCIE_RS] OSPF behavior with MPLS VPN, backdoor > link, no sham link > From: Jeff Andiorio <[email protected]> > Date: Mon, November 19, 2012 10:42 am > To: Michael Davis - Webquor <[email protected]> > Cc: "[email protected]" <[email protected]>, > "[email protected]" <[email protected]> > > This link does call out the PE will not create a Type3 LSA if Type 1 > is received from the site. > > http://www.cisco.com/en/US/docs/solutions/Enterprise/WAN_and_MAN/L3VPNCon.html > > Jeff > > On Thu, Nov 15, 2012 at 4:40 PM, Michael Davis - Webquor > <[email protected]> wrote: >> Thanks Doug that seems to make sense. I will give your gns3 topology a go >> >> Sent from my iPhone >> >> On 15/11/2012, at 11:36 PM, "[email protected]" <[email protected]> wrote: >> >>> Actually, I mean the OSPF routes (originating from the remote customer >>> site, advertised across the back-door link to the local CE, and then >>> advertised to the local PE) have an AD of 110, while the BGP routes >>> (advertised via OSPF from the remote site CE to the the remote PE, then >>> redistributed into BGP and advertised to the local PE) have an AD of >>> 200. So the PE selects the OSPF routes to insert into the VRF routing >>> table, and the BGP routes never get re-distributed. >>> >>> Here's a link to the GNS3 topology I'm using for this. Have a quick >>> look, it will make much more sense than my rambling on... >>> http://gns3vault.com/MPLS/advanced-mpls-vpn.html >>> >>> Thanks, >>> >>> Doug >>> >>> >>> >>> >>> -------- Original Message -------- >>> Subject: Re: [OSL | CCIE_RS] OSPF behavior with MPLS VPN, backdoor >>> link, no sham link >>> From: Steve Storniak <[email protected]> >>> Date: Thu, November 15, 2012 7:23 am >>> To: "[email protected]" <[email protected]>, >>> "[email protected]" <[email protected]> >>> >>> Did you mean local CE routes (internal) have high priority over BGP >>> routes(external) per ospf route selection process? >>> >>> >>> >>> Steve >>> >>> >>> From: [email protected] <[email protected]>; >>> To: <[email protected]>; >>> Subject: Re: [OSL | CCIE_RS] OSPF behavior with MPLS VPN, backdoor >>> link, no sham link >>> Sent: Thu, Nov 15, 2012 11:05:13 AM >>> >>> Specifying the both external and internal types when re-distributing >>> into MP-BGP doesn't seem to make a difference. Since they are all >>> internal routes, the distribution works without specifying the route >>> types, as evidenced by the Type 3 LSA's and O IA routes showing up when >>> I shut down the back-door link. >>> >>> But I think I have the answer... Here's an excerpt from "sh ip bgp vpnv4 >>> vrf MELON" from the PE router that connects to one customer site, let's >>> call it "Customer Site A". This was taken while the back-door link was >>> up: >>> >>> *> 12.12.12.12/32 192.168.23.2 111 32768 ? >>> * i 5.5.5.5 11 100 0 ? >>> >>> And here an excerpt from "show ip route vrf MELON" for the same route: >>> >>> O 12.12.12.12 [110/111] via 192.168.23.2, 00:00:04, Ethernet0/3 >>> 13.0.0.0/32 is subnetted, 1 subnets >>> >>> 192.168.23.2 is the CE router at "Customer Site A", while 5.5.5.5 is the >>> PE router loopback that connects to "Customer Site B" and 12.12.12.12 is >>> the loopback of the CE router at "Customer Site B". >>> >>> Only active routes, present in the VRF's routing table, are >>> re-distributed. Since the OSPF routes from the local CE have a lower AD >>> than the BGP routes from the other site, the OSPF routes are active in >>> the VRF's routing table, not the BGP routes. So the BGP routes from the >>> other site coming across the MPLS VPN never get redistributed into OSPF, >>> so the LSA's don't get created. >>> >>> Does this sound correct? >>> >>> Doug >>> >>> >>> >>> >>> -------- Original Message -------- >>> Subject: Re: [OSL | CCIE_RS] OSPF behavior with MPLS VPN, backdoor >>> link, no sham link >>> From: Greg Chisholm <[email protected]> >>> Date: Wed, November 14, 2012 8:21 pm >>> To: [email protected] >>> >>> On 11/14/2012 05:12 PM, [email protected] wrote: >>>> I'm working on a sham link lab, and came across some behavior I don't >>>> understand. I've got the MPLS L3VPN built, and routes are being learned >>>> across it properly. Everything is in area 0, and I've used the same >>>> process ID for the vrf on both PE's. I do not have the sham link >>>> configured yet, so all traffic is going over the back-door link. >>>> >>>> The thing I don't understand is that there are no Type3 LSA's anywhere, >>>> not on the CE routers, nor on the PE vrf's. I only see type 1 and Type 2 >>>> LSA's. If I shut down the back-door link, the Type 3's show up, along >>>> with the O IA routes as expected. >>>> >>>> I would think that while the back-door is up, we would see the Type 2 >>>> LSA's coming across the back-door link, as well as the Type 3 LSA's >>>> being redistributed from MP-BGP. >>>> >>>> What am I missing? >>>> >>>> Thanks, >>>> >>>> Doug >>>> _______________________________________________ >>>> For more information regarding industry leading CCIE Lab training, >>>> please visit www.ipexpert.com >>>> >>>> Are you a CCNP or CCIE and looking for a job? Check out >>>> www.PlatinumPlacement.com >>>> >>>> http://onlinestudylist.com/mailman/listinfo/ccie_rs >>> >>> Look at your redistribution in BGP, you need to specify the types of >>> OSPF routes with redistribute ospf >>> _______________________________________________ >>> For more information regarding industry leading CCIE Lab training, >>> please visit www.ipexpert.com >>> >>> Are you a CCNP or CCIE and looking for a job? Check out >>> www.PlatinumPlacement.com >>> >>> http://onlinestudylist.com/mailman/listinfo/ccie_rs >>> _______________________________________________ >>> For more information regarding industry leading CCIE Lab training, >>> please visit www.ipexpert.com >>> >>> Are you a CCNP or CCIE and looking for a job? Check out >>> www.PlatinumPlacement.com >>> >>> http://onlinestudylist.com/mailman/listinfo/ccie_rs >>> _______________________________________________ >>> For more information regarding industry leading CCIE Lab training, please >>> visit www.ipexpert.com >>> >>> Are you a CCNP or CCIE and looking for a job? Check out >>> www.PlatinumPlacement.com >>> >>> http://onlinestudylist.com/mailman/listinfo/ccie_rs >> _______________________________________________ >> For more information regarding industry leading CCIE Lab training, please >> visit www.ipexpert.com >> >> Are you a CCNP or CCIE and looking for a job? Check out >> www.PlatinumPlacement.com >> >> http://onlinestudylist.com/mailman/listinfo/ccie_rs _______________________________________________ For more information regarding industry leading CCIE Lab training, please visit www.ipexpert.com Are you a CCNP or CCIE and looking for a job? Check out www.PlatinumPlacement.com http://onlinestudylist.com/mailman/listinfo/ccie_rs
