I have never done it without loopbacks, but you can try with explicit-null.
The command is

mpls ldp explicit-null

Run that on all core routers. Not 100% positive but may be worth a shot...

On Sat, Nov 21, 2009 at 10:53 AM, Brad Edgeworth
<[email protected]>wrote:

>  Got it working.
>
>
>
> I tried it with the Core & Without the core running as part of the BGP
> process not using loopback addresses and was not successful (routes would
> still pass to the CE devices).   If I used loopbacks on the bgp peering
> either scenario would work (with & without the core BGP peering).  The main
> thing I can tell is that the mpls forwarding table has changed a tag for the
> core loopback one of the loopbacks from Untagged to a Pop.
>
>
>
> So is there anyway you can add an entry into the LDP table manually, or do
> a basic MPLS setup w/o peering with loopbacks?
>
>
>
> -brad
>
>
>
> *From:* [email protected] [mailto:
> [email protected]] *On Behalf Of *Brad Edgeworth
> *Sent:* Saturday, November 21, 2009 10:31 AM
> *To:* Joe Astorino; Solomon Ayele
>
> *Cc:* [email protected]
> *Subject:* Re: [OSL | CCIE_RS] Need help with L3 MPLS
>
>
>
> I thought the iBGP route-reflector-client would allow the routes learned
> from R1Core to R2Core.  It appears as if that is working?  Can you explain
> the flaw in my logic?     Curious as to why the subnet id’s need to match
> for the loopbacks?   I noticed that some of the VRF routes are not in the
> mpls forwarding table.  Is that normal?
>
>
>
> My regular R1 & R2 routers (Naming convention wasn’t the greatest) aren’t
> running BGP and do not have VRF apply.   VRF is defined only on R1Core &
> R2Core.
>
>
>
>
>
> More Info from the original configs:
>
>
>
> R1:
>
> Show ip route
>
>      10.0.0.0/24 is subnetted, 2 subnets
>
> C       10.32.1.0 is directly connected, FastEthernet0/0
>
> O E2    10.64.1.0 [110/1] via 10.32.1.254, 11:03:48, FastEthernet0/0
>
> C    192.168.1.0/24 is directly connected, Loopback0
>
>      192.168.2.0/32 is subnetted, 1 subnets
>
> O E2    192.168.2.2 [110/2] via 10.32.1.254, 11:03:50, FastEthernet0/0
>
>
>
> R1Core:
>
> Sho ip route
>
>     172.32.0.0/24 is subnetted, 2 subnets
>
> C       172.32.32.0 is directly connected, FastEthernet0/1
>
> O IA    172.32.64.0 [110/129] via 192.168.1.254, 10:57:30, Serial0/0
>
> C    192.168.1.0/24 is directly connected, Serial0/0
>
> O    192.168.2.0/24 [110/128] via 192.168.1.254, 10:57:32, Serial0/0
>
>    92.168.100.0/24 is variably subnetted, 3 subnets, 2 masks
>
> C       192.168.100.0/24 is directly connected, Loopback0
>
> O       192.168.100.2/32 [110/129] via 192.168.1.254, 10:57:32, Serial0/0
>
> O       192.168.100.254/32 [110/65 <http://192.168.100.254/32%5B110/65>]
> via 192.168.1.254, 10:57:32, Serial0/0
>
>
>
> Sho ip route vrf BRAD
>
>      10.0.0.0/24 is subnetted, 2 subnets
>
> C       10.32.1.0 is directly connected, FastEthernet0/0
>
> B       10.64.1.0 [200/0] via 192.168.2.1, 10:58:40
>
>     192.168.1.0/32 is subnetted, 1 subnets
>
> O       192.168.1.1 [110/2] via 10.32.1.1, 10:59:25, FastEthernet0/0
>
>      192.168.2.0/32 is subnetted, 1 subnets
>
> B       192.168.2.2 [200/2] via 192.168.2.1, 10:58:40
>
>
>
> R1Core#show mpls forwarding-table
>
> Local  Outgoing    Prefix            Bytes tag  Outgoing   Next Hop
>
> tag    tag or VC   or Tunnel Id      switched   interface
>
> 16     Untagged    192.168.100.254/32   \
>
>                                      0          Se0/0      point2point
>
> 17     16          192.168.100.2/32  0          Se0/0      point2point
>
> 18     Pop tag     192.168.2.0/24    0          Se0/0      point2point
>
> 19     18          172.32.64.0/24    0          Se0/0      point2point
>
> 20     Aggregate   10.32.1.0/24[V] <http://10.32.1.0/24%5BV%5D>   0
>
> 21     Untagged    192.168.1.1/32[V] <http://192.168.1.1/32%5BV%5D>0          
> Fa0/0      10.32.1.1
>
>
>
> R2Core:
>
> Sho IP Route
>
>      172.32.0.0/24 is subnetted, 2 subnets
>
> O IA    172.32.32.0 [110/129] via 192.168.2.254, 11:02:18, Serial0/0
>
> C       172.32.64.0 is directly connected, FastEthernet0/1
>
> O    192.168.1.0/24 [110/128] via 192.168.2.254, 11:02:28, Serial0/0
>
> C    192.168.2.0/24 is directly connected, Serial0/0
>
>      192.168.100.0/24 is variably subnetted, 3 subnets, 2 masks
>
> C       192.168.100.0/24 is directly connected, Loopback0
>
> O       192.168.100.1/32 [110/129] via 192.168.2.254, 11:02:19, Serial0/0
>
> O       192.168.100.254/32 [110/65 <http://192.168.100.254/32%5B110/65>]
> via 192.168.2.254, 11:02:29, Serial0/0
>
>
>
> Sho ip route vrf BRAD
>
>      10.0.0.0/24 is subnetted, 2 subnets
>
> B       10.32.1.0 [200/0] via 192.168.1.1, 11:02:24
>
> C       10.64.1.0 is directly connected, FastEthernet0/0
>
>      192.168.1.0/32 is subnetted, 1 subnets
>
> B       192.168.1.1 [200/2] via 192.168.1.1, 11:02:25
>
>      192.168.2.0/32 is subnetted, 1 subnets
>
> O       192.168.2.2 [110/2] via 10.64.1.1, 11:03:41, FastEthernet0/0
>
>
>
> R2Core#sho mpls forwarding-table
>
> Local  Outgoing    Prefix            Bytes tag  Outgoing   Next Hop
>
> tag    tag or VC   or Tunnel Id      switched   interface
>
> 16     Untagged    192.168.100.254/32   \
>
>                                      0          Se0/0      point2point
>
> 18     Pop tag     192.168.1.0/24    0          Se0/0      point2point
>
> 19     17          192.168.100.1/32  0          Se0/0      point2point
>
> 20     19          172.32.32.0/24    0          Se0/0      point2point
>
> 21     Aggregate   10.64.1.0/24[V] <http://10.64.1.0/24%5BV%5D>   0
>
> 22     Untagged    192.168.2.2/32[V] <http://192.168.2.2/32%5BV%5D>0          
> Fa0/0      10.64.1.1
>
>
>
> R2
>
> Sho ip route
>
>      10.0.0.0/24 is subnetted, 2 subnets
>
> O E2    10.32.1.0 [110/1] via 10.64.1.254, 11:04:20, FastEthernet0/0
>
> C       10.64.1.0 is directly connected, FastEthernet0/0
>
>      192.168.1.0/32 is subnetted, 1 subnets
>
> O E2    192.168.1.1 [110/2] via 10.64.1.254, 11:04:20, FastEthernet0/0
>
> C    192.168.2.0/24 is directly connected, Loopback0
>
>
>
> *From:* Joe Astorino [mailto:[email protected]]
> *Sent:* Saturday, November 21, 2009 6:08 AM
> *To:* Solomon Ayele
> *Cc:* [email protected]; Brad Edgeworth
> *Subject:* Re: [OSL | CCIE_RS] Need help with L3 MPLS
>
>
>
> Bryan is right...peer with your loopbacks or the PHP process will happen
> too soon and you will run into issues.  If you are doing this over
> frame-relay make sure your frame-relay is running point-to-multipoint as
> well.  Also make sure your OSPF is advertising in the actual mask of your
> loopback interfaces (may require ip ospf network point-to-point if you have
> anything other than /32).
>
> Also like Bryan said, the P router need not run BGP ...that is part of the
> glory of this technology.  It just needs to have labels to the BGP exit
> points (needs labels for the PE routers loopbacks) and can simply do tag
> switching.
>
> On Sat, Nov 21, 2009 at 3:15 AM, Solomon Ayele <[email protected]> wrote:
>
>
>
>
>
> Hi Brad,
>
> As it can be seen your VPNV4 peering is like this R1Core (PE) <–
> >CoreCentral <– >R2Core (PE).
>
> Therefore R1 has a peering to Core with iBGP and VPNV4 is activated. Good
> R1 has a knowledge of VRF and it can import and export the respective VPNV4
> addresses to vrf but that is not true for Rcore.
>
>
>
> The other thing is the core has a iBGP peerings with both routers so it
> will not pass the route that it got from one to another. Even if you can
> solve this issue with route reflector or confederation, you have to work
> around to get the VPNV4 traffic around. May be you have to configure the
> Core with vrf ....
>
>
>
> The best way is to peer the two PE routers directly.
>
> The other thing is it is not a must to peer with loopbacks
>
>
>
> Best Regards,
>
>
>
> Solomon
>
>
>
>
>  ------------------------------
>
> *From:* Brad Edgeworth <[email protected]>
> *To:* "[email protected]" <[email protected]>
> *Sent:* Sat, November 21, 2009 8:48:52 AM
> *Subject:* [OSL | CCIE_RS] Need help with L3 MPLS
>
>
>
> So I’m trying to practice MPLS L3 VPN with routing OSPF across it.   I’m
> having difficulties with my connectivity from one CE device to the other CE
> device.   Before I started I had plain MPLS working on a flat network end to
> end.   I’m successful with getting my OSPF routes across the cloud but need
> help figuring out why packets won’t travel.   Can someone find what I’m
> missing?
>
>
>
> -brad
>
>
>
>
>
>
>
> Setup is straightforward:    R1 (CE) – R1Core (PE) – CoreCentral – R2Core
> (PE) – R2 (CE)
>                                                                 10.x.x.x
> subnets are data networks for the CE
>
>                                                                 192.168.x.x
> subnets are the provider network
>
>
>
> Routing portion of the configs listed below:
>
>
>
> **R1Core
>
> router ospf 100 vrf BRAD
>
>  domain-id 0.0.0.1
>
>  log-adjacency-changes
>
>  redistribute bgp 100 subnets
>
>  network 10.32.0.0 0.0.255.255 area 1
>
> router ospf 1
>
>  log-adjacency-changes
>
>  network 172.0.0.0 0.255.255.255 area 1
>
>  network 192.168.0.0 0.0.255.255 area 0
>
> router bgp 100
>
>  no bgp default ipv4-unicast
>
>  bgp log-neighbor-changes
>
>  neighbor 192.168.1.254 remote-as 100
>
>  !
>
>  address-family vpnv4
>
>   neighbor 192.168.1.254 activate
>
>   neighbor 192.168.1.254 send-community both
>
>  exit-address-family
>
>  !
>
>  address-family ipv4 vrf BRAD
>
>   redistribute connected
>
>   redistribute ospf 100 vrf BRAD
>
>   no synchronization
>
>  exit-address-family
>
>
>
>
>
> **** CoreCentral
>
> router ospf 1
>
>  mpls ldp autoconfig
>
>  log-adjacency-changes
>
>  network 0.0.0.0 255.255.255.255 area 0
>
> router bgp 100
>
>  no bgp default ipv4-unicast
>
>  bgp log-neighbor-changes
>
>  neighbor 192.168.1.1 remote-as 100
>
>  neighbor 192.168.2.1 remote-as 100
>
> !
>
>  address-family vpnv4
>
>   neighbor 192.168.1.1 activate
>
>   neighbor 192.168.1.1 send-community extended
>
>   neighbor 192.168.1.1 route-reflector-client
>
>   neighbor 192.168.2.1 activate
>
>   neighbor 192.168.2.1 send-community extended
>
>   neighbor 192.168.2.1 route-reflector-client
>
> exit-address-family
>
>
>
>
>
> **R2Core
>
> router ospf 100 vrf BRAD
>
>  domain-id 0.0.0.2
>
>  log-adjacency-changes
>
>  redistribute bgp 100 subnets
>
>  network 10.64.0.0 0.0.255.255 area 2
>
> router ospf 1
>
>  log-adjacency-changes
>
>  network 172.0.0.0 0.255.255.255 area 2
>
>  network 192.168.0.0 0.0.255.255 area 0
>
> router bgp 100
>
>  no bgp default ipv4-unicast
>
>  bgp log-neighbor-changes
>
>  neighbor 192.168.2.254 remote-as 100
>
>  !
>
>  address-family vpnv4
>
>   neighbor 192.168.2.254 activate
>
>   neighbor 192.168.2.254 send-community both
>
>  exit-address-family
>
>  !
>
>  address-family ipv4 vrf BRAD
>
>   redistribute connected
>
>   redistribute ospf 100 vrf BRAD
>
>   no synchronization
>
>  exit-address-family
>
>
>
>
>
>
> _______________________________________________
> For more information regarding industry leading CCIE Lab training, please
> visit www.ipexpert.com
>
>
>
>
> --
> Regards,
>
> Joe Astorino CCIE #24347 (R&S)
> Sr. Technical Instructor - IPexpert
> Mailto: [email protected]
> Telephone: +1.810.326.1444
> Live Assistance, Please visit: www.ipexpert.com/chat
> eFax: +1.810.454.0130
>
> IPexpert is a premier provider of Classroom and Self-Study Cisco CCNA (R&S,
> Voice & Security), CCNP, CCVP, CCSP and CCIE (R&S, Voice, Security & Service
> Provider) Certification Training with locations throughout the United
> States, Europe and Australia. Be sure to check out our online communities at
> www.ipexpert.com/communities and our public website at www.ipexpert.com
>
> _______________________________________________
> For more information regarding industry leading CCIE Lab training, please
> visit www.ipexpert.com
>
>


-- 
Bryan Bartik
CCIE #23707 (R&S, SP), CCNP
Sr. Support Engineer - IPexpert, Inc.
URL: http://www.IPexpert.com
_______________________________________________
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