Re: Inter AS MPLS L3VPN Option C - ASBRs Peering BGP+Label

Hello

Although I dont have topo diagram to refer to your case ; I can just
summarize few points in option C :

1) next-hop-unchanged is required on RR in case they are falling in
forwarding paths
2) LSP will be end to end .(across both AS , there is no change in next-hop
anywhere and hence single LSP)
3) In case you have IOS<-> XR as your ASBRs then

on ios side : send-label ( i belive mpls bgp fwd command will come
automatic)
on xr side : address-family labeled unicast AND a /32 static route

If you can share topo and running configs ; I can have a look

Regards
Gaurav Madan

On 5 June 2014 12:38, Maarten Vervoorn <mr.vervoorn_at_gmail.com> wrote:

> Hi Brian,
>
> Thanks for helping me.
>
> The link for EBGP+Labels is between R1 and XR1 just like your example
> video. This is the link is 10.10.101.0/24 (R1 .1 and XR1 .19). The host
> route should then be present on XR1 right? R1 is IOS so it will
> automatically do that for you. XR2 is the route reflector which has a EBGP
> VPNV4 connection to R2. I have not created an host route on XR2 Anywhay
> Below are the routing tabels of R1, XR1 and R6 and XR2.
>
> R1:
> R1#sh ip route | b Gateway
> Gateway of last resort is not set
> 1.0.0.0/32 is subnetted, 1 subnets
> C 1.1.1.1 is directly connected, Loopback1
> 2.0.0.0/32 is subnetted, 1 subnets
> i L2 2.2.2.2 [115/30] via 10.10.13.3, 00:10:36, Ethernet0/0
> 3.0.0.0/32 is subnetted, 1 subnets
> i L2 3.3.3.3 [115/20] via 10.10.13.3, 00:10:36, Ethernet0/0
> 4.0.0.0/32 is subnetted, 1 subnets
> i L2 4.4.4.4 [115/30] via 10.10.13.3, 00:10:36, Ethernet0/0
> 5.0.0.0/32 is subnetted, 1 subnets
> B 5.5.5.5 [20/12] via 10.10.101.19, 00:07:36
> 10.0.0.0/8 is variably subnetted, 7 subnets, 2 masks
> C 10.10.13.0/24 is directly connected, Ethernet0/0
> L 10.10.13.1/32 is directly connected, Ethernet0/0
> i L2 10.10.23.0/24 [115/20] via 10.10.13.3, 00:10:36, Ethernet0/0
> i L2 10.10.34.0/24 [115/20] via 10.10.13.3, 00:10:36, Ethernet0/0
> C 10.10.101.0/24 is directly connected, Ethernet0/1.101
> L 10.10.101.1/32 is directly connected, Ethernet0/1.101
> C 10.10.101.19/32 is directly connected, Ethernet0/1.101
> 20.0.0.0/32 is subnetted, 1 subnets
> B 20.20.20.20 [20/12] via 10.10.101.19, 00:07:36
>
> XR1:
> RP/0/0/CPU0:XR1#sh route | b Gateway
> Sat May 17 05:12:05.060 UTC
> Gateway of last resort is not set
> B 2.2.2.2/32 [20/30] via 10.10.101.1, 00:08:18
> B 4.4.4.4/32 [20/30] via 10.10.101.1, 00:08:18
> O 5.5.5.5/32 [110/12] via 10.10.196.6, 00:09:19,
> GigabitEthernet0/0/0/0.196
> O 6.6.6.6/32 [110/2] via 10.10.196.6, 00:09:19,
> GigabitEthernet0/0/0/0.196
> O 10.10.56.0/24 [110/11] via 10.10.196.6, 00:09:19,
> GigabitEthernet0/0/0/0.196
> C 10.10.101.0/24 is directly connected, 00:09:20,
> GigabitEthernet0/0/0/0.101
> S 10.10.101.1/32 is directly connected, 00:09:20,
> GigabitEthernet0/0/0/0.101
> L 10.10.101.19/32 is directly connected, 00:09:20,
> GigabitEthernet0/0/0/0.101
> C 10.10.196.0/24 is directly connected, 00:09:20,
> GigabitEthernet0/0/0/0.196
> L 10.10.196.19/32 is directly connected, 00:09:20,
> GigabitEthernet0/0/0/0.196
> O 10.10.206.0/24 [110/11] via 10.10.196.6, 00:09:19,
> GigabitEthernet0/0/0/0.196
> L 19.19.19.19/32 is directly connected, 00:09:20, Loopback1
> O 20.20.20.20/32 [110/12] via 10.10.196.6, 00:08:59,
> GigabitEthernet0/0/0/0.196
>
> R6:
> R6#sh ip route | b Gateway
> Gateway of last resort is not set
> 2.0.0.0/32 is subnetted, 1 subnets
> O E2 2.2.2.2 [110/1] via 10.10.196.19, 00:08:57, Ethernet0/0.196
> 4.0.0.0/32 is subnetted, 1 subnets
> O E2 4.4.4.4 [110/1] via 10.10.196.19, 00:08:57, Ethernet0/0.196
> 5.0.0.0/32 is subnetted, 1 subnets
> O 5.5.5.5 [110/11] via 10.10.56.5, 00:11:32, Ethernet0/0.56
> 6.0.0.0/32 is subnetted, 1 subnets
> C 6.6.6.6 is directly connected, Loopback1
> 10.0.0.0/8 is variably subnetted, 6 subnets, 2 masks
> C 10.10.56.0/24 is directly connected, Ethernet0/0.56
> L 10.10.56.6/32 is directly connected, Ethernet0/0.56
> C 10.10.196.0/24 is directly connected, Ethernet0/0.196
> L 10.10.196.6/32 is directly connected, Ethernet0/0.196
> C 10.10.206.0/24 is directly connected, Ethernet0/0.206
> L 10.10.206.6/32 is directly connected, Ethernet0/0.206
> 19.0.0.0/32 is subnetted, 1 subnets
> O 19.19.19.19 [110/11] via 10.10.196.19, 00:09:53, Ethernet0/0.196
> 20.0.0.0/32 is subnetted, 1 subnets
> O 20.20.20.20 [110/11] via 10.10.206.20, 00:09:33, Ethernet0/0.206
>
> XR2:
> RP/0/0/CPU0:XR2#sh ip route | b Gateway
> Wed Jun 4 23:13:52.736 UTC
> Gateway of last resort is not set
> O E2 2.2.2.2/32 [110/1] via 10.10.206.6, 00:10:56,
> GigabitEthernet0/0/0/0.206
> O E2 4.4.4.4/32 [110/1] via 10.10.206.6, 00:10:56,
> GigabitEthernet0/0/0/0.206
> O 5.5.5.5/32 [110/12] via 10.10.206.6, 00:11:38,
> GigabitEthernet0/0/0/0.206
> O 6.6.6.6/32 [110/2] via 10.10.206.6, 00:11:38,
> GigabitEthernet0/0/0/0.206
> O 10.10.56.0/24 [110/11] via 10.10.206.6, 00:11:38,
> GigabitEthernet0/0/0/0.206
> O 10.10.196.0/24 [110/11] via 10.10.206.6, 00:11:38,
> GigabitEthernet0/0/0/0.206
> C 10.10.206.0/24 is directly connected, 00:11:46,
> GigabitEthernet0/0/0/0.206
> L 10.10.206.20/32 is directly connected, 00:11:46,
> GigabitEthernet0/0/0/0.206
> O 19.19.19.19/32 [110/12] via 10.10.206.6, 00:11:38,
> GigabitEthernet0/0/0/0.206
> L 20.20.20.20/32 is directly connected, 00:11:46, Loopback1
>
> Kind regards,
>
> Maarten Vervoorn
>
>
> 2014-06-05 1:05 GMT+02:00 Brian McGahan <bmcgahan_at_ine.com>:
>
> > Is 10.10.206.0 the link that the EBGP + Label peering is established on?
> > If so, what is XR2's route to 10.10.206.6? It needs to be a host route
> in
> > order to perform the MPLS encapsulation. Post the "show ip route" from
> R6
> > and XR2.
> >
> > Brian McGahan, 4 x CCIE #8593 (R&S/SP/SC/DC), CCDE #2013::13
> > bmcgahan_at_INE.com
> >
> > Internetwork Expert, Inc.
> > http://www.INE.com
> >
> > -----Original Message-----
> > From: nobody_at_groupstudy.com [mailto:nobody_at_groupstudy.com] On Behalf Of
> > Maarten Vervoorn
> > Sent: Wednesday, June 04, 2014 2:53 PM
> > To: Cisco certification
> > Subject: Inter AS MPLS L3VPN Option C - ASBRs Peering BGP+Label
> >
> > Hi all,
> >
> > I'm studying for CCIE service provider with the INE all access pass.
> After
> > watching the video about:"Inter AS MPLS L3VPN Option C - ASBRs Peering
> > BGP+Label " I build the lab my self-according to the same diagram used
> > BGP+in
> > the video with the exact same setup. I tried to follow the movie as much
> > as possible to learn the technology. I started with the configuration
> where
> > the traffic still flows over the route reflector so the ebgp peers still
> > are changing the next-hop vaue. That is where my issueis. The control
> plane
> > is correct I received all routes in all VRFb s The dataplane for VRF B
> and
> > C is also correct because I can reach the loopback addresses within the
> VRF.
> > However the dataplane of VRF A is not working. I cannot reach the
> loopback
> > address. I have researched the issue and found out where the problem is
> and
> > how I can resolve it. However I failed to figure out exactly why this
> > behavior is like this so maybe you can help me out here.
> >
> > *I have enable: debug mpls packet on all IOS routers and found out that
> > the path from R10 to R8 is okay the ICMP packets arrived at R8*
> >
> > R10#ping 8.8.8.8 source lo 1
> >
> > Type escape sequence to abort.
> >
> > Sending 5, 100-byte ICMP Echos to 8.8.8.8, timeout is 2 seconds:
> >
> > Packet sent with a source address of 10.10.10.10
> >
> > .....
> >
> > Success rate is 0 percent (0/5)
> >
> >
> >
> > R8#
> >
> > *May 15 08:38:12.787: ICMP: echo reply sent, src 8.8.8.8, dst
> 10.10.10.10,
> > topology BASE, dscp 0 topoid 0
> >
> > R8#
> >
> > *May 15 08:38:14.787: ICMP: echo reply sent, src 8.8.8.8, dst
> 10.10.10.10,
> > topology BASE, dscp 0 topoid 0
> >
> > R8#
> >
> > *May 15 08:38:16.789: ICMP: echo reply sent, src 8.8.8.8, dst
> 10.10.10.10,
> > topology BASE, dscp 0 topoid 0
> >
> > R8#
> >
> > *May 15 08:38:18.794: ICMP: echo reply sent, src 8.8.8.8, dst
> 10.10.10.10,
> > topology BASE, dscp 0 topoid 0
> >
> > R8#
> >
> > *May 15 08:38:20.793: ICMP: echo reply sent, src 8.8.8.8, dst
> 10.10.10.10,
> > topology BASE, dscp 0 topoid 0
> >
> > R8#
> >
> >
> >
> > *At the debug mpls packet on R6 I can see the traffic returning from R8,
> > XR2 did not send a transport label*
> >
> > R6#
> >
> > *May 15 08:40:33.025: MPLS les: Et0/0.196: rx: Len 1514 Stack {16 0 251}
> > {16001 0 254} - ipv4 data s:10.10.10.10 d:8.8.8.8 ttl:254 tos:0 prot:1
> >
> > *May 15 08:40:33.025: MPLS les: Et0/0.206: tx: Len 1510 Stack {16001 0
> 250}
> > - ipv4 data s:10.10.10.10 d:8.8.8.8 ttl:254 tos:0 prot:1
> >
> > *May 15 08:40:33.027: MPLS les: Et0/0.206: rx: Len 1514 Stack {25 0 254}
> -
> > ipv4 data s:8.8.8.8 d:10.10.10.10 ttl:254 tos:0 prot:1
> >
> > R6#
> >
> > *May 15 08:40:35.027: MPLS les: Et0/0.196: rx: Len 1514 Stack {16 0 251}
> > {16001 0 254} - ipv4 data s:10.10.10.10 d:8.8.8.8 ttl:254 tos:0 prot:1
> >
> > *May 15 08:40:35.027: MPLS les: Et0/0.206: tx: Len 1510 Stack {16001 0
> 250}
> > - ipv4 data s:10.10.10.10 d:8.8.8.8 ttl:254 tos:0 prot:1
> >
> > *May 15 08:40:35.029: MPLS les: Et0/0.206: rx: Len 1514 Stack {25 0 254}
> -
> > ipv4 data s:8.8.8.8 d:10.10.10.10 ttl:254 tos:0 prot:1
> >
> >
> >
> > *When I look into the vpnv4 table on XR2 I can see it is using a VPN
> label
> > 25 with a next-hop of 2.2.2.2*
> >
> > RP/0/0/CPU0:XR2#sh bgp vpnv4 unicast vrf A 10.10.10.10
> >
> > BGP routing table entry for 10.10.10.10/32, Route Distinguisher: 100:1
> >
> > Versions:
> >
> > Process bRIB/RIB SendTblVer
> >
> > Speaker 337 337
> >
> > Local Label: 16009
> >
> > Last Modified: May 14 07:23:21.885 for 00:03:37
> >
> > Paths: (1 available, best #1)
> >
> > Advertised to peers (in unique update groups):
> >
> > 5.5.5.5
> >
> > Path #1: Received by speaker 0
> >
> > Advertised to peers (in unique update groups):
> >
> > 5.5.5.5
> >
> > 1
> >
> > 2.2.2.2 (metric 1) from 2.2.2.2 (2.2.2.2)
> >
> > Received Label 25
> >
> > Origin incomplete, localpref 100, valid, external, best,
> group-best,
> > import-candidate, imported
> >
> > Received Path ID 0, Local Path ID 1, version 337
> >
> > Extended community: OSPF domain-id:0x5:0x000000020200 OSPF
> > route-type:0:2:0x0 OSPF router-id:10.10.104.4 RT:100:1
> >
> > Source VRF: A, Source Route Distinguisher: 100:1
> >
> > RP/0/0/CPU0:XR2#
> >
> >
> >
> > *When I look into the forwarding table I noticed that destination 2.2.2.2
> > has pop as outgoing label to 6.6.6.6 so it indeed does not send a
> > transport label. This is what I cannot figure out why this is*
> >
> > RP/0/0/CPU0:XR2#sh mpls forwarding
> >
> > Wed May 14 07:29:50.367 UTC
> >
> > Local Outgoing Prefix Outgoing Next Hop Bytes
> >
> > Label Label or ID Interface
> Switched
> >
> > ------ ----------- ------------------ ------------ ---------------
> > ------------
> >
> > 16000 Aggregate A: Per-VRF Aggr[V] A 0
> >
> > 16001 Unlabelled 8.8.8.8/32[V] Gi0/0/0/0.208 10.10.208.8
> 81840
> >
> > 16002 Pop 6.6.6.6/32 Gi0/0/0/0.206 10.10.206.6 6830
> >
> > 16003 Pop 10.10.56.0/24 Gi0/0/0/0.206 10.10.206.6 0
> >
> > 16004 Pop 10.10.196.0/24 Gi0/0/0/0.206 10.10.206.6 0
> >
> > 16005 18 5.5.5.5/32 Gi0/0/0/0.206 10.10.206.6 7370
> >
> > 16006 17 19.19.19.19/32 Gi0/0/0/0.206 10.10.206.6 0
> >
> > 16007 Pop 2.2.2.2/32 Gi0/0/0/0.206 10.10.206.6 3215
> >
> > 16008 20 4.4.4.4/32 Gi0/0/0/0.206 10.10.206.6 4860
> >
> > 16009 25 10.10.10.10/32[V] 2.2.2.2 1040
> >
> > 16010 26 10.10.104.0/24[V] 2.2.2.2 0
> >
> > 16011 21 100:2:10.10.115.0/24 \
> >
> > 5.5.5.5 0
> >
> > 16012 22 100:2:11.11.11.11/32 \
> >
> > 5.5.5.5 0
> >
> > 16013 23 100:3:10.10.125.0/24 \
> >
> > 5.5.5.5 0
> >
> > 16014 24 100:3:12.12.12.12/32 \
> >
> > 5.5.5.5 0
> >
> > *When I look into R6 MPLS forwarding table it does not say it is local
> but
> > has a local label of 19 (so why is XR2 not have label 19 into its
> > forwarding table)*
> >
> > R6#sh mpls forwarding-table
> >
> > Local Outgoing Prefix Bytes Label Outgoing Next Hop
> >
> > Label Label or Tunnel Id Switched interface
> >
> > 16 Pop Label 20.20.20.20/32 96772 Et0/0.206
> > 10.10.206.20
> >
> > 17 Pop Label 19.19.19.19/32 0 Et0/0.196
> > 10.10.196.19
> >
> > 18 Pop Label 5.5.5.5/32 9229 Et0/0.56
> 10.10.56.5
> >
> > 19 16000 2.2.2.2/32 36336 Et0/0.196
> > 10.10.196.19
> >
> > 20 16001 4.4.4.4/32 68130 Et0/0.196
> > 10.10.196.19
> >
> >
> >
> > *I have cleared all process even reloaded all routers but this did not
> help
> > *
> >
> > *After that I decided to configure the next-hop unchanged command on the
> > route reflectors and somehow this fixed the issue for VRF A to make it
> work
> > for the other VRFb s I needed to redistribute the other PE loopbacks into
> > the core IGP so they would also receive labels. This change also changed
> > the MPLS forwarding table on XR2 in such way that it had a label for R2.
> I
> > cannot related the next-hop unchanged feature to changing the LDP
> behavior
> > it only ensures it does not change the next hop to its own address. Below
> > is the BGP configuration of XR2*
> >
> > RP/0/0/CPU0:XR2#sh runn router bgp
> >
> > Wed May 14 07:36:07.721 UTC
> >
> > router bgp 2
> >
> > address-family ipv4 unicast
> >
> > !
> >
> > address-family vpnv4 unicast
> >
> > !
> >
> > neighbor 2.2.2.2
> >
> > remote-as 1
> >
> > ebgp-multihop 255
> >
> > update-source Loopback1
> >
> > address-family vpnv4 unicast
> >
> > route-policy PASS in
> >
> > route-policy PASS out
> >
> > !
> >
> > !
> >
> > neighbor 5.5.5.5
> >
> > remote-as 2
> >
> > update-source Loopback1
> >
> > address-family vpnv4 unicast
> >
> > route-policy PASS in
> >
> > route-reflector-client
> >
> > route-policy PASS out
> >
> > !
> >
> > !
> >
> > vrf A
> >
> > rd 100:1
> >
> > address-family ipv4 unicast
> >
> > redistribute ospf main
> >
> > !
> >
> > !
> >
> > !
> >
> > * When at the XR2 MPLS forwarding table it is different then the mpls ldp
> > forwarding table. I caanot indetify where the pop label comes from in the
> > mpls forwarding table. The mpls LDP forwarding table and binding table
> > shows the correct label. The router however installes a pop label into
> the
> > mpls forwarding table.*
> >
> > RP/0/0/CPU0:XR2#sh mpls ldp forwarding
> > Wed May 14 12:58:52.225 UTC
> >
> > Codes:
> > - = GR label recovering, (!) = LFA FRR pure backup path
> > {} = Label stack with multi-line output for a routing path
> > G = GR, S = Stale, R = Remote LFA FRR backup
> >
> > Prefix Label Label(s) Outgoing Next Hop
> > Flags
> > In Out Interface
> G S
> > R
> > --------------- ------- -------------- ------------ -------------------
> > -----
> > 2.2.2.2/32 16007 19 Gi0/0/0/0.206 10.10.206.6
> > 4.4.4.4/32 16008 20 Gi0/0/0/0.206 10.10.206.6
> > 5.5.5.5/32 16005 18 Gi0/0/0/0.206 10.10.206.6
> > 6.6.6.6/32 16002 ImpNull Gi0/0/0/0.206 10.10.206.6
> > 10.10.56.0/24 16003 ImpNull Gi0/0/0/0.206 10.10.206.6
> > 10.10.196.0/24 16004 ImpNull Gi0/0/0/0.206 10.10.206.6
> > 19.19.19.19/32 16006 17 Gi0/0/0/0.206 10.10.206.6
> >
> >
> > XR2 has no labels within BGP for ipv4 only for vpnv4. It the option C
> > example in the stage where R2 and XR2 still does not have the next-hop
> > unchange feature enabled and the traffic should flow via XR2 and R2 BGP
> > labels are only exchange between XR1 and R1. XR1 is redistributing the
> > routes into the IGP (OSPF in this case) because it is the IGP LDP should
> > generate the labels so XR2 should have the label from LDP and it has only
> > it does not install them.
> >
> >
> > Also the strange thing if I also distribute R4b s loopback with the same
> > technology it does have a label from LDP only R2 show strange behavior
> > which I cannot clarify.
> >
> >
> >
> > RP/0/0/CPU0:XR2#sh mpls forwarding
> >
> > Thu May 15 09:56:26.496 UTC
> >
> > Local Outgoing Prefix Outgoing Next Hop Bytes
> >
> > Label Label or ID Interface
> Switched
> >
> > ----- ----------- ------------------ ------------ ---------------
> > ------------
> >
> > 16001 Unlabelled 8.8.8.8/32[V] Gi0/0/0/0.208 10.10.208.8 7440
> >
> > 16002 Pop 6.6.6.6/32 Gi0/0/0/0.206 10.10.206.6
> 146640
> >
> > 16003 17 19.19.19.19/32 Gi0/0/0/0.206 10.10.206.6 0
> >
> > 16004 Pop 10.10.196.0/24 Gi0/0/0/0.206 10.10.206.6 0
> >
> > 16005 Pop 2.2.2.2/32 Gi0/0/0/0.206 10.10.206.6
> 133952
> >
> > 16006 Pop 10.10.56.0/24 Gi0/0/0/0.206 10.10.206.6 0
> >
> > 16007 19 5.5.5.5/32 Gi0/0/0/0.206 10.10.206.6
> 180691
> >
> > *16008 18 4.4.4.4/32 <http://4.4.4.4/32> Gi0/0/0/0.206
> > 10.10.206.6 0*
> >
> > 16009 Aggregate A: Per-VRF Aggr[V] A 0
> >
> > 16010 22 100:2:10.10.115.0/24 \
> >
> > 5.5.5.5 0
> >
> > 16011 23 100:2:11.11.11.11/32 \
> >
> > 5.5.5.5 0
> >
> > 16012 24 100:3:10.10.125.0/24 \
> >
> > 5.5.5.5 0
> >
> > 16013 25 100:3:12.12.12.12/32 \
> >
> > 5.5.5.5 52220
> >
> > 16014 25 10.10.10.10/32[V] 2.2.2.2 7280
> >
> > 16015 26 10.10.104.0/24[V] 2.2.2.2 0
> >
> >
> >
> >
> > Can you please help me clear this up.Thanks in advance
> >
> >
> >
> > Maarten Vervoorn
> >
> >
> > Blogs and organic groups at http://www.ccie.net
> >
> > _______________________________________________________________________
> > Subscription information may be found at:
> > http://www.groupstudy.com/list/CCIELab.html
>
>
> Blogs and organic groups at http://www.ccie.net
>
> _______________________________________________________________________
> Subscription information may be found at:
> http://www.groupstudy.com/list/CCIELab.html

Blogs and organic groups at http://www.ccie.net
Received on Thu Jun 05 2014 - 12:44:22 ART