SR SRTE PCE Hands On - LACNIC...Segment Routing Configuration Example –OSPF 27 router ospf1...

LACNIC32 / LACNOG 2019

SR+SRTE+PCE

© 2018 C isco and/or its affiliates. A ll r ights reserved. C isco Confidential

Agenda

1

2

4

3

5

Segment Routing Recap

Segment Routing Traffic Engineer Fundamentals

SR + SRTE + PCE Configuration

PCE based SRTE Policy Architecture

Lab : SR + Basic SRTE + PCE


Agile + DevOps

Simplify Automate Virtualize Program

New business capabilities built on the network as the platform;Enabling customers to achieve business outcomes faster with ruthless

ease

What everyone agrees SP (and everyone else) should do … more or less …


24123

16001

16002

16003

16004

16005

16006

24010

24012

24024

24034

24035

24045

24010

Node SID (Prefix SID) Adjacency SID

Globally Significant Locally SignificantUnidirectional

Binding SID Peering SID (EPE)

Globally or Locally Significant Locally Significant

Anycast SID

Globally Significant

Segment Routing – Technology Overview


IGP Prefix Segment

• Shortest-path to the IGP prefix– Equal Cost MultiPath (ECMP)-aware

• Global Segment

• Label = 16000 + Index– Advertised as index

• Distributed by ISIS/OSPF

1 2

3 4

516004

16004

16004

16004

16004

16004

160041.1.1.4/32

All nodes use default SRGB16,000 – 23,999


IGP Adjacency Segment

• Forward on the IGP adjacency

• Local Segment

• Advertised as label value

• Distributed by ISIS/OSPF1 2

3 4

524024

24025Adj to 5

Adj to 4

All nodes use default SRGB16,000 – 23,999


Anycast Prefix Segment

• Same prefix advertised by multiple nodes

• Traffic is forwarded to one of the Anycastprefix-SIDs based on best IGP path

• If primary node fails, traffic is auto re-routed to the other node

DC (BGP-SR)

10

11

12

13

14

2 4

6 5

7

WAN (IGP-SR)

3

1

PEER

16100

100

100


Binding-SID (BSID) is fundamental• The BSID of the SR Policy selected path is installed in the forwarding table

• Binding Segment is a fundamental building block of SRTE

• The Binding Segment is a local segment

• Each SRTE Policy is associated 1-for-1 with a Binding-SID

• Remote steering– A packet arriving on the SR Policy head-end with

the BSID as Active Segment (top of label stack) is steered into the SR Policy associated with the BSID

• Local steering– A packet that matches a forwarding entry that

resolves on the BSID of an SR Policy is steered into that SR Policy

BSID SID-list

BSID

Prefix

SID-list


Segment Routing – Technology Overview

Globally unique Prefix-SID identifies the router

Locally unique Adjacency-SID identifies link on a router

Simple extension to IS-IS or OSPF to propagate SIDs through the network

SID is used as label in MPLS-SR

Builds & Maintains ”Segment”


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Segment Routing TE Fundamentals


Different ways to instantiation on Headend

Traffic Steered into policy by using “Color”

Interact with Applications for network transport programmability

“SRTE Policy” - No more tunnels

SRTE Ground Rules

Policy Instantiation

New CLI Construct

Automated Steering

External Path Computation


SRTE Policy Identification

• An SR policy is uniquely identified by a tuple

Where the SR Policy is instantiated (implemented)Head End

Numeric value to differentiate multiple SRTE Policies between the same pair of nodesColor

Destination of the SR PolicyEndpoint

H

C

E


16001

16002

16003

16004

16005

16006

24010

24012

24024

24034

24035

24045

24010

H C E

RedGreenBlue

SRTE Policy Identification


R6

R1 R2

R3

R4 R5

Data22002

Data16003

Data24034

Data

R1 R2

R3

R4 R5

Data

1600416005

Data

1600416005

Data16005

Data

INOUT: 22002

Data

Data

T: 100IN: 16005

OUT

T: 100IN: 22002OUT: 16003

T: 100IN: 16003OUT: 24034

T: 100

IN: 24034OUT: 16005

T: 100

16005

SR Tunnel Path

RSVP Tunnel Path

16004 16005

R6

16003

Data

1600416005

RSVP-TE vs SR-TE Tunnels

R7

R7

Data

Desired Path: R3-R4-R5

16003 16003


R1 R2

R3

R4 R5

Data1600516004

Data

1600416005

Data16005

DataDataSR Tunnel

Path

16004 16005

R6

16003

Data1600516004

SR-TE Tunnels Benefits

R7

Implicitly able to use ECMP

Using lable stack, full TE path

programmed at source (SDN

friendly!)

No Additional state maintained in Mid-Point (Scalability!!)

SR-TE RSVP-TE

TE state only at head-end Yes No

Engineered for SDN Yes Yes/No

ECMP-capability for TE Yes No


© 2019 Cisco and/or its affiliates. All rights reserved. Cisco Public

SRTE Policy

18

SRTE Policy Cpath 2, Pref YBinding SID

Cpath 1, Pref X

Binding SID

SID-List 1-1

Weigh 1-1

SID-List 1-2

Weigh 1-2

SID-List 2-1

Weigh 2-1

• Identified by Unique: (Head-End + Color + End-Point)

• Chosen based on Preference• Valid if: Any of the SID-list is valid• Identified by: Binding SID (Auto)

• Programmed in FIB simultaneously

• Load-balanced based on• Weight

Learnt from: • Explicit Local• Dynamic Local• Dynamic PCE


Agenda

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Centralized Control for SRTE – Building Blocks

Centralized Knowledge of IGP Database

• IGP Database knowledge contained in IGP domains

• IGP DB is Distributed into new BGP NLRI

• BGP Carries the information to Central Controller

BGP Link State (BGP-LS)

Path Computation Element Protocol (PCEP)

Segment Routing Path Computation Element (SR PCE)

20



BGP Link State - Overview

• Build TE-DB for Multi-area Optimal Path Computation

• Scalable Solution is BGP, not IGP.

• BGP is less chatty

• Can carry multiple IGP domains

• BGP-LS is an address-family • afi=16388, safi=71

• Defined to carry IGP link-state database via BGP• Supports both IS-IS and OSPF• Delivers topology information to outside agents

21

TEDB

SR-PCE

BGP-LS

BGP-LS BGP-LS

RR



SR PCE Implementation

• SR PCE runs as IOS XR feature• deployed as a virtual machine (VM) instance on x86 server

• UCS server recommended

• Virtual device Cisco IOS XR XRv 9000• XRV9000 image• VRR License + SR-PCE License

22

2801

Physical HW (x86)HyperVisor

IOS XRv 9000

Path computation algorithm is the SAME for Headend and PCE.However SR-PCE may offer a broader view and additional North bound capabilities


Agenda

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SR + SRTE + PCE Configurations




SR + SRTE + PCE Configurations


• Configured under IGP Routing Protocol

• Requires: Enabling SR & Configuring Prefix-SID• Configure “Absolute Value” or “Index”

• Optional: Configure SR-Global-Block (SRGB). • Default 16000 – 23999 (higher in newer versions)

• SRGB & Index advertised using IGP

• Result: No LDP Needed for label distribution

Segment Routing – Configuration Concepts

16000 4 16004

SRGB Index SID



Segment Routing Configuration Example – ISIS

26

router isis 1address-family ipv4 unicastmetric-style widesegment-routing mpls sr-prefer!interface Loopback0passiveaddress-family ipv4 unicastprefix-sid index 1

!

Wide Metrics

enable SR IPv4 control plane and SR MPLS data plane on all ipv4

interfaces in this IS-IS instance

Ipv4 Prefix-SID value for loopback0(Index translate to 16001 absolute

value)



Segment Routing Configuration Example – OSPF

27

router ospf 1router-id 1.1.1.1segment-routing mplsarea 0interface Loopback0passive enableprefix-sid index 1!!!

enable SR IPv4 control plane and SR MPLS data plane on all ipv4

interfaces in this IS-IS instance

Ipv4 Prefix-SID value for loopback0(Index translate to 16001 absolute

value)



Segment Routing Configuration Example

28

segment-routingtraffic-engpolicy POLICY1color 20 end-point ipv4 1.1.1.4binding-sid mpls 1000candidate-pathspreference 100dynamic mplsmetrictype teaffinityexclude-any red

!preference 50explicit segment-list SIDLIST1

!segment-list name SIDLIST1index 10 mpls label 16002index 20 mpls label 30203index 30 mpls label 16004

Enable SRTE

Local Configured SRTE Policy

Color (C) & End-Point (E)

Binding SID for Selected C-Path

Candidate Path List

Candidate Path Preference


SR-PCE Configuration


Redistribute IGP Link State

router isis 100net 49.1921.5500.0004.00distribute link-state

Advertise via BGP-LSrouter bgp 65000address-family link-state link-stateneighbor 192.168.0.15remote-as 65000update-source Loopback0address-family ipv4 unicast!address-family link-state link-stateroute-reflector-client

Metro Area 01 Metro Area 02Core Network

C1

AppsAppsSR-PCE

ABR ABR

IS-IS Level 1 IS-IS Level 1IS-IS Level 2

BGP Link State Configuration Sample


PCEP Client and Server Configuration

PCE Client Configuration

segment-routingtraffic-engpcc

source-address ipv4 6.1.1.1pce address ipv4 6.1.1.100 precedence 100

PCE Server Configuration

pceaddress ipv4 6.1.1.100 à Enable PCE Serverrest à Option, Enable Application Access

peer ipv4 6.1.1.1 à Optional, required for Remote SR Policy Instantiation

Metro Area 01 Metro Area 02Core Network

C1

AppsAppsSR-PCE

ABR ABR

IS-IS Level 1 IS-IS Level 1IS-IS Level 2


PCE Computed or Instantiated SR Policy Example

Head End Configured, PCE Computed SR Policy Example*

segment-routingtraffic-engpolicy 25color 25 end-point ipv4 192.168.0.15candidate-pathspreference 100dynamicpcepmetric te (could be IGP or Delay as well)

segment-routingtraffic-engon-demand color 25dynamicmetrictype te

PCE Instantiated SR Policy Example *

pcesegment-routingtraffic-engpeer ipv4 192.168.0.25policy 25color 25 end-point ipv4 192.168.0.15candidate-pathspreference 100dynamic mplsmetrictype igp

RP/0/0/CPU0:PE25#sh segment-routing traffic-eng policyName: pcep_25 (Color: 25, End-point: 192.168.0.15)

Status:Admin: up Operational: up for 00:01:44

Candidate-paths:Auto-policy info:

Creator: PCEP


Agenda

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Segment Routing Traffic Engineer Basics





Lab Topology Overview

6.1.1.1

R1

R2

R3

R4

R5

R6

R7

R8

R9

R10

SR-PCE1 RR

G0/0 G0/0

G0/0

G0/0G0/0

G0/1

G0/0

G0/0

G0/0 G0/0G0/

0G0/0

G0/7 G0/5

G00

G0/1

G0/1

G0/1

G0/1

G0/1

G0/1

G0/1

G0/1

G0/1G0/3

G0/2

G0/2

G0/2

G0/2

G0/2

G0/2

G0/2

G0/2

G0/5

G0/3

G0/3

G0/3

G0/3 G0/3

G0/3

G0/3

G0/4

G0/4 G0/5

6.1.1.10

6.1.1.2

6.1.1.3 6.1.1.7 6.1.1.9

6.1.1.6 6.1.1.8

6.1.1.100

Next Hop SelfNext Hop Self

6.1.1.101

6.1.1.4


E2E (R1 ßà R10) L3VPN Service

R1

R2

R3

R4

R5

R6

R7

R8

R9

R10

XTC2

XTC1 RR

G0/0 G0/0

G0/0

G0/0G0/0

G0/0

G0/0

G0/0

G0/0

G0/0 G0/0

G0/0

G0/0

G0/6

G0/7 G0/6

G0/1

G0/1

G0/1

G0/1

G0/1

G0/1

G0/1

G0/1

G0/1

G0/1G0/3

G0/2

G0/2

G0/2

G0/2

G0/2

G0/2

G0/2

G0/2

G0/5

G0/3

G0/3

G0/3

G0/3 G0/3

G0/3

G0/3

G0/4

G0/4 G0/5

6.1.1.2

6.1.1.3 6.1.1.7 6.1.1.9

6.1.1.6 6.1.1.8

6.1.1.100

6.1.1.102

6.1.1.101

CoreISIS L2

AccessISIS L1

AccessISIS L1

int gig 0/0/0/2vrf C-Blueipv4 address 2.0.0.6 /24

int gig 0/0/0/2vrf C-Blueipv4 address 1.0.0.6 /24

6.1.1.1 6.1.1.10


• Notice that we don’t have connectivity between R1 and R10.

• The purpose of this lab exercise is to establish this connectivity using SR-MPLS End to End

Task 1: Check ISIS Routing Table

RP/0/0/CPU0:R1#sh route ipv4 | in 6.1.1.L 6.1.1.1/32 is directly connected, 23:54:08, Loopback0i L1 6.1.1.2/32 [115/10] via 192.1.2.2, 23:53:59, GigabitEthernet0/0/0/1i L1 6.1.1.3/32 [115/10] via 192.1.3.3, 23:53:59, GigabitEthernet0/0/0/0i L1 6.1.1.4/32 [115/20] via 192.1.3.3, 23:53:59, GigabitEthernet0/0/0/0i L1 6.1.1.5/32 [115/20] via 192.1.3.3, 23:53:59, GigabitEthernet0/0/0/0i ia 6.1.1.101/32 [115/30] via 192.1.3.3, 23:49:40, GigabitEthernet0/0/0/0i ia 6.1.1.102/32 [115/30] via 192.1.3.3, 23:47:39, GigabitEthernet0/0/0/0

RP/0/0/CPU0:R10#sh route ipv4 | in 6.1.1.i L1 6.1.1.6/32 [115/20] via 192.8.10.8, 23:43:15, GigabitEthernet0/0/0/0i L1 6.1.1.7/32 [115/20] via 192.8.10.8, 23:43:15, GigabitEthernet0/0/0/0i L1 6.1.1.8/32 [115/10] via 192.8.10.8, 23:43:15, GigabitEthernet0/0/0/0i L1 6.1.1.9/32 [115/10] via 192.9.10.9, 23:43:15, GigabitEthernet0/0/0/1L 6.1.1.10/32 is directly connected, 23:43:24, Loopback0i ia 6.1.1.101/32 [115/40] via 192.8.10.8, 23:43:15, GigabitEthernet0/0/0/0i ia 6.1.1.102/32 [115/40] via 192.8.10.8, 23:43:15, GigabitEthernet0/0/0/0

RP/0/0/CPU0:R1#ping 6.1.1.10 source 6.1.1.1Type escape sequence to abort.Sending 5, 100-byte ICMP Echos to 6.1.1.10, timeout is 2 seconds:.....Success rate is 0 percent (0/5)

RP/0/0/CPU0:R1#ping vrf C-Blue 2.0.0.6Type escape sequence to abort.Sending 5, 100-byte ICMP Echos to 2.0.0.6, timeout is 2 seconds:.....Success rate is 0 percent (0/5)


Task 2: Check MPLS/LDP/L3VPN forwarding plane

RP/0/0/CPU0:R1#sh mpls forLocal Outgoing Prefix Outgoing Next HopLabel Label or ID Interface------ ----------- ------------------ ------------ ---------------24000 Aggregate C-Blue: Per-VRF Aggr[V] \

C-Blue24001 Unlabelled 6.1.1.101/32 Gi0/0/0/0 192.1.3.3

Unlabelled 6.1.1.101/32 Gi0/0/0/1 192.1.2.224002 Unlabelled 6.1.1.102/32 Gi0/0/0/0 192.1.3.3

Unlabelled 6.1.1.102/32 Gi0/0/0/1 192.1.2.2

RP/0/0/CPU0:R10#sh mpls forLocal Outgoing Prefix Outgoing Next HopLabel Label or ID Interface------ ----------- ------------------ ------------ ---------24000 Unlabelled 6.1.1.101/32 Gi0/0/0/0 192.8.10.8

Unlabelled 6.1.1.101/32 Gi0/0/0/1 192.9.10.924001 Unlabelled 6.1.1.102/32 Gi0/0/0/0 192.8.10.8

Unlabelled 6.1.1.102/32 Gi0/0/0/1 192.9.10.924002 Aggregate C-Blue: Per-VRF Aggr[V] \

C-Blue

R1

R2

R3

R4

R5

R6

R7

R8

R9

R10

AccessISIS L1

AccessISIS L1

CoreISIS L2

RP/0/0/CPU0:R1#sh bgp vpnv4 unicast

Network Next Hop Metric LocPrf Weight PathRoute Distinguisher: 65000:1 (default for vrf C-Blue)*> 1.0.0.0/24 0.0.0.0 0 32768 ?* i2.0.0.0/24 6.1.1.10 0 100 0 ?* i 6.1.1.10 0 100 0 ?


Network Next Hop Metric LocPrf Weight PathRoute Distinguisher: 65000:1 (default for vrf C-Blue)* i 1.0.0.0/24 6.1.1.1 0 100 0 ?* i 6.1.1.1 0 100 0 ?*> 2.0.0.0/24 0.0.0.0 0 32768 ?


R1

R2

R3

R4

R5

R6

R7

R8

R9

R10Core

ISIS L2Access

ISIS L1Access

ISIS L1

R1 Configuration

segment-routingglobal-block 16000 17000

router isis 100address-family ipv4 unicastsegment-routing mpls sr-prefer

router isis 100interface Loopback0address-family ipv4 unicastprefix-sid index 1

R10 Configuration

segment-routingglobal-block 16000 17000

router isis 100address-family ipv4 unicastsegment-routing mpls sr-prefer

router isis 100interface Loopback0address-family ipv4 unicastprefix-sid index 10

RP/0/0/CPU0:R2#sh mpls forLocal Outgoing Prefix Outgoing Next Hop BytesLabel Label or ID Interface Switched------ ----------- ------------------ ------------ --------------- ---------16003 Pop SR Pfx (idx 3) Gi0/0/0/2 10.0.0.14 016004 Pop SR Pfx (idx 4) Gi0/0/0/0 10.0.0.18 177600016005 Pop SR Pfx (idx 5) Gi0/0/0/1 10.0.0.22 482035024000 Pop SR Adj (idx 0) Gi0/0/0/1 10.0.0.22 024001 Pop SR Adj (idx 2) Gi0/0/0/1 10.0.0.22 024008 Pop SR Adj (idx 0) Gi0/0/0/3 198.18.2.31 024009 Pop SR Adj (idx 2) Gi0/0/0/3 198.18.2.31 024010 Pop SR Adj (idx 0) Gi0/0/0/2 10.0.0.14 0

Task 3: Enable SR, Configure Prefix SID


RP/0/0/CPU0:R1# sh cef 6.1.1.4

6.1.1.4/32, version 325, labeled SR, internal 0x1000001 0x83 (ptr0xde09540) [1], 0x0 (0xdfce3a8), 0xa28 (0xee090f0)Updated Feb 17 00:31:47.949remote adjacency to GigabitEthernet0/0/0/0Prefix Len 32, traffic index 0, precedence n/a, priority 1

via 198.18.2.70/32, GigabitEthernet0/0/0/0, 6 dependencies, weight 0, class 0 [flags 0x0]

path-idx 0 NHID 0x0 [0xeb76bf0 0x0]next hop 198.18.2.70/32remote adjacencylocal label 16004 labels imposed {16004}

via 198.18.3.70/32, GigabitEthernet0/0/0/1, 6 dependencies, weight 0, class 0 [flags 0x0]

path-idx 1 NHID 0x0 [0xeb76c80 0x0]next hop 198.18.3.70/32remote adjacencylocal label 16004 labels imposed {16004}

RP/0/RP0/CPU0:R1#traceroute sr-mpls 6.1.1.4/32 source 6.1.1.10 198.18.3.31 MRU 1500 [Labels: 16004 Exp: 0]L 1 198.18.3.70 MRU 1500 [Labels: implicit-null Exp: 0] 18 ms! 2 10.0.0.30 15 ms

RP/0/0/CPU0:R1# sh mpls forwardingSun Feb 17 00:32:31.065 UTC

Local Outgoing Prefix Outgoing Next HopLabel Label or ID Interface------ ----------- ------------------ ------------ --------------- --16002 Pop SR Pfx (idx 2) Gi0/0/0/1 192.1.2.2 0 16003 Pop SR Pfx (idx 3) Gi0/0/0/0 192.1.3.3 0 16004 16004 SR Pfx (idx 4) Gi0/0/0/0 192.1.3.3 0

16004 SR Pfx (idx 4) Gi0/0/0/1 192.1.2.2 0 16005 16005 SR Pfx (idx 5) Gi0/0/0/0 192.1.3.3 0



16102 SR Pfx (idx 102) Gi0/0/0/1 192.1.2.2 0 24000 Aggregate C-Blue: Per-VRF Aggr[V] \

C-Blue 0 24001 Pop SR Adj (idx 0) Gi0/0/0/1 192.1.2.2 0 24002 Pop SR Adj (idx 2) Gi0/0/0/1 192.1.2.2 0 24003 Pop SR Adj (idx 0) Gi0/0/0/0 192.1.3.3 0 24004 Pop SR Adj (idx 2) Gi0/0/0/0 192.1.3.3 0

Task 4: Verify SR Forwarding Table



Network Next Hop Metric LocPrf Weight PathRoute Distinguisher: 65000:1 (default for vrf C-Blue)*> 1.0.0.0/24 0.0.0.0 0 32768 ?* i2.0.0.0/24 6.1.1.10 0 100 0 ?

RP/0/0/CPU0:R1#sh route vrf C-Blue

C 1.0.0.0/24 is directly connected, 1d02h, Gig/0/0/0/2L 1.0.0.6/32 is directly connected, 1d02h, Gig 0/0/0/2


Network Next Hop Metric LocPrf Weight PathRoute Distinguisher: 65000:1 (default for vrf C-Blue)* i 1.0.0.0/24 6.1.1.1 0 100 0 ?*> 2.0.0.0/24 0.0.0.0 0 32768 ?

RP/0/0/CPU0:R10#sh route vrf C-Blue

C 2.0.0.0/24 is directly connected, 1d02h, Gig/0/0/0/2L 2.0.0.6/32 is directly connected, 1d02h, Gig 0/0/0/2

RP/0/0/CPU0:R1#ping 6.1.1.10 source 6.1.1.1Type escape sequence to abort.Sending 5, 100-byte ICMP Echos to 6.1.1.10, timeout is 2 seconds:.....Success rate is 0 percent (0/5)

RP/0/0/CPU0:R1#ping vrf C-Blue 2.0.0.6Type escape sequence to abort.Sending 5, 100-byte ICMP Echos to 2.0.0.6, timeout is 2 seconds:.....Success rate is 0 percent (0/5)

Task 5: VRF Connectivity


R1

R2

R3

R4

R5

R6

R7

R8

R9

R10Core

ISIS L2Access

ISIS L1Access

ISIS L1

RP/0/RP0/CPU0:R1#sh bgp vpnv4 unicastRoute Distinguisher: 65000:1 (default for vrf C-Blue)Network Next Hop Metric LocPrf Weight Path*> 1.0.0.0/24 0.0.0.0 0 32768 ?* i2.0.0.0/24 6.1.1.10 0 100 0 ?* i 6.1.1.10 0 100 0 ?

RP/0/RP0/CPU0:R1#sh bgp all all summaryAddress Family: VPNv4 Unicast-----------------------------

Neighbor Spk AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down St/PfxRcd6.1.1.4 0 65001 472 467 11 0 0 07:40:21 16.1.1.5 0 65001 474 467 11 0 0 07:40:20 1

Address Family: IPv4 Labeled-unicast------------------------------------Neighbor Spk AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down St/PfxRcd6.1.1.4 0 65001 472 467 16 0 0 07:40:21 26.1.1.5 0 65001 474 467 16 0 0 07:40:20 2

RR

SR-PCE2

SR-PCE1


R1

R2

R3

R4

R5

R6

R7

R8

R9

R10Core

ISIS L2Access

ISIS L1Access

ISIS L1

• We will configure R1 and R10 to advertise their loopbacks so that they both learn each other’s SR labels/SID through BGP.

• Once the configuration is done, did you notice the following message pop up on inline Route Reflectors (R4, R5, R6, R7)

SR-PCE2

R1 Configuration

router bgp 65001address-family ipv4 unicastnetwork 6.1.1.1/32allocate-label all

R10 Configuration

router bgp 65001address-family ipv4 unicastnetwork 6.1.1.10/32allocate-label all

RP/0/0/CPU0:R4#RP/0/0/CPU0:Feb 19 03:42:51.450 UTC: ipv4_rib[1154]: %ROUTING-RIB-3-LABEL_ERR_ADD : Add local-label 24014 (2) for table 0xe0000000, prefix 6.1.1.1/32, by proto bgp client 23 bgp node0_0_CPU0 - existing label 16001 added by proto-id 4 client 15

RP/0/0/CPU0:R6#RP/0/0/CPU0:Feb 19 03:47:28.142 UTC: ipv4_rib[1154]: %ROUTING-RIB-3-LABEL_ERR_ADD : Add local-label 24011 (2) for table 0xe0000000, prefix 6.1.1.10/32, by proto bgp client 20 bgp node0_0_CPU0 - existing label 16010 added by proto-id 7 client 22

Task 6.1: Configure BGP to Allocate labels for IPv4


• Check if R1 and R10 could see each other’s Loopbacks in BGP/Global routing table and subsequently “valid” VPN routes in VRF as well

On R1

RP/0/0/CPU0:R1#sh bgpNetwork Next Hop Metric LocPrf Weight Path*> 6.1.1.1/32 0.0.0.0 0 32768 i*>i6.1.1.10/32 6.1.1.4 0 100 0 i* i 6.1.1.5 0 100 0 i*>i6.1.1.101/32 6.1.1.4 0 100 0 i* i 6.1.1.5 0 100 0 i*>i6.1.1.102/32 6.1.1.4 0 100 0 i* i 6.1.1.5 0 100 0 i

On R10

RP/0/0/CPU0:R10# sh bgpNetwork Next Hop Metric LocPrf Weight Path*>i6.1.1.1/32 6.1.1.6 0 100 0 i* i 6.1.1.7 0 100 0 i*> 6.1.1.10/32 0.0.0.0 0 32768 i*>i6.1.1.101/32 6.1.1.6 0 100 0 i* i 6.1.1.7 0 100 0 i*>i6.1.1.102/32 6.1.1.6 0 100 0 i* i 6.1.1.7 0 100 0 i

On R1

RP/0/0/CPU0:R1# sh bgp vpnv4 unicastNetwork Next Hop Metric LocPrf Weight Path

Route Distinguisher: 65000:1 (default for vrf C-Blue)*> 1.0.0.0/24 0.0.0.0 0 32768 ?*>i2.0.0.0/24 6.1.1.10 0 100 0 ?* i 6.1.1.10 0 100 0 ?

On R10

RP/0/0/CPU0:R10# sh bgp vpnv4 unicastNetwork Next Hop Metric LocPrf Weight PathRoute Distinguisher: 65000:1 (default for vrf C-Blue)*>i1.0.0.0/24 6.1.1.1 0 100 0 ?* i 6.1.1.1 0 100 0 ?*> 2.0.0.0/24 0.0.0.0 0 32768 ?

Even though routes are valid, ping between vpn and “ping sr-mpls” between R1/R10 Loopbacks will fail. This is due to error message received on inline RRs in the previous step. Check next slide for more details

RP/0/0/CPU0:R1# ping sr-mpls 6.1.1.10/32 source 6.1.1.1Type escape sequence to abort.

NNNNNSuccess rate is 0 percent (0/5)

RP/0/0/CPU0:R10# ping sr-mpls 6.1.1.1/32 source 6.1.1.10Type escape sequence to abort.

NNNNNSuccess rate is 0 percent (0/5)


R1 Configurationroute-policy SID($SID)set label-index $SID

end-policy

router bgp 65001address-family ipv4 unicastnetwork 6.1.1.1/32 route-policy SID(1)allocate-label all

R10 Configurationroute-policy SID($SID)set label-index $SID

end-policy

router bgp 65001address-family ipv4 unicastnetwork 6.1.1.10/32 route-policy SID(10)allocate-label all

RP/0/RP0/CPU0:R4# sh bgp 6.1.1.1BGP routing table entry for 6.1.1.1/32Versions:Process bRIB/RIB SendTblVerSpeaker 15 15Local Label: 16001


R1

R2

R3

R4

R5

R6

R7

R8

R9

R10Core

ISIS L2Access

ISIS L1Access

ISIS L1

• Ping between R1 and R10, for MPLS as well as for L3VPN to check connectivity

R1 ßà R10 MPLS and L3VPN Service Verification (Expected to Pass Now)

RP/0/0/CPU0:R10#ping sr-mpls 6.1.1.1/32 source 6.1.1.10Sending 5, 100-byte MPLS Echos to 6.1.1.1/32,!!!!!

RP/0/0/CPU0:R10#ping vrf C-Blue 1.0.0.6Sending 5, 100-byte ICMP Echos to 1.0.0.6, timeout is 2 seconds:!!!!!

RP/0/RP0/CPU0:R1#ping sr-mpls 6.1.1.10/32 sou 6.1.1.1Sending 5, 100-byte MPLS Echos to 6.1.1.10/32,

timeout is 2 seconds, send interval is 0 msec:Type escape sequence to abort.!!!!!Success rate is 100 percent (5/5),

RP/0/RP0/CPU0:R1#ping vrf C-Blue 2.0.0.6

Sun Feb 17 01:24:38.600 UTCType escape sequence to abort.Sending 5, 100-byte ICMP Echos to 2.0.0.6, timeout is 2 sec!!!!!Success rate is 100 percent (5/5),

RP/0/RP0/CPU0:R1#traceroute sr-mpls 6.1.1.10/32 source 6.1.1.1

0 192.1.2.1 MRU 1500 [Labels: 16004/16010 Exp: 0/0]L 1 192.1.2.2 MRU 1500 [Labels: implicit-null/16010 Exp: 0/0] 6 msL 2 192.2.4.4 MRU 1500 [Labels: 16010 Exp: 0] 15 msL 3 192.4.7.7 MRU 1500 [Labels: 16010 Exp: 0] 16 ms. 4 *! 5 192.8.10.10 26 ms

Task 7: Connectivity


Segment Routing Traffic Engineering - Lab

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2

3

Configure & Validate BGP-LS

Configure PCE Server

Configure PCE Client-Server

Bringing it all together:Configure and Compute SRTE Policy Using SR-PCE


R1

R2

R3

R4

R5

R6

R7

R8

R9

R101

2

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6

5

4

3

10

SR-PCE2

SR-PCE1 RR

On R4,R5

router isis 100distribute link-state instance-id 101 level 1

router bgp 65001address-family link-state link-stateneighbor-group INLINE_RRCaddress-family link-state link-state

R4/R5 On R6,R7


router bgp 65001address-family link-state link-stateneighbor-group INLINE_RRCaddress-family link-state link-state

R6/R7

Make sure R4 and R5 distributes only L1 routers with instance-id

101

Make sure R6 and R7 distributes only L1 routers with instance-id

110

Instance-id is needed for SR-PCE to distinguish topologies belonging to different domains. Otherwise certain algorithms may operate incorrectly. Future SR-PCE releases may use ISIS domain-id for this purpose.

Task 8.1: Configure BGP LS on Routers


• Configure BGP-LS on all Route Reflectors (RR, R4, R5, R6, R7) and XTC (XTC1 and XTC2)

R1

R2

R3

R4

R5

R6

R7

R8

R9

R101

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6

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10

SR-PCE2

SR-PCE1 RR


router bgp 65001address-family link-state link-state!neighbor 6.1.1.100address-family link-state link-state

SR-PCE1/SR-PCE2

router bgp 65001address-family link-state link-stateneighbor-group RRCaddress-family link-state link-stateroute-reflector-client

neighbor 6.1.1.101use neighbor-group RRCneighbor 6.1.1.102use neighbor-group RRC

RR Config

Make sure SR-PCE distributes only L2 routers with instance-id

220SR-PCE ingests L2 toplogy directly, via distribute link-state directive. L1 topologies received via BGP-LS

RR should reflect BGP-LS AF to SR-PCEs

Task 8.2: Configure BGP LS on Routers


R1

R2

R3

R4

R5

R6

R7

R8

R9

R101

2

9

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6

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10

SR-PCE2

SR-PCE1 RR

RP/0/0/CPU0:SR-PCE1#sh bgp link-state link-state summary

Neighbor Spk AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down St/PfxRcd6.1.1.100 0 65001 2779 2635 209 0 0 00:02:17 122

SR-PCE1/SR-PCE2

RP/0/0/CPU0:RR#sh bgp link-state link-state summaryNeighbor Spk AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down St/PfxRcd6.1.1.4 0 65001 2834 2782 1075 0 0 00:04:44 616.1.1.5 0 65001 2839 2781 1075 0 0 00:04:42 616.1.1.6 0 65001 2841 2781 1075 0 0 00:04:42 616.1.1.7 0 65001 2842 2781 1075 0 0 00:04:42 616.1.1.101 0 65001 2637 2781 1075 0 0 00:04:44 06.1.1.102 0 65001 2636 2780 1075 0 0 00:04:44 0

RR

Task 9: BGP-LS on Router - Verify


• On one of SR-PCEs or RR use the following show commands for verification:• Show bgp link-state link-state• Show bgp link link [full route] (use one of the routes shown through above command)

• No TE attributes being advertised with the link-state information

Example Onlyshow bgp link link [E][L1][I0x65][N[c65001][b0.0.0.0][s1921.5500.0001.00]][R[c65001][b0.0.0.0][s1921.5500.0002.00]][L[i192.1.2.1][n192.1.2.2]]/696

Local

6.1.1.4 (metric 10) from 6.1.1.100 (6.1.1.4)Origin IGP, localpref 100, valid, internal, best, group-bestReceived Path ID 0, Local Path ID 1, version 259Originator: 6.1.1.4, Cluster list: 6.1.1.100Link-state: MSD: Type 1 Value 10, Remote TE Router-ID:

6.1.1.2 metric: 10, ADJ-SID: 24002(30) , Link Delay: 10 us Flags: 0x00Min Delay: 10 us Max Delay: 10 us Flags: 0x00, Delay Variation: 0 us

Task 10: BGP LS Advertise TE Attributes


• Configure on R1 and R10:

• Ensure that all the routers have this configuration (R1/R2/R3/R4/R5/R6/R7/R8/R9/R1/SR-PCE1/SR-PCE2) :

confrouter isis 100distribute link-state address-family ipv4 unicastmpls traffic-eng level-1-2mpls traffic-eng router-id Loopback0

commitend

Without TE information advertised along with the link-state in BGP-LS, SR-PCE won’t be able to compute policy paths

Task 10.1: Configure BGP LS Advertise TE Attributes


• Repeat show bgp link link command from 2 slides back

• Now TE attributes are being advertised with the link-state information

Example Onlyshow bgp link link [E][L1][I0x65][N[c65001][b0.0.0.0][s1921.5500.0001.00]][R[c65001][b0.0.0.0][s1921.5500.0002.00]][L[i192.1.2.1][n192.1.2.2]]/696

Local

6.1.1.4 (metric 10) from 6.1.1.100 (6.1.1.4)Origin IGP, localpref 100, valid, internal, best, group-bestReceived Path ID 0, Local Path ID 1, version 259Originator: 6.1.1.4, Cluster list: 6.1.1.100Link-state: MSD: Type 1 Value 10, Local TE Router-ID:

6.1.1.1 Remote TE Router-ID: 6.1.1.2, admin-group: 0x00000000max-link-bw (kbits/sec): 1000000, max-reserv-link-bw (kbits/sec): 0max-unreserv-link-bw (kbits/sec): 0 0 0 0 0 0 0 0, TE-default-metric: 10 metric: 10, ADJ-SID: 24002(30) Link Delay: 10 us Flags: 0x00, Min Delay: 10 us Max Delay: 10 us Flags: 0x00Delay Variation: 0 us

Task 10.1: Validate BGP LS Advertise TE Attributes



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R1

R2

R3

R4

R5

R6

R7

R8

R9

R101

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6

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3

10

SR-PCE1RR

On SR-PCE1pceaddress ipv4 6.1.1.101rest!!

RP/0/0/CPU0:SR-PCE1#show pce ipv4 prefix

PCE's prefix database: ----------------------Node 1TE router ID: 6.1.1.1Host name: R1ISIS system ID: 1921.5500.0001 level-1 ASN: 65001Advertised Prefixes:6.1.1.1

RP/0/0/CPU0:SR-PCE1#sh pce ipv4 path source 6.1.1.1 destination 6.1.1.10

Path:----:Hop0: 192.1.2.1Hop1: 192.2.4.2Hop2: 192.4.6.4Hop3: 192.6.8.6Hop4: 192.8.10.8

Task 11: Enable SR-PCE Functionality and Verify Operation



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segment-routingtraffic-engpccsource-address ipv4 6.1.1.1pce address ipv4 6.1.1.101 precedence 100

R1

segment-routingtraffic-engpccsource-address ipv4 6.1.1.10pce address ipv4 6.1.1.101 precedence 100

R10

RP/0/0/CPU0:SR-PCE1#sh pce ipv4 peer

PCE's peer database: --------------------Peer address: 6.1.1.1State: UpCapabilities: Stateful, Segment-Routing, Update, Instantiation

Peer address: 6.1.1.10State: UpCapabilities: Stateful, Segment-Routing, Update, Instantiation

SR-PCE1

RP/0/RP0/CPU0:R1#show segment-routing traffic-eng pcc ipv4 peer

PCC's peer database:--------------------

Peer address: 6.1.1.101, Precedence: 100, (best PCE)State upCapabilities: Stateful, Update, Segment-Routing, Instantiation

R1

Task 12: Configure R1 and R10 as PCC



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R1

R2

R3

R4

R5

R6

R7

R8

R9

R10

• On R1 and R10: Configure Route Policy to set color 2 for Matching Traffic

• Associate the color extended community with routes in VPNv4.

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9

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10

6.1.1.10

On R1*

router bgp 65001

neighbor 6.1.1.4address-family vpnv4 unicastroute-policy SET_COLOR_2 in


On R1 and R10extcommunity-set opaque COLOR_22

end-set

route-policy SET_COLOR_2set extcommunity color COLOR_2

end-policy

6.1.1.1

R1 and R10 R1

* Route can also be colored directly on VRF service configuration for better control/scalability

On R10*

router bgp 65001



R10

Task 13: Configure Slice Color (BGP Ext Community)


R1

R2

R3

R4

R5

R6

R7

R8

R9

R101

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10

6.1.1.10

RP/0/0/CPU0:R1#sh bgp vrf C-Blue 2.0.0.0

6.1.1.10 (metric 20) from 6.1.1.4 (6.1.1.10)

Received Label 24004

Extended community: Color:2 RT:65000:1

6.1.1.10 (metric 20) from 6.1.1.5 (6.1.1.10)Received Label 24004


6.1.1.1

RP/0/0/CPU0:R10#sh bgp vrf C-Blue 1.0.0.0

6.1.1.1 (metric 20) from 6.1.1.6 (6.1.1.1)

Received Label 24000


6.1.1.10 (metric 20) from 6.1.1.5 (6.1.1.10)Received Label 24004


R1 R10


R1 Configuration

segment-routingtraffic-engon-demand color 2dynamicpcep

!metrictype igp

R10 Configuration

segment-routingtraffic-engon-demand color 2dynamicpcep

!metrictype igp

R10R1

Task 14: Configure an “On-Demand” SRTE Policy

RP/0/0/CPU0:R1#sh segment-routing traffic-eng policySR-TE policy database---------------------Name: bgp_AP_5 (Color: 2, End-point: 6.1.1.10)

Status:Admin: up Operational: up

Candidate-paths:Preference 100:

Path Metrics:Margin Absolute: 0Margin Relative: 0%Maximum SID Depth: 10

Dynamic (pce 6.1.1.101) (active)Metric Type: IGP, Path Accumulated Metric: 50

16004 [Prefix-SID, 6.1.1.4]16006 [Prefix-SID, 6.1.1.6]16010 [Prefix-SID, 6.1.1.10]

Attributes:Binding SID: 24012

Allocation mode: dynamicState: ProgrammedPolicy selected: yes

Forward Class: 0Steering BGP disabled: noIPv6 caps enable: yesDistinguisher: 0

Auto-policy info:Creator: BGP

RP/0/0/CPU0:R10#sh segment-routing traffic-eng policySR-TE policy database---------------------Name: bgp_AP_3 (Color: 2, End-point: 6.1.1.1)

Status:Admin: up Operational: up

Candidate-paths:Preference 100:

Path Metrics:Margin Absolute: 0Margin Relative: 0%Maximum SID Depth: 10

Dynamic (pce 6.1.1.101) (active)Metric Type: IGP, Path Accumulated Metric: 50

16006 [Prefix-SID, 6.1.1.6]16004 [Prefix-SID, 6.1.1.4]16001 [Prefix-SID, 6.1.1.1]

Attributes:Binding SID: 24010

Allocation mode: dynamicState: ProgrammedPolicy selected: yes

Forward Class: 0Steering BGP disabled: noIPv6 caps enable: yesDistinguisher: 0

Auto-policy info:Creator: BGP

R10R1


R1

R2

R3

R4

R5

R6

R7

R8

R9

R10Core

ISIS L2Access

ISIS L1Access

ISIS L1

• Ping between R1 and R10, for MPLS as well as for L3VPN to check connectivity through On-Demand Next Hop

On Demand Next hop based reachability verification through ping



R1 ßà R10 MPLS and L3VPN Service Verification



RP/0/0/CPU0:R1#trace vrf C-Blue 2.0.0.6Type escape sequence to abort.Tracing the route to 2.0.0.61 192.1.2.2 [MPLS: Labels 16004/16006/16010/24000 Exp 0]2 192.2.4.4 [MPLS: Labels 16006/16010/24000 Exp 0]3 192.4.6.6 [MPLS: Labels 16010/24000 Exp 0]4 192.6.8.8 [MPLS: Labels 16010/24000 Exp 0] 5 192.8.10.10 59 msec * 39 msec

RP/0/0/CPU0:R10# trace vrf C-Blue 1.0.0.6Type escape sequence to abort.Tracing the route to 1.0.0.6

1 192.8.10.8 [MPLS: Labels 16006/16004/16001/24000 Exp 0]2 192.6.8.6 [MPLS: Labels 16004/16001/24000 Exp 0]3 192.4.6.4 [MPLS: Labels 16001/24000 Exp 0]4 192.2.4.2 [MPLS: Labels 16001/24000 Exp 0] 5 192.1.2.1 39 msec * 49 msec

SR SRTE PCE Hands On - LACNIC...Segment Routing Configuration Example –OSPF 27 router ospf1...

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