The Network Times

Book Table of Contents

Chapter 1: Underlay Network – OSPF Operation 1

Introduction 1

OSPF 2

Link-State Database (LSDB) optimization 3

Shortest-Path First (SPF)/Dijkstra Algorithm 8

SPF Run – Phase I: Building a Shortest-Path Tree 9

First iteration round 10

Second iteration round 11

Third iteration round 12

Fourth iteration round 13

Fifth iteration round 14

Sixth iteration round 15

Seventh iteration round 16

SPF Run – Phase II: Adding Leafs to Shortest-Path Tree 17

References: 19

Chapter 2: Underlay Network – Comparison of OSPF and IS-IS 20

Scenario-1: Interface loopback 50 down on Leaf-101 (IS-IS) 22

Scenario-2: Interface loopback 50 down on Leaf-101 (OSPF) 24

Scenario-3: OSPF Incremental SPF – L55 Down on Leaf-101 (Stub) 26

Scenario-4: OSPF Incremental SPF – Interface g0/3 Down on Spine-12 (transit link

does not participate in SPT) 27

Scenario-5: IS-IS SPF – Interface g0/3 Down on Spine-12 (Full SPF computation)

28

Scenario-6: IS-IS Incremental SPF – Interface g0/3 Down on Spine-12 29

(transit link does not participate in SPT) 29

Conclusion 30

Chapter 3: Underlay Network: iBGP in Underlay Network 32

Next-Hop-Self consideration 36

Case-1: Next-hop-self is changed by RR Spine-11. 36

Case-2: RR Spine-11 does not change Next-hop-self. 37

Chapter 4: Underlay Network: Two-AS eBGP 42

Underlay Network Control Plane eBGP 42

Overlay Network Control Plane: eBGP 46

References: 58

Chapter 5: eBGP as an Underlay Network Routing Protocol: Multi-AS eBGP 59

Underlay Network Control Plane: IPv4 eBGP peering 59

Overlay Network Control Plane: L2VPN EVPN eBGP peering 61

References: 69

Chapter 6: Layer 2 Multi-Destination Traffic - Anycast-RP with PIM. 70

Step 1: Configuring Anycast-RP cluster 71

Step 2: Assign unique Cluster Member IP and define members 71

Step 3: Assign unique Cluster Member IP and define members 72

Configuring NVE interface 74

Anycast-PIM Control Plane Operation 75

Phase 1: PIM Join 75

Phase 2: PIM Registration 76

Phase 3: PIM Registration-Stop 78

Phase 4: Anycast-RP peer notification 78

Data Plane operation 82

ARP Request 82

ARP Reply 83

References: 85

Chapter 7: Layer 2 Multi-destination traffic - PIM BiDir. 86

Configuration 86

Control Plane Operation 87

References 90

Chapter 8: BGP EVPN VXLAN Configuration and building blocks. 91

BGP EVPN VXLAN Building Blocks for Intra-VNI switching 91

Underlay Network: OSPF configuration 92

Overlay Network: BGP L2VPN EVPN configuration 93

Overlay Network: NVE Peering 93

Overlay Network: Host Mobility Manager 94

Overlay Network: Anycast Gateway (AGW) 94

Overlay Network: VLAN based service 95

Overlay Network: TCAM modification 95

Intra-VNI service (L2VNI) in VXLAN Fabric 96

Tenant based Inter-VNI Routing (L3VNI) in VXLAN Fabric 100

References 103

Chapter 9: BGP EVPN VXLAN Control and Data Plane Operation. 104

MAC address learning process 105

Phase 1: MAC Address-Table update 105

Phase 2: L2RIB Update 106 

Phase 3: BGP MAC Route Export on Local VTEP 107

Phase 4: BGP AFI L2EVPN MAC Route Import on Remote VTEP 110

Phase 5: MAC VRF on Remote VTEP 112

Phase 6: MAC Address Table on Remote VTEP 113

L2VNI: Intra-VNI Data Plane 113

ARP Request 114

ARP Reply 116

ICMP Request 118

ICMP Reply 120

Summary 121

MAC-IP address learning process 122

Phase 1: ARP Table on Local VTEP 123

Phase 2-3: MAC-IP on Local VTEP 123

Phase 4: BGP Route Export on Local VTEP 125

Phase 5: BGP Route Import on Remote VTEP 126

Phase 6: IP VRF on Remote VTEP 129

ARP-Suppression 130

Host route Advertisement: Inter-VNI routing (L3VNI) 132

Phase 1. Host Route in Local Routing Information Base (RIB) 133

Phase 2. Host Route BGP Process on Local VTEP 133

Phase 3. Host Route BGP Process on Remote VTEP 134

Phase 4. Installing Host Route into RIB of Remote VTEP 135

Data Plane operation 137

Phase 1. Switching in VNI30000 on VTEP-102 137

Phase 2. Routing from VNI30000 to VNI 10077 on VTEP-102 138

Phase 3. Routing from VNI10077 to VNI 10000 on VTEP-101 138

Summary 139

Prefix Advertisement 139

Phase 1: vmBeef start pinging to vmBebe 140

Phase 2: Local VTEP Leaf-101: ARP process 141

Phase 3: Remote VTEP Leaf-102: ARP process - Request 142

Phase 4: vmBebe: ARP process - Reply 143

Phase 5: remote VTEP switch Leaf-102: BGP Update 144

Phase 6: Local VTEP switch Leaf-102: BGP Update 144

Data Plane testing 148

Phase 1: vmBeef start pinging to vmBebe 149

Phase 2: Local VTEP Leaf-101: Routing 149

Phase 3-4: Remote VTEP Leaf-102: ARP request 150

Phase 5: vmBebe: ARP Reply 151

Phase 6: Remote VTEP Leaf-102: ICMP Request forwarding 152

Phase 7: vmBebe: ICMP reply 152

Phase 8-9: Remote VTEP Leaf-102: Routing decision and ICMP reply 152

Phase 10-11: Local VTEP Leaf-101: Routing decision and ICMP reply 153

Summary 156

References 157

Chapter 10: VXLAN fabric External Connections 158

eBGP Configuration between Border Leaf-102 and Ext-Ro01 158

Starting point 160

Chapter 11: Multihoming with vPC 190

Virtual Port Channel Configuration 190

Some other consideration for vPC: 197

VTEP redundancy with vPC 198

Advertising Primary IP address 204

References: 210

Chapter 12: Multihoming - vPC and Graceful Insertion and Removal (GIR) operation

211

Loopback addressing 211

Graceful Insertion and Removal (GIR) 212

Verifications. 213

Example-2 summary: BGP EVPN peering and NVE1 using the same Loopback

interface. 218

Conclusion 219

References: 220

Chapter 13: Using vPC Peer Link as an Underlay Backup Path 221

Configuration 222

Verification 223

References: 227

Chapter 14: VXLAN Fabric Firewall Implementation 228

Protected segment 229

Non-Protected segment 230

Connectivity Testing 238

References: 240

Chapter 15: EVPN ESI Multihoming 241

Introduction 241

Ethernet Segment Identifier (ESI) and Port-Channel 242

Designated Forwarder (DF) 243

Designated Forwarder 246

References: 248

Chapter 16: EVPN ESI Multihoming - Fast Convergence and Load Balancing 249

Ethernet A-D per ES route - Fast Convergence in the all-Active mode 249

Fast Convergence 254

Load Balancing (Aliasing) 257

Summary 258

References: 259

Chapter 17: EVPN ESI Multihoming - Data Flows and link failures 260

Introduction 260

Intra-VNI (L2VNI): Unicast Traffic 262

Scenario 1: Link E1/2 down on Leaf-102 262

Scenario 2: Core link down on Leaf-102. 265

Intra-VNI (L2VNI): Broadcast, Unknown Unicast and Multicast (BUM) traffic 266

Scenario 1: Traffic flow from Designated Forwarder 266

Scenario 2: Traffic flow from non-Designated Forwarder 267

CHAPTER 18: VXLAN EVPN Multi-Site 269

Shared EVPN domain limitations 269

EVPN Multi-Site Architecture Introduction 270

Intra-Site EVPN Domain (Fabric) 271

Intra-Site NVE peering and VXLAN tunnels 272

Summary 278

Shared Common EVPN Domain Connections 278

Border Gateway setup 279

Multi-Destination traffic forwarding 287

Designated Forwarder 287

Ingress-Replication 293

Fabric Link Failure 299

Normal State 300

Fabric-Link Failure 302

Fabric-Link Recovery 304

DCI-Link Failure 307

Normal State 308

DCI Link Failure 309

DCI Link Recovery 310

References 312

Chapter 19: Tenant Routed Multicast in VXLAN Fabric 313

Underlay Multicast Routing 315

PIM neighbor establishment process 315

Shared Multicast Tree for Intra-VN 316

Joining to Intra-VN Shared Tree 316

Joining to Intra-VN Source-Specific Tree 318

Tenant Routed Multicast (TRM) Configuration 325

Define Anycast-RP 325

Enable TRM on leaf switches 325

Define the tenant-based Multicast group for Multicast traffic. 326

Prevent PIM neighbor establishment within a specific VLAN 326

BGP afi IPv4 MVPN peering (Leaf) 327

BGP afi IPv4 MVPN peering (Spine) 327

Tenant Routed Multicast (TRM) operation 328

Shared/Source-Specific tree for Inter-VN 328

Verification 330

TRM Control Plane operation. 332

IGMP membership report 332

MVPN Source-Active Auto-Discovery 333

Data Plane Operation 340

Ingress leaf operation 340

Spine operation 341

Egress leaf operation 341

Summary 342

References 343