HP 5920 & 5900 Switch Series

Transcription

1 HP 5920 & 5900 Switch Series Layer 3 IP Routing Configuration Guide Part number: a Software version: Release 23xx Document version: 6W

2 Legal and notice information Copyright 2015 Hewlett-Packard Development Company, L.P. No part of this documentation may be reproduced or transmitted in any form or by any means without prior written consent of Hewlett-Packard Development Company, L.P. The information contained herein is subject to change without notice. HEWLETT-PACKARD COMPANY MAKES NO WARRANTY OF ANY KIND WITH REGARD TO THIS MATERIAL, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. Hewlett-Packard shall not be liable for errors contained herein or for incidental or consequential damages in connection with the furnishing, performance, or use of this material. The only warranties for HP products and services are set forth in the express warranty statements accompanying such products and services. Nothing herein should be construed as constituting an additional warranty. HP shall not be liable for technical or editorial errors or omissions contained herein.

3 Contents Configuring basic IP routing 1 Routing table 1 Dynamic routing protocols 2 Route preference 2 Load sharing 3 Route backup 3 Route recursion 3 Route redistribution 4 Extension attribute redistribution 4 Configuring the maximum lifetime for routes and labels in the RIB 4 Configuring the maximum lifetime for routes in the FIB 5 Configuring the maximum number of ECMP routes 5 Enabling the enhanced ECMP mode 6 Displaying and maintaining a routing table 6 Configuring static routing 8 Configuring a static route 8 Configuring BFD for static routes 9 Bidirectional control mode 9 Single-hop echo mode 10 Configuring static route FRR 11 Configuration guidelines 11 Configuration procedure 11 Displaying and maintaining static routes 12 Static route configuration examples 12 Basic static route configuration example 12 BFD for static routes configuration example (direct next hop) 14 BFD for static routes configuration example (indirect next hop) 17 Static route FRR configuration example 19 Configuring a default route 22 Configuring RIP 23 Overview 23 RIP route entries 23 Routing loop prevention 23 RIP operation 23 RIP versions 24 Protocols and standards 24 RIP configuration task list 25 Configuring basic RIP 25 Enabling RIP 25 Controlling RIP reception and advertisement on interfaces 26 Configuring a RIP version 27 Configuring RIP route control 27 Configuring an additional routing metric 28 Configuring RIPv2 route summarization 28 Disabling host route reception 29 Advertising a default route 29 Configuring received/redistributed route filtering 30 i

4 Configuring a preference for RIP 30 Configuring RIP route redistribution 31 Tuning and optimizing RIP networks 31 Configuration prerequisites 31 Configuring RIP timers 31 Configuring split horizon and poison reverse 32 Configuring the maximum number of ECMP routes 33 Enabling zero field check on incoming RIPv1 messages 33 Enabling source IP address check on incoming RIP updates 34 Configuring RIPv2 message authentication 34 Specifying a RIP neighbor 34 Configuring RIP network management 35 Configuring the RIP packet sending rate 35 Setting the maximum length of RIP packets 36 Configuring RIP GR 36 Configuring BFD for RIP 37 Configuring single-hop echo detection (for a directly connected RIP neighbor) 37 Configuring single-hop echo detection (for a specific destination) 37 Configuring bidirectional control detection 38 Configuring RIP FRR 38 Displaying and maintaining RIP 39 RIP configuration examples 40 Configuring basic RIP 40 Configuring RIP route redistribution 43 Configuring an additional metric for a RIP interface 45 Configuring RIP to advertise a summary route 46 Configuring BFD for RIP (single-hop echo detection for a directly connected neighbor) 49 Configuring BFD for RIP (single hop echo detection for a specific destination) 52 Configuring BFD for RIP (bidirectional detection in BFD control packet mode) 54 Configuring RIP FRR 58 Configuring OSPF 60 Overview 60 OSPF packets 60 LSA types 61 OSPF areas 61 Router types 63 Route types 64 Route calculation 65 OSPF network types 65 DR and BDR 65 Protocols and standards 66 OSPF configuration task list 67 Enabling OSPF 68 Configuration prerequisites 68 Configuration guidelines 68 Enabling OSPF on a network 69 Enabling OSPF on an interface 70 Configuring OSPF areas 70 Configuring a stub area 70 Configuring an NSSA area 71 Configuring a virtual link 71 Configuring OSPF network types 72 Configuration prerequisites 72 Configuring the broadcast network type for an interface 73 ii

5 Configuring the NBMA network type for an interface 73 Configuring the P2MP network type for an interface 74 Configuring the P2P network type for an interface 74 Configuring OSPF route control 75 Configuration prerequisites 75 Configuring OSPF route summarization 75 Configuring received OSPF route filtering 77 Configuring Type-3 LSA filtering 77 Configuring an OSPF cost for an interface 77 Configuring the maximum number of ECMP routes 78 Configuring OSPF preference 79 Configuring OSPF route redistribution 79 Advertising a host route 80 Tuning and optimizing OSPF networks 81 Configuration prerequisites 81 Configuring OSPF timers 81 Specifying LSA transmission delay 82 Specifying SPF calculation interval 82 Specifying the LSA arrival interval 83 Specifying the LSA generation interval 83 Disabling interfaces from receiving and sending OSPF packets 84 Configuring stub routers 84 Configuring OSPF authentication 85 Adding the interface MTU into DD packets 86 Configuring a DSCP value for OSPF packets 86 Configuring the maximum number of external LSAs in LSDB 86 Configuring OSPF exit overflow interval 87 Enabling compatibility with RFC Logging neighbor state changes 88 Configuring OSPF network management 88 Configuring the LSU transmit rate 89 Enabling OSPF ISPF 89 Configuring prefix suppression 89 Configuring prefix prioritization 90 Configuring OSPF PIC 91 Configuring OSPF GR 91 Configuring the OSPF GR restarter 91 Configuring OSPF GR helper 92 Triggering OSPF GR 93 Configuring OSPF NSR 93 Configuring BFD for OSPF 94 Configuring bidirectional control detection 94 Configuring single-hop echo detection 94 Configuring OSPF FRR 95 Configuration prerequisites 95 Configuration guidelines 95 Configuring OSPF FRR to calculate a backup next hop using the LFA algorithm 95 Configuring OSPF FRR to specify a backup next hop using a routing policy 96 Displaying and maintaining OSPF 96 OSPF configuration examples 97 Basic OSPF configuration example 98 OSPF route redistribution configuration example 100 OSPF summary route advertisement configuration example 102 OSPF stub area configuration example 105 iii

6 OSPF NSSA area configuration example 107 OSPF DR election configuration example 109 OSPF virtual link configuration example 113 OSPF GR configuration example 115 OSPF NSR configuration example 118 BFD for OSPF configuration example 120 OSPF FRR configuration example 123 Troubleshooting OSPF configuration 125 No OSPF neighbor relationship established 125 Incorrect routing information 125 Configuring IS-IS 127 Overview 127 Terminology 127 IS-IS address format 127 NET 128 IS-IS area 129 IS-IS network types 131 IS-IS PDUs 132 Protocols and standards 133 IS-IS configuration task list 134 Configuring basic IS-IS 135 Configuration prerequisites 135 Enabling IS-IS 135 Configuring the IS level and circuit level 135 Configuring P2P network type for an interface 136 Configuring IS-IS route control 136 Configuration prerequisites 136 Configuring IS-IS link cost 137 Specifying a preference for IS-IS 138 Configuring the maximum number of ECMP routes 138 Configuring IS-IS route summarization 139 Advertising a default route 139 Configuring IS-IS route redistribution 140 Configuring IS-IS route filtering 140 Configuring IS-IS route leaking 141 Tuning and optimizing IS-IS networks 142 Configuration prerequisites 142 Specifying the interval for sending IS-IS hello packets 142 Specifying the IS-IS hello multiplier 142 Specifying the interval for sending IS-IS CSNP packets 143 Configuring a DIS priority for an interface 143 Disabling an interface from sending/receiving IS-IS packets 143 Enabling an interface to send small hello packets 144 Configuring LSP parameters 144 Controlling SPF calculation interval 147 Configuring convergence priorities for specific routes 147 Setting the LSDB overload bit 147 Configuring system ID to host name mappings 148 Enabling the logging of neighbor state changes 149 Enabling IS-IS ISPF 149 Configuring IS-IS network management 150 Enhancing IS-IS network security 151 Configuration prerequisites 151 Configuring neighbor relationship authentication 151 iv

7 Configuring area authentication 151 Configuring routing domain authentication 152 Configuring IS-IS GR 152 Configuring IS-IS NSR 153 Configuring BFD for IS-IS 154 Configuring IS-IS FRR 154 Configuration prerequisites 155 Configuration guidelines 155 Configuring IS-IS FRR to automatically calculate a backup next hop 155 Configuring IS-IS FRR using a routing policy 155 Displaying and maintaining IS-IS 156 IS-IS configuration examples 157 Basic IS-IS configuration example 157 DIS election configuration example 161 IS-IS route redistribution configuration example 165 IS-IS authentication configuration example 169 IS-IS GR configuration example 171 IS-IS NSR configuration example 172 BFD for IS-IS configuration example 176 IS-IS FRR configuration example 178 Configuring BGP 182 Overview 182 BGP speaker and BGP peer 182 BGP message types 182 BGP path attributes 183 BGP route selection 187 BGP route advertisement rules 187 BGP load balancing 187 Settlements for problems in large-scale BGP networks 189 MP-BGP 191 BGP configuration views 192 Protocols and standards 193 BGP configuration task list 194 Configuring basic BGP 196 Enabling BGP 196 Configuring a BGP peer 197 Configuring a BGP peer group 199 Specifying the source interface for TCP connections 206 Generating BGP routes 207 Injecting a local network 207 Redistributing IGP routes 208 Controlling route distribution and reception 209 Configuring BGP route summarization 209 Advertising optimal routes in the IP routing table 211 Advertising a default route to a peer or peer group 211 Limiting routes received from a peer or peer group 212 Configuring BGP route filtering policies 213 Configuring BGP route dampening 217 Controlling BGP path selection 218 Specifying a preferred value for routes received 218 Configuring preferences for BGP routes 219 Configuring the default local preference 220 Configuring the MED attribute 221 Configuring the NEXT_HOP attribute 225 v

8 Configuring the AS_PATH attribute 227 Tuning and optimizing BGP networks 232 Configuring the keepalive interval and hold time 232 Configuring the interval for sending updates for the same route 234 Enabling BGP to establish an EBGP session over multiple hops 234 Enabling immediate reestablishment of direct EBGP connections upon link failure 235 Enabling 4-byte AS number suppression 236 Enabling MD5 authentication for BGP peers 236 Configuring BGP load balancing 237 Configuring IPsec for IPv6 BGP 238 Disabling BGP to establish a session to a peer or peer group 239 Configuring BGP soft-reset 240 Protecting an EBGP peer when memory usage reaches level 2 threshold 244 Configuring a large-scale BGP network 245 Configuring BGP community 245 Configuring BGP route reflection 246 Configuring a BGP confederation 248 Configuring BGP GR 249 Enabling SNMP notifications for BGP 250 Enabling logging of session state changes 250 Configuring BFD for BGP 251 Configuring BGP FRR 251 Configuring 6PE 254 Configuring basic 6PE 255 Configuring optional 6PE capabilities 255 Displaying and maintaining BGP 257 IPv4 BGP configuration examples 259 Basic BGP configuration example 259 BGP and IGP route redistribution configuration example 263 BGP route summarization configuration example 266 BGP load balancing configuration example 269 BGP community configuration example 272 BGP route reflector configuration example 275 BGP confederation configuration example 278 BGP path selection configuration example 282 BGP GR configuration example 285 BFD for BGP configuration example 287 BGP FRR configuration example 290 IPv6 BGP configuration examples 294 IPv6 BGP basic configuration example 294 IPv6 BGP route reflector configuration example 297 6PE configuration example 300 BFD for IPv6 BGP configuration example 303 IPv6 BGP FRR configuration example 306 IPsec for IPv6 BGP packets configuration example 310 Troubleshooting BGP 314 Symptom 314 Analysis 314 Solution 315 Configuring PBR 316 Introduction to PBR 316 Policy 316 PBR and Track 317 PBR configuration task list 317 vi

9 Configuring a policy 318 Creating a node 318 Configuring match criteria for a node 318 Configuring actions for a node 318 Configuring PBR 319 Configuring local PBR 319 Configuring interface PBR 319 Displaying and maintaining PBR 319 PBR configuration examples 320 Packet type-based local PBR configuration example 320 Packet type-based interface PBR configuration example 321 Configuring IPv6 static routing 324 Configuring an IPv6 static route 324 Configuring BFD for IPv6 static routes 325 Bidirectional control mode 325 Single-hop echo mode 326 Displaying and maintaining IPv6 static routes 327 IPv6 static routing configuration examples 327 Basic IPv6 static route configuration example 327 BFD for IPv6 static routes configuration example (direct next hop) 329 BFD for IPv6 static routes configuration example (indirect next hop) 332 Configuring an IPv6 default route 335 Configuring RIPng 336 Overview 336 RIPng route entries 336 RIPng packets 336 Protocols and standards 337 RIPng configuration task list 337 Configuring basic RIPng 337 Configuring RIPng route control 338 Configuring an additional routing metric 338 Configuring RIPng route summarization 338 Advertising a default route 339 Configuring received/redistributed route filtering 339 Configuring a preference for RIPng 340 Configuring RIPng route redistribution 340 Tuning and optimizing the RIPng network 340 Configuring RIPng timers 340 Configuring split horizon and poison reverse 341 Configuring zero field check on RIPng packets 341 Configuring the maximum number of ECMP routes 342 Configuring RIPng GR 342 Applying an IPsec profile 343 Displaying and maintaining RIPng 343 RIPng configuration examples 344 Basic RIPng configuration example 344 RIPng route redistribution configuration examples 346 RIPng IPsec profile configuration examples 349 Configuring OSPFv3 352 Overview 352 OSPFv3 packets 352 OSPFv3 LSA types 352 vii

10 Protocols and standards 353 OSPFv3 configuration task list 353 Enabling OSPFv3 354 Configuring OSPFv3 area parameters 355 Configuration prerequisites 355 Configuring a stub area 355 Configuring an NSSA area 356 Configuring an OSPFv3 virtual link 356 Configuring OSPFv3 network types 357 Configuration prerequisites 357 Configuring the OSPFv3 network type for an interface 357 Configuring an NBMA or P2MP neighbor 357 Configuring OSPFv3 route control 358 Configuration prerequisites 358 Configuring OSPFv3 route summarization 358 Configuring OSPFv3 received route filtering 359 Configuring Inter-Area-Prefix LSA filtering 359 Configuring an OSPFv3 cost for an interface 359 Configuring the maximum number of OSPFv3 ECMP routes 360 Configuring a preference for OSPFv3 361 Configuring OSPFv3 route redistribution 361 Tuning and optimizing OSPFv3 networks 363 Configuration prerequisites 363 Configuring OSPFv3 timers 363 Specifying LSA transmission delay 363 Specifying SPF calculation interval 364 Specifying the LSA generation interval 364 Configuring a DR priority for an interface 365 Ignoring MTU check for DD packets 365 Disabling interfaces from receiving and sending OSPFv3 packets 365 Enabling the logging of neighbor state changes 366 Configuring OSPFv3 network management 366 Configuring the LSU transmit rate 367 Configuring stub routers 367 Configuring prefix suppression 368 Configuring OSPFv3 GR 369 Configuring GR restarter 369 Configuring GR helper 370 Triggering OSPFv3 GR 370 Configuring OSPFv3 NSR 370 Configuring BFD for OSPFv3 371 Applying an IPsec profile 372 Displaying and maintaining OSPFv3 373 OSPFv3 configuration examples 374 OSPFv3 stub area configuration example 374 OSPFv3 NSSA area configuration example 379 OSPFv3 DR election configuration example 381 OSPFv3 route redistribution configuration example 384 OSPFv3 route summarization configuration example 387 OSPFv3 GR configuration example 391 OSPFv3 NSR configuration example 392 BFD for OSPFv3 configuration example 393 OSPFv3 IPsec profile configuration example 396 viii

11 Configuring IPv6 IS-IS 400 Overview 400 Configuring basic IPv6 IS-IS 400 Configuring IPv6 IS-IS route control 401 Tuning and optimizing IPv6 IS-IS networks 402 Configuration prerequisites 402 Assigning a convergence priority to IPv6 IS-IS routes 402 Configuring BFD for IPv6 IS-IS 402 Displaying and maintaining IPv6 IS-IS 403 IPv6 IS-IS configuration examples 403 IPv6 IS-IS basic configuration example 403 BFD for IPv6 IS-IS configuration example 408 Configuring IPv6 PBR 411 Introduction to IPv6 PBR 411 Policy 411 PBR and Track 412 IPv6 PBR configuration task list 412 Configuring an IPv6 policy 413 Creating an IPv6 node 413 Configuring match criteria for an IPv6 node 413 Configuring actions for an IPv6 node 413 Configuring IPv6 PBR 414 Configuring IPv6 local PBR 414 Configuring IPv6 interface PBR 414 Displaying and maintaining IPv6 PBR 415 IPv6 PBR configuration examples 415 Packet type-based IPv6 local PBR configuration example 415 Packet type-based IPv6 interface PBR configuration example 416 Configuring routing policies 419 Overview 419 Filters 419 Routing policy 420 Configuring filters 420 Configuration prerequisites 420 Configuring an IP prefix list 420 Configuring an AS path list 421 Configuring a community list 421 Configuring an extended community list 422 Configuring a routing policy 422 Configuration prerequisites 422 Creating a routing policy 422 Configuring if-match clauses 423 Configuring apply clauses 424 Configuring the continue clause 425 Displaying and maintaining the routing policy 426 Routing policy configuration examples 426 Applying a routing policy to IPv4 route redistribution 426 Applying a routing policy to IPv6 route redistribution 429 Support and other resources 432 Contacting HP 432 Subscription service 432 Related information 432 Documents 432 ix

12 Websites 432 Conventions 433 Index 435 x

13 Configuring basic IP routing The term "interface" in the routing features collectively refers to Layer 3 interfaces, including VLAN interfaces and Layer 3 Ethernet interfaces. You can set an Ethernet port as a Layer 3 interface by using the port link-mode route command (see Layer 2 LAN Switching Configuration Guide). IP routing directs IP packet forwarding on routers based on a routing table. This chapter focuses on unicast routing protocols. For more information about multicast routing protocols, see IP Multicast Configuration Guide. Routing table A RIB contains the global routing information and related information, including route recursion, route redistribution, and route extension information. The router selects optimal routes from the routing table and puts them into the FIB table, and it uses the FIB table to forward packets. For more information about the FIB table, see Layer 3 IP Services Configuration Guide. Table 1 categorizes routes by different criteria. Table 1 Route categories Criterion Destination Whether the destination is directly connected Origin Categories Network route The destination is a network. The subnet mask is less than 32 bits. Host route The destination is a host. The subnet mask is 32 bits. Direct route The destination is directly connected. Indirect route The destination is indirectly connected. Direct route A direct route is discovered by the data link protocol on an interface, and is also called an "interface route." Static route A static route is manually configured by an administrator. Dynamic route A dynamic route is dynamically discovered by a routing protocol. To view brief information about a routing table, use the display ip routing-table command: <Sysname> display ip routing-table Destinations : 19 Routes : 19 Destination/Mask Proto Pre Cost NextHop Interface /32 Direct InLoop /24 Direct Vlan /32 Direct Vlan /32 Direct InLoop /32 Direct Vlan /24 Static Vlan /24 OSPF Vlan3... 1

14 A route entry includes the following key items: Destination IP address of the destination host or network. Mask Mask length of the IP address. Pre Preference of the route. Among routes to the same destination, the route with the highest preference is optimal. Cost If multiple routes to a destination have the same preference, the one with the smallest cost is the optimal route. NextHop Next hop. Interface Output interface. Dynamic routing protocols Static routes work well in small, stable networks. They are easy to configure and require fewer system resources. However, in networks where topology changes occur frequently, a typical practice is to configure a dynamic routing protocol. Compared with static routing, a dynamic routing protocol is complicated to configure, requires more router resources, and consumes more network resources. Dynamic routing protocols dynamically collect and report reachability information to adapt to topology changes. They are suitable for large networks. Dynamic routing protocols can be classified by different criteria, as shown in Table 2. Table 2 Categories of dynamic routing protocols Criterion Operation scope Routing algorithm Destination address type IP version Categories IGPs Work within an AS. Examples include RIP, OSPF, and IS-IS. EGPs Work between ASs. The most popular EGP is BGP. Distance-vector protocols Examples include RIP and BGP. BGP is also considered a path-vector protocol. Link-state protocols Examples include OSPF and IS-IS. Unicast routing protocols Examples include RIP, OSPF, BGP, and IS-IS. Multicast routing protocols Examples include PIM-SM and PIM-DM. IPv4 routing protocols Examples include RIP, OSPF, BGP, and IS-IS. IPv6 routing protocols Examples include RIPng, OSPFv3, IPv6 BGP, and IPv6 IS-IS. An AS refers to a group of routers that use the same routing policy and work under the same administration. Route preference Routing protocols, including static and direct routing, each by default have a preference. If they find multiple routes to the same destination, the router selects the route with the highest preference as the optimal route. The preference of a direct route is always 0 and cannot be changed. You can configure a preference for each static route and each dynamic routing protocol. The following table lists the route types and default preferences. The smaller the value, the higher the preference. 2

15 Table 3 Route types and default route preferences Route type Preference Direct route 0 Multicast static route 1 OSPF 10 IS-IS 15 Unicast static route 60 RIP 100 OSPF ASE 150 OSPF NSSA 150 IBGP 255 EBGP 255 Unknown (route from an untrusted source) 256 Load sharing A routing protocol might find multiple optimal equal-cost routes to the same destination. You can use these routes to implement equal-cost multi-path (ECMP) load sharing. Static routing, IPv6 static routing, RIP, RIPng, OSPF, OSPFv3, BGP, IPv6 BGP, IS-IS, and IPv6 IS-IS support ECMP load sharing. Route backup Route backup can improve network availability. Among multiple routes to the same destination, the route with the highest priority is the primary route and others are secondary routes. The router forwards matching packets through the primary route. When the primary route fails, the route with the highest preference among the secondary routes is selected to forward packets. When the primary route recovers, the router uses it to forward packets. Route recursion To use a route that has an indirectly connected next hop, a router must perform route recursion to find the output interface to reach the next hop. The RIB records and saves route recursion information, including brief information about related routes, recursive paths, and recursion depth. 3

16 Route redistribution Route redistribution enables routing protocols to learn routing information from each other. A dynamic routing protocol can redistribute routes from other routing protocols, including direct and static routing. For more information, see the respective chapters on those routing protocols in this configuration guide. The RIB records redistribution relationships of routing protocols. Extension attribute redistribution Extension attribute redistribution enables routing protocols to learn route extension attributes from each other, including BGP extended community attributes, OSPF area IDs, route types, and router IDs. The RIB records extended attributes of each routing protocol and redistribution relationships of different routing protocol extended attributes. Configuring the maximum lifetime for routes and labels in the RIB Perform this task to prevent routes of a certain protocol from being aged out due to slow protocol convergence resulting from a large number of route entries or long GR period. The configuration takes effect at the next protocol or RIB process switchover. To configure the maximum lifetime for routes and labels in the RIB (IPv4): 1. Enter system view. system-view 2. Enter RIB view. Rib 3. Create a RIB IPv4 address family and enter RIB IPv4 address family view. 4. Configure the maximum lifetime for IPv4 routes and labels in the RIB. address-family ipv4 protocol protocol lifetime seconds By default, no RIB IPv4 address family is created. By default, the maximum lifetime for routes and labels in the RIB is 480 seconds. To configure the maximum route lifetime for routes and labels in the RIB (IPv6): 1. Enter system view. system-view 2. Enter RIB view. Rib 3. Create a RIB IPv6 address family and enter RIB IPv6 address family view. 4. Configure the maximum lifetime for IPv6 routes and labels in the RIB. address-family ipv6 protocol protocol lifetime seconds By default, no RIB IPv6 address family is created. By default, the maximum lifetime for routes and labels in the RIB is 480 seconds. 4

17 Configuring the maximum lifetime for routes in the FIB When GR or NSR is disabled, FIB entries must be retained for some time after a protocol process switchover or RIB process switchover. When GR or NSR is enabled, FIB entries must be removed immediately after a protocol or RIB process switchover to avoid routing issues. Perform this task to meet such requirements. To configure the maximum lifetime for routes in the FIB (IPv4): 1. Enter system view. system-view 2. Enter RIB view. Rib 3. Create a RIB IPv4 address family and enter its view. 4. Configure the maximum lifetime for IPv4 routes in the FIB. address-family ipv4 fib lifetime seconds By default, no RIB IPv4 address family is created. By default, the maximum lifetime for routes in the FIB is 600 seconds. To configure the maximum lifetime for routes in the FIB (IPv6): 1. Enter system view. system-view 2. Enter RIB view. Rib 3. Create a RIB IPv6 address family and enter its view. 4. Configure the maximum lifetime for IPv6 routes in the FIB. address-family ipv6 fib lifetime seconds By default, no RIB IPv6 address family is created. By default, the maximum lifetime for routes in the FIB is 600 seconds. Configuring the maximum number of ECMP routes This configuration takes effect at next reboot. Make sure the reboot does not impact your network. To configure the maximum number of ECMP routes: 1. Enter system view. system-view 2. Configure the maximum number of ECMP routes. max-ecmp-num number By default, the maximum number of ECMP routes is 8. 5

18 Enabling the enhanced ECMP mode In the default ECMP mode, when one or multiple ECMP routes fail, the device reallocates all traffic to the remaining routes. The enhanced ECMP mode enables the device to reallocate only the traffic of the failed routes to the remaining routes, ensuring forwarding continuity. This configuration takes effect at next reboot. Make sure the reboot does not impact your network. To enable the enhanced ECMP mode: 1. Enter system view. system-view 2. Enable the enhanced ECMP mode. ecmp mode enhanced By default, the enhanced ECMP mode is disabled. Displaying and maintaining a routing table Execute display commands in any view and reset commands in user view. Task Display the ECMP mode. Display routing table information. Display information about routes permitted by an IPv4 basic ACL. Display information about routes to a specific destination address. Display information about routes to a range of destination addresses. Display information about routes permitted by an IP prefix list. Display information about routes installed by a protocol. Display IPv4 route statistics. Display the maximum number of ECMP routes. Display route attribute information in the RIB. Display RIB GR state information. Display next hop information in the RIB. Command display ecmp mode display ip routing-table [ vpn-instance vpn-instance-name ] [ verbose ] display ip routing-table [ vpn-instance vpn-instance-name ] acl acl-number [ verbose ] display ip routing-table [ vpn-instance vpn-instance-name ] ip-address [ mask mask-length ] [ longer-match ] [ verbose ] display ip routing-table [ vpn-instance vpn-instance-name ] ip-address1 to ip-address2 [ verbose ] display ip routing-table [ vpn-instance vpn-instance-name ] prefix-list prefix-list-name [ verbose ] display ip routing-table [ vpn-instance vpn-instance-name ] protocol protocol [ inactive verbose ] display ip routing-table [ vpn-instance vpn-instance-name ] statistics display max-ecmp-num display rib attribute [ attribute-id ] display rib graceful-restart display rib nib [ self-originated ] [ nib-id ] [ verbose ] display rib nib protocol protocol-name [ verbose ] 6

19 Task Display next hop information for direct routes. Clear IPv4 route statistics. Display IPv6 routing table information. Display information about routes to an IPv6 destination address. Display information about routes permitted by an IPv6 basic ACL. Display information about routes to a range of IPv6 destination addresses. Display information about routes permitted by an IPv6 prefix list. Display information about routes installed by an IPv6 protocol. Display IPv6 route statistics. Display route attribute information in the IPv6 RIB. Display IPv6 RIB GR state information. Display next hop information in the IPv6 RIB. Display next hop information for IPv6 direct routes. Clear IPv6 route statistics. Command display route-direct nib [ nib-id ] [ verbose ] reset ip routing-table statistics protocol [ vpn-instance vpn-instance-name ] { protocol all } display ipv6 routing-table [ vpn-instance vpn-instance-name ] [ verbose ] display ipv6 routing-table [ vpn-instance vpn-instance-name ] ipv6-address [ prefix-length ] [ longer-match ] [ verbose ] display ipv6 routing-table [ vpn-instance vpn-instance-name ] acl acl6-number [ verbose ] display ipv6 routing-table [ vpn-instance vpn-instance-name ] ipv6-address1 to ipv6-address2 [ verbose ] display ipv6 routing-table [ vpn-instance vpn-instance-name ] prefix-list prefix-list-name [ verbose ] display ipv6 routing-table [ vpn-instance vpn-instance-name ] protocol protocol [ inactive verbose ] display ipv6 routing-table [ vpn-instance vpn-instance-name ] statistics display ipv6 rib attribute [ attribute-id ] display ipv6 rib graceful-restart display ipv6 rib nib [ self-originated ] [ nib-id ] [ verbose ] display ipv6 rib nib protocol protocol-name [ verbose ] display ipv6 route-direct nib [ nib-id ] [ verbose ] reset ipv6 routing-table statistics protocol [ vpn-instance vpn-instance-name ] { protocol all } 7

20 Configuring static routing Static routes are manually configured. If a network's topology is simple, you only need to configure static routes for the network to work correctly. Static routes cannot adapt to network topology changes. If a fault or a topological change occurs in the network, the network administrator must modify the static routes manually. Configuring a static route Before you configure a static route, complete the following tasks: Configure the physical parameters for related interfaces. Configure the link-layer attributes for related interfaces. Configure the IP addresses for related interfaces. You can associate Track with a static route to monitor the reachability of the next hops. For more information about Track, see High Availability Configuration Guide. To configure a static route: 1. Enter system view. system-view 2. Configure a static route. 3. (Optional.) Configure the default preference for static routes. Method 1: ip route-static dest-address { mask-length mask } { interface-type interface-number [ next-hop-address ] next-hop-address [ track track-entry-number ] vpn-instance d-vpn-instance-name next-hop-address [ track track-entry-number ] } [ permanent ] [ preference preference-value ] [ tag tag-value ] [ description description-text ] Method 2: ip route-static vpn-instance s-vpn-instance-name dest-address { mask-length mask } { interface-type interface-number [ next-hop-address ] next-hop-address [ public ] [ track track-entry-number ] vpn-instance d-vpn-instance-name next-hop-address [ track track-entry-number ] } [ permanent ] [ preference preference-value ] [ tag tag-value ] [ description description-text ] ip route-static default-preference default-preference-value Use either method. By default, no static route is configured. The default setting is 60. 8

21 4. (Optional.) Delete all static routes, including the default route. delete [ vpn-instance vpn-instance-name ] static-routes all To delete one static route, use the undo ip route-static command. Configuring BFD for static routes IMPORTANT: Enabling BFD for a flapping route could worsen the situation. BFD provides a general-purpose, standard, medium-, and protocol-independent fast failure detection mechanism. It can uniformly and quickly detect the failures of the bidirectional forwarding paths between two routers for protocols, such as routing protocols and MPLS. For more information about BFD, see High Availability Configuration Guide. Bidirectional control mode To use BFD bidirectional control detection between two devices, enable BFD control mode for each device's static route destined to the peer. To configure a static route and enable BFD control mode, use one of the following methods: Specify an output interface and a direct next hop. Specify an indirect next hop and a specific BFD packet source address for the static route. To configure BFD control mode for a static route (direct next hop): 1. Enter system view. system-view 2. Configure BFD control mode for a static route. Method 1: ip route-static dest-address { mask-length mask } interface-type interface-number next-hop-address bfd control-packet [ preference preference-value ] [ tag tag-value ] [ description description-text ] Method 2: ip route-static vpn-instance s-vpn-instance-name dest-address { mask-length mask } interface-type interface-number next-hop-address bfd control-packet [ preference preference-value ] [ tag tag-value ] [ description description-text ] Use either method. By default, BFD control mode for a static route is not configured. To configure BFD control mode for a static route (indirect next hop): 1. Enter system view. system-view 9

22 2. Configure BFD control mode for a static route. Method 1: ip route-static dest-address { mask-length mask } { next-hop-address bfd control-packet bfd-source ip-address vpn-instance d-vpn-instance-name next-hop-address bfd control-packet bfd-source ip-address } [ preference preference-value ] [ tag tag-value ] [ description description-text ] Method 2: ip route-static vpn-instance s-vpn-instance-name dest-address { mask-length mask } { next-hop-address bfd control-packet bfd-source ip-address vpn-instance d-vpn-instance-name next-hop-address bfd control-packet bfd-source ip-address } [ preference preference-value ] [ tag tag-value ] [ description description-text ] Use either method. By default, BFD control mode for a static route is not configured. Single-hop echo mode With BFD echo mode enabled for a static route, the output interface sends BFD echo packets to the destination device, which loops the packets back to test the link reachability. IMPORTANT: Do not use BFD for a static route with the output interface in spoofing state. To configure BFD echo mode for a static route: 1. Enter system view. system-view 2. Configure the source address of echo packets. 3. Configure BFD echo mode for a static route. bfd echo-source-ip ip-address Method 1: ip route-static dest-address { mask-length mask } interface-type interface-number next-hop-address bfd echo-packet [ preference preference-value ] [ tag tag-value ] [ description description-text ] Method 2: ip route-static vpn-instance s-vpn-instance-name dest-address { mask-length mask } interface-type interface-number next-hop-address bfd echo-packet [ preference preference-value ] [ tag tag-value ] [ description description-text ] By default, the source address of echo packets is not configured. For more information about this command, see High Availability Command Reference. Use either method. By default, BFD echo mode for a static route is not configured. 10

23 Configuring static route FRR A link or router failure on a path can cause packet loss and even routing loop. Static route fast reroute (FRR) uses BFD to detect failures and enables fast rerouting to minimize the impact of link or node failures. Figure 1 Network diagram As shown in Figure 1, upon a link failure, packets are directed to the backup next hop to avoid traffic interruption. You can either specify a backup next hop for FRR or enable FRR to automatically select a backup next hop (which must be configured in advance). Configuration guidelines Do not use static route FRR and BFD (for a static route) at the same time. Static route does not take effect when the backup output interface is unavailable. Equal-cost routes do not support static route FRR. The backup output interface and next hop cannot be modified, and cannot be the same as the primary output interface and next hop. Static route FRR is available only when the state of primary link (with Layer 3 interfaces staying up) changes from bidirectional to unidirectional or down. Configuration procedure To configure static route FRR by specifying a backup next hop: 1. Enter system view. system-view 2. Configure the source address of BFD echo packets. bfd echo-source-ip ip-address By default, the source address of BFD echo packets is not configured. For more information about this command, see High Availability Command Reference. 11

24 3. Configure static route FRR. Method 1: ip route-static dest-address { mask-length mask } interface-type interface-number [ next-hop-address [ backup-interface interface-type interface-number [ backup-nexthop backup-nexthop-address ] ] ] [ permanent ] Method 2: ip route-static vpn-instance s-vpn-instance-name dest-address { mask-length mask } interface-type interface-number [ next-hop-address [ backup-interface interface-type interface-number [ backup-nexthop backup-nexthop-address ] ] ] [ permanent ] Use either method. By default, static route FRR is not configured. Displaying and maintaining static routes Execute display commands in any view. Task Command Display static route information. display ip routing-table protocol static [ inactive verbose ] Display static route next hop information. Display static routing table information. display route-static nib [ nib-id ] [ verbose ] display route-static routing-table [ vpn-instance vpn-instance-name ] [ ip-address { mask-length mask } ] Static route configuration examples Basic static route configuration example Network requirements As shown in Figure 2, configure static routes on the switches for interconnections between any two hosts. 12

25 Figure 2 Network diagram Configuration procedure 1. Configure IP addresses for interfaces. (Details not shown.) 2. Configure static routes: # Configure a default route on Switch A. <SwitchA> system-view [SwitchA] ip route-static # Configure two static routes on Switch B. <SwitchB> system-view [SwitchB] ip route-static [SwitchB] ip route-static # Configure a default route on Switch C. <SwitchC> system-view [SwitchC] ip route-static Configure the default gateways of Host A, Host B, and Host C as , , and (Details not shown.) Verifying the configuration # Display static routes on Switch A. [SwitchA] display ip routing-table protocol static Summary Count : 1 Static Routing table Status : <Active> Summary Count : 1 Destination/Mask Proto Pre Cost NextHop Interface /0 Static Vlan500 Static Routing table Status : <Inactive> Summary Count : 0 # Display static routes on Switch B. 13

26 [SwitchB] display ip routing-table protocol static Summary Count : 2 Static Routing table Status : <Active> Summary Count : 2 Destination/Mask Proto Pre Cost NextHop Interface /24 Static Vlan500 Static Routing table Status : <Inactive> Summary Count : 0 # Use the ping command on Host B to test the reachability of Host A (Windows XP runs on the two hosts). C:\Documents and Settings\Administrator>ping Pinging with 32 bytes of data: Reply from : bytes=32 time=1ms TTL=126 Reply from : bytes=32 time=1ms TTL=126 Reply from : bytes=32 time=1ms TTL=126 Reply from : bytes=32 time=1ms TTL=126 Ping statistics for : Packets: Sent = 4, Received = 4, Lost = 0 (0% loss), Approximate round trip times in milli-seconds: Minimum = 1ms, Maximum = 1ms, Average = 1ms # Use the tracert command on Host B to test the reachability of Host A. C:\Documents and Settings\Administrator>tracert Tracing route to over a maximum of 30 hops 1 <1 ms <1 ms <1 ms <1 ms <1 ms <1 ms ms <1 ms <1 ms Trace complete. BFD for static routes configuration example (direct next hop) Network requirements As shown in Figure 3: Configure a static route to subnet /24 on Switch A. Configure a static route to subnet /24 on Switch B. Enable BFD for both routes. Configure a static route to subnet /24 and a static route to subnet /24 on Switch C. 14

27 When the link between Switch A and Switch B through the Layer 2 switch fails, BFD can detect the failure immediately. Switch A then communicates with Switch B through Switch C. Figure 3 Network diagram Table 4 Interface and IP address assignment Device Interface IP address Switch A VLAN-interface /24 Switch A VLAN-interface /24 Switch B VLAN-interface /24 Switch B VLAN-interface /24 Switch C VLAN-interface /24 Switch C VLAN-interface /24 Configuration procedure 1. Configure IP addresses for the interfaces. (Details not shown.) 2. Configure static routes and BFD: # Configure static routes on Switch A and enable BFD control mode for the static route that traverses the Layer 2 switch. <SwitchA> system-view [SwitchA] interface vlan-interface 10 [SwitchA-vlan-interface10] bfd min-transmit-interval 500 [SwitchA-vlan-interface10] bfd min-receive-interval 500 [SwitchA-vlan-interface10] bfd detect-multiplier 9 [SwitchA-vlan-interface10] quit [SwitchA] ip route-static vlan-interface bfd control-packet [SwitchA] ip route-static vlan-interface preference 65 [SwitchA] quit # Configure static routes on Switch B and enable BFD control mode for the static route that traverses the Layer 2 switch. <SwitchB> system-view [SwitchB] interface vlan-interface 10 [SwitchB-vlan-interface10] bfd min-transmit-interval 500 [SwitchB-vlan-interface10] bfd min-receive-interval 500 [SwitchB-vlan-interface10] bfd detect-multiplier 9 [SwitchB-vlan-interface10] quit 15

28 [SwitchB] ip route-static vlan-interface bfd control-packet [SwitchB] ip route-static vlan-interface preference 65 [SwitchB] quit # Configure static routes on Switch C. <SwitchC> system-view [SwitchC] ip route-static [SwitchC] ip route-static Verifying the configuration # Display BFD sessions on Switch A. <SwitchA> display bfd session Total Session Num: 1 Up Session Num: 1 Init Mode: Active IPv4 Session Working Under Ctrl Mode: LD/RD SourceAddr DestAddr State Holdtime Interface 4/ Up 2000ms Vlan10 The output shows that the BFD session has been created. # Display the static routes on Switch A. <SwitchA> display ip routing-table protocol static Summary Count : 1 Static Routing table Status : <Active> Summary Count : 1 Destination/Mask Proto Pre Cost NextHop Interface /24 Static Vlan10 Static Routing table Status : <Inactive> Summary Count : 0 The output shows that Switch A communicates with Switch B through VLAN-interface 10. Then the link over VLAN-interface 10 fails. # Display static routes on Switch A. <SwitchA> display ip routing-table protocol static Summary Count : 1 Static Routing table Status : <Active> Summary Count : 1 Destination/Mask Proto Pre Cost NextHop Interface /24 Static Vlan11 Static Routing table Status : <Inactive> Summary Count : 0 16

29 The output shows that Switch A communicates with Switch B through VLAN-interface 11. BFD for static routes configuration example (indirect next hop) Network requirements As shown in Figure 4: Switch A has a route to interface Loopback 1 ( /32) on Switch B, with the output interface VLAN-interface 10. Switch B has a route to interface Loopback 1 ( /32) on Switch A, with the output interface VLAN-interface 12. Switch D has a route to /32, with the output interface VLAN-interface 10, and a route to /32, with the output interface VLAN-interface 12. Perform the following configuration tasks: Configure a static route to subnet /24 on Switch A. Configure a static route to subnet /24 on Switch B. Enable BFD for both routes. Configure a static route to subnet /24 and a static route to subnet /24 on both Switch C and Switch D. When the link between Switch A and Switch B through Switch D fails, BFD can detect the failure immediately. Switch A then communicate with Switch B through Switch C. Figure 4 Network diagram Table 5 Interface and IP address assignment Device Interface IP address Switch A VLAN-interface /24 Switch A VLAN-interface /24 Switch A Loopback /32 Switch B VLAN-interface /24 Switch B VLAN-interface /24 Switch B Loopback /32 Switch C VLAN-interface /24 17

30 Device Interface IP address Switch C VLAN-interface /24 Switch D VLAN-interface /24 Switch D VLAN-interface /24 Configuration procedure 1. Configure IP addresses for interfaces. (Details not shown.) 2. Configure static routes and BFD: # Configure static routes on Switch A and enable BFD control mode for the static route that traverses Switch D. <SwitchA> system-view [SwitchA] bfd multi-hop min-transmit-interval 500 [SwitchA] bfd multi-hop min-receive-interval 500 [SwitchA] bfd multi-hop detect-multiplier 9 [SwitchA] ip route-static bfd control-packet bfd-source [SwitchA] ip route-static vlan-interface preference 65 [SwitchA] quit # Configure static routes on Switch B and enable BFD control mode for the static route that traverses Switch D. <SwitchB> system-view [SwitchB] bfd multi-hop min-transmit-interval 500 [SwitchB] bfd multi-hop min-receive-interval 500 [SwitchB] bfd multi-hop detect-multiplier 9 [SwitchB] ip route-static bfd control-packet bfd-source [SwitchB] ip route-static vlan-interface preference 65 [SwitchB] quit # Configure static routes on Switch C. <SwitchC> system-view [SwitchC] ip route-static [SwitchC] ip route-static # Configure static routes on Switch D. <SwitchD> system-view [SwitchD] ip route-static [SwitchD] ip route-static Verifying the configuration # Display BFD sessions on Switch A. <SwitchA> display bfd session Total Session Num: 1 Up Session Num: 1 Init Mode: Active IPv4 Session Working Under Ctrl Mode: LD/RD SourceAddr DestAddr State Holdtime Interface 4/ Up 2000ms 18

31 The output shows that the BFD session has been created. # Display the static routes on Switch A. <SwitchA> display ip routing-table protocol static Summary Count : 1 Static Routing table Status : <Active> Summary Count : 1 Destination/Mask Proto Pre Cost NextHop Interface /24 Static Vlan10 Static Routing table Status : <Inactive> Summary Count : 0 The output shows that Switch A communicates with Switch B through VLAN-interface 10. Then the link over VLAN-interface 10 fails. # Display static routes on Switch A. <SwitchA> display ip routing-table protocol static Summary Count : 1 Static Routing table Status : <Active> Summary Count : 1 Destination/Mask Proto Pre Cost NextHop Interface /24 Static Vlan11 Static Routing table Status : <Inactive> Summary Count : 0 The output shows that Switch A communicates with Switch B through VLAN-interface 11. Static route FRR configuration example Network requirements As shown in Figure 5, configure static routes on Switch S, Switch A, and Switch D, and configure static route FRR. When Link A becomes unidirectional, traffic can be switched to Link B immediately. Figure 5 Network diagram 19