H3C BGP Configuration Examples

Transcription

1 H3C BGP Configuration Examples Copyright 2017 New H3C Technologies Co., Ltd. All rights reserved. No part of this manual may be reproduced or transmitted in any form or by any means without prior written consent of New H3C Technologies Co., Ltd. The information in this document is subject to change without notice.

2 Contents Introduction 1 Prerequisites 1 Example: Configuring basic BGP 1 Network configuration 1 Analysis 1 Software versions used 1 Restrictions and guidelines 1 Procedures 2 Verifying the configuration 5 Configuration files 6 Examples: Configuring BGP and IGP route redistribution 7 Network configuration 7 Analysis 8 Software versions used 8 Restrictions and guidelines 8 Procedures 8 Verifying the configuration 10 Configuration files 11 Related documentation 13 i

3 Introduction This document provides BGP configuration examples. Prerequisites The configuration examples in this document were created and verified in a lab environment, and all the devices were started with the factory default configuration. When you are working on a live network, make sure you understand the potential impact of every command on your network. This document assumes that you have basic knowledge of BGP. Example: Configuring basic BGP Network configuration As shown in Figure 1, all switches run BGP. Run EBGP between Switch A and Switch B, and run IBGP between Switch B and Switch C so that Switch C can access the network /24 connected to Switch A. Figure 1 Network diagram Vlan-int /24 Loop /32 AS Vlan-int /24 Switch A EBGP AS Vlan-int /24 Loop /32 Vlan-int /24 Switch B IBGP Vlan-int /24 Loop /32 Switch C Analysis To enable Switch B to communicate with Switch C through loopback interfaces, enable OSPF in AS By default, BGP does not advertise local networks. To enable Switch C to access the network /24 connected directly to Switch A, perform the following tasks: Add network /24 to the BGP routing table of Switch A. Add networks /24 and /24 to the BGP routing table of Switch B. Software versions used This configuration example was created and verified on S7500EXS-CMW710-R7536P05. Restrictions and guidelines When you configure basic BGP, follow these restrictions and guidelines: 1

4 Use loopback interfaces to establish IBGP connections to prevent route flapping caused by port state changes. Loopback interfaces are virtual interfaces. Use the peer connect-interface command to specify the loopback interface as the source interface for establishing BGP connections. The EBGP peers, Switch A and Switch B, are located in different ASs. Typically, their loopback interfaces are not reachable to each other, so the switches use directly connected interfaces to establish EBGP sessions. Procedures 1. Configure IP addresses for interfaces: Configure an IP address for VLAN-interface 100. <SwitchA> system-view [SwitchA] interface Vlan-interface 100 [SwitchA-Vlan-interface100] ip address Configure IP addresses for other interfaces in the same way that VLAN-interface 100 is configured. (Details not shown.) 2. Configure IBGP: Configure Switch B. <SwitchB> system-view [SwitchB] bgp [SwitchB-bgp-default] router-id [SwitchB-bgp-default] peer as-number [SwitchB-bgp-default] peer connect-interface Loopback 0 [SwitchB-bgp-default] address-family ipv4 unicast [SwitchB-bgp-default-ipv4] peer enable [SwitchB-bgp-default-ipv4] quit [SwitchB-bgp-default] quit [SwitchB] ospf 1 [SwitchB-ospf-1] area 0 [SwitchB-ospf-1-area ] network [SwitchB-ospf-1-area ] network [SwitchB-ospf-1-area ] quit [SwitchB-ospf-1] quit Configure Switch C. <SwitchC> system-view [SwitchC] bgp [SwitchC-bgp-default] router-id [SwitchC-bgp-default] peer as-number [SwitchC-bgp-default] peer connect-interface Loopback 0 [SwitchC-bgp-default] address-family ipv4 unicast [SwitchC-bgp-default-ipv4] peer enable [SwitchC-bgp-default-ipv4] quit [SwitchC-bgp-default] quit [SwitchC] ospf 1 [SwitchC-ospf-1] area 0 [SwitchC-ospf-1-area ] network [SwitchC-ospf-1-area ] network

5 [SwitchC-ospf-1-area ] quit [SwitchC-ospf-1] quit Display BGP peer information on Switch C. [SwitchC] display bgp peer ipv4 BGP local router ID : Local AS number : Total number of peers : 1 Peers in established state : 1 Peer AS MsgRcvd MsgSent OutQ PrefRcv Up/Down State :00:13 Established The output shows that Switch C has established an IBGP peer relationship with Switch B. 3. Configure EBGP: Configure Switch A. <SwitchA> system-view [SwitchA] bgp [SwitchA-bgp-default] router-id [SwitchA-bgp-default] peer as-number [SwitchA-bgp-default] address-family ipv4 unicast [SwitchA-bgp-default-ipv4] peer enable [SwitchA-bgp-default-ipv4] network [SwitchA-bgp-default-ipv4] quit [SwitchA-bgp-default] quit Configure Switch B. [SwitchB] bgp [SwitchB-bgp-default] peer as-number [SwitchB-bgp-default] address-family ipv4 unicast [SwitchB-bgp-default-ipv4] peer enable [SwitchB-bgp-default-ipv4] quit [SwitchB-bgp-default] quit Display BGP peer information on Switch B. [SwitchB] display bgp peer ipv4 BGP local router ID : Local AS number : Total number of peers : 2 Peers in established state : 2 Peer AS MsgRcvd MsgSent OutQ PrefRcv Up/Down State :02:49 Established :00:05 Established The output shows that Switch B has established an IBGP peer relationship with Switch C and an EBGP peer relationship with Switch A. Display the BGP routing table on Switch A. [SwitchA] display bgp routing-table ipv4 Total number of routes: 1 3

6 BGP local router ID is Status codes: * - valid, > - best, d - dampened, h - history, s - suppressed, S - stale, i - internal, e - external Origin: i - IGP, e - EGP,? - incomplete Network NextHop MED LocPrf PrefVal Path/Ogn * > / i Display the BGP routing table on Switch B. [SwitchB] display bgp routing-table ipv4 Total number of routes: 1 BGP local router ID is Status codes: * - valid, > - best, d - dampened, h - history, s - suppressed, S - stale, i - internal, e - external Origin: i - IGP, e - EGP,? - incomplete Network NextHop MED LocPrf PrefVal Path/Ogn * >e / i Display the BGP routing table on Switch C. [SwitchC] display bgp routing-table ipv4 Total number of routes: 1 BGP local router ID is Status codes: * - valid, > - best, d - dampened, h - history, s - suppressed, S - stale, i - internal, e - external Origin: i - IGP, e - EGP,? - incomplete Network NextHop MED LocPrf PrefVal Path/Ogn i / i The outputs show that Switch A has learned no route to AS 65009, and Switch C has learned network , but the next hop is unreachable. As a result, the route is invalid. 4. Configure BGP to redistribute direct routes on Switch B: Configure Switch B. [SwitchB] bgp [SwitchB-bgp-default] address-family ipv4 unicast [SwitchB-bgp-default-ipv4] network [SwitchB-bgp-default-ipv4] network [SwitchB-bgp-default-ipv4] quit [SwitchB-bgp-default] quit Display the BGP routing table on Switch A. [SwitchA] display bgp routing-table ipv4 4

7 Total number of routes: 3 BGP local router ID is Status codes: * - valid, > - best, d - dampened, h - history, s - suppressed, S - stale, i - internal, e - external Origin: i - IGP, e - EGP,? - incomplete Network NextHop MED LocPrf PrefVal Path/Ogn * >e / ? * > / i * >e / i The output shows that route /24 has been added in Switch A's routing table. Display the BGP routing table on Switch C. [SwitchC] display bgp routing-table ipv4 Total number of routes: 3 BGP local router ID is Status codes: * - valid, > - best, d - dampened, h - history, s - suppressed, S - stale, i - internal, e - external Origin: i - IGP, e - EGP,? - incomplete Network NextHop MED LocPrf PrefVal Path/Ogn * >i / ? * >i / i * >i / i The output shows that the route becomes valid with the next hop as Switch A. Verifying the configuration Verify that Switch C can ping [SwitchC] ping Ping ( ): 56 data bytes, press CTRL_C to break 56 bytes from : icmp_seq=0 ttl=254 time= ms 56 bytes from : icmp_seq=1 ttl=254 time=4.000 ms 56 bytes from : icmp_seq=2 ttl=254 time=4.000 ms 56 bytes from : icmp_seq=3 ttl=254 time=3.000 ms 56 bytes from : icmp_seq=4 ttl=254 time=3.000 ms --- Ping statistics for packet(s) transmitted, 5 packet(s) received, 0.0% packet loss round-trip min/avg/max/std-dev = 3.000/4.800/10.000/2.638 ms 5

8 Configuration files Switch A: vlan 100 vlan 200 interface Loopback0 ip address interface Vlan-interface100 ip address interface Vlan-interface200 ip address bgp router-id peer as-number address-family ipv4 unicast network peer enable Switch B: vlan 200 vlan 300 interface Loopback0 ip address interface Vlan-interface200 ip address interface Vlan-interface300 ip address bgp router-id peer as-number peer as-number peer connect-interface Loopback0 address-family ipv4 unicast network

9 network peer enable peer enable ospf 1 area network network Switch C: vlan 300 interface Loopback0 ip address interface Vlan-interface300 ip address bgp router-id peer as-number peer connect-interface Loopback0 address-family ipv4 unicast peer enable ospf 1 area network network Examples: Configuring BGP and IGP route redistribution Network configuration As shown in Figure 2, all devices of company A belong to AS and all devices of company B belong to AS Run EBGP between Switch A and Switch B, and run OSPF between Switch B and Switch C to allow communication only between networks /24 and /24. 7

10 Figure 2 Network diagram Vlan-int /24 AS Loop /32 EBGP AS Loop /32 OSPF Loop /32 Vlan-int /24 Vlan-int /24 Vlan-int /24 Switch A Vlan-int /24 Switch B Vlan-int /24 Vlan-int /24 Switch C Vlan-int /24 Analysis To enable Switch A to obtain the route to /24, configure BGP to redistribute routes from OSPF on Switch B. To enable Switch C to obtain the route to /24, configure OSPF to redistribute routes from BGP on Switch B. Software versions used This configuration example was created and verified on S7500EXS-CMW710-R7536P05. Restrictions and guidelines The EBGP peers, Switch A and Switch B, are located in different ASs. Typically, their loopback interfaces are not reachable to each other, so the switches use directly connected interfaces to establish EBGP sessions. Procedures 1. Configure IP addresses for interfaces: Configure an IP address for VLAN-interface 100. <SwitchA> system-view [SwitchA] interface Vlan-interface 100 [SwitchA-Vlan-interface100] ip address Configure IP addresses for other interfaces in the same way that VLAN-interface 100 is configured. (Details not shown.) 2. Enable OSPF in AS 65009: Configure Switch B. <SwitchB> system-view [SwitchB] ospf 1 [SwitchB-ospf-1] area 0 [SwitchB-ospf-1-area ] network [SwitchB-ospf-1-area ] network [SwitchB-ospf-1-area ] quit [SwitchB-ospf-1] quit Configure Switch C. <SwitchC> system-view 8

11 [SwitchC] ospf 1 [SwitchC-ospf-1] area 0 [SwitchC-ospf-1-area ] network [SwitchC-ospf-1-area ] network [SwitchC-ospf-1-area ] quit [SwitchC-ospf-1] quit 3. Configure the EBGP connection and add network /24 to the BGP routing table of Switch A: Configure Switch A. <SwitchA> system-view [SwitchA] bgp [SwitchA-bgp-default] router-id [SwitchA-bgp-default] peer as-number [SwitchA-bgp-default] address-family ipv4 unicast [SwitchA-bgp-default-ipv4] peer enable [SwitchA-bgp-default-ipv4] network [SwitchA-bgp-default-ipv4] quit [SwitchA-bgp-default] quit Configure Switch B. [SwitchB] bgp [SwitchB-bgp-default] router-id [SwitchB-bgp-default] peer as-number [SwitchB-bgp-default] address-family ipv4 unicast [SwitchB-bgp-default-ipv4] peer enable 4. Configure BGP and IGP route redistribution: Configure route redistribution between BGP and OSPF on Switch B. [SwitchB-bgp-default-ipv4] import-route ospf 1 [SwitchB-bgp-default-ipv4] quit [SwitchB-bgp-default] quit [SwitchB] ospf 1 [SwitchB-ospf-1] import-route bgp [SwitchB-ospf-1] quit Display the BGP routing table on Switch A. [SwitchA] display bgp routing-table ipv4 Total number of routes: 3 BGP local router ID is Status codes: * - valid, > - best, d - dampened, h - history, s - suppressed, S - stale, i - internal, e - external Origin: i - IGP, e - EGP,? - incomplete Network NextHop MED LocPrf PrefVal Path/Ogn * > / i * >e / ? The output shows that Switch A has obtained the route to /24. Display the OSPF routing table on Switch C. 9

12 [SwitchC] display ospf routing OSPF Process 1 with Router ID Routing Tables Routing for Network Destination Cost Type NextHop AdvRouter Area /24 1 Transit /24 1 Stub /32 1 Stub Routing for ASEs Destination Cost Type Tag NextHop AdvRouter /24 1 Type Total Nets: 3 Intra Area: 2 Inter Area: 0 ASE: 1 NSSA: 0 The output shows that Switch C has obtained the route to /24. Verifying the configuration Verify that can ping [SwitchA] ping -a Ping ( ) from : 56 data bytes, press CTRL_C to break 56 bytes from : icmp_seq=0 ttl=254 time= ms 56 bytes from : icmp_seq=1 ttl=254 time= ms 56 bytes from : icmp_seq=2 ttl=254 time=2.000 ms 56 bytes from : icmp_seq=3 ttl=254 time=7.000 ms 56 bytes from : icmp_seq=4 ttl=254 time=9.000 ms --- Ping statistics for packet(s) transmitted, 5 packet(s) received, 0.0% packet loss round-trip min/avg/max/std-dev = 2.000/8.000/12.000/3.406 ms Verify that can ping [SwitchC] ping -a Ping ( ) from : 56 data bytes, press CTRL_C to break 56 bytes from : icmp_seq=0 ttl=254 time=9.000 ms 56 bytes from : icmp_seq=1 ttl=254 time=4.000 ms 56 bytes from : icmp_seq=2 ttl=254 time=3.000 ms 56 bytes from : icmp_seq=3 ttl=254 time=3.000 ms 56 bytes from : icmp_seq=4 ttl=254 time=3.000 ms --- Ping statistics for packet(s) transmitted, 5 packet(s) received, 0.0% packet loss round-trip min/avg/max/std-dev = 3.000/4.400/9.000/2.332 ms Verify that cannot ping or [SwitchA] ping a Ping ( ) from : 56 data bytes, press CTRL_C to break 10

13 --- Ping statistics for packet(s) transmitted, 0 packet(s) received, 100.0% packet loss [SwitchA] ping a Ping ( ) from : 56 data bytes, press CTRL_C to break --- Ping statistics for packet(s) transmitted, 0 packet(s) received, 100.0% packet loss Verify that cannot ping or [SwitchC] ping a Ping ( ) from : 56 data bytes, press CTRL_C to break --- Ping statistics for packet(s) transmitted, 0 packet(s) received, 100.0% packet loss [SwitchC] ping a Ping ( ) from : 56 data bytes, press CTRL_C to break --- Ping statistics for packet(s) transmitted, 0 packet(s) received, 100.0% packet loss Configuration files Switch A: vlan

14 vlan 200 vlan 600 interface Loopback0 ip address interface Vlan-interface100 ip address interface Vlan-interface200 ip address interface Vlan-interface600 ip address bgp router-id peer as-number address-family ipv4 unicast network peer enable Switch B: vlan 200 vlan 300 vlan 500 interface Loopback0 ip address interface Vlan-interface200 ip address interface Vlan-interface300 ip address bgp router-id peer as-number address-family ipv4 unicast import-route ospf 1 peer enable 12

15 ospf 1 import-route bgp area network network Switch C: vlan 300 vlan 400 interface Loopback0 ip address interface Vlan-interface300 ip address interface Vlan-interface400 ip address interface Vlan-interface500 ip address ospf 1 area network network Related documentation H3C S7500E-XS Switch Series Layer 3 IP Routing Command Reference-R7536P05 H3C S7500E-XS Switch Series Layer 3 IP Routing Configuration Guide-R7536P05 13