Configurar o BGP IPv6 Flowspec

Introduction

Este documento descreve como configurar o BGP (Border Gateway Protocol) IPv6 Flowspec em ASR1K.

Prerequisites

Requirements

A Cisco recomenda ter conhecimento deste tópico:

• Independente da plataforma

Componentes Utilizados

As informações neste documento são baseadas nestas versões de software e hardware:

• IOS-XE
• ASR1000
• ASR9K 
• ASR1K 
• BGP
• Flowspec
• IPv6

The information in this document was created from the devices in a specific lab environment. All of the devices used in this document started with a cleared (default) configuration. Se a rede estiver ativa, certifique-se de que você entenda o impacto potencial de qualquer comando.

Informações de Apoio

O Flowspec especifica os procedimentos para a distribuição de regras de especificação de fluxo via BGP e define o procedimento para codificar regras de especificação de fluxo como Informações de Alcançabilidade da Camada de Rede do Protocolo de Gateway de Borda (BGP NLRI - Network Layer Reachability Information) que podem ser usadas em qualquer aplicativo. Ele também define a aplicação para a finalidade da filtragem de pacotes a fim de atenuar ataques de negação de serviço (distribuídos).

Limitações

Estas são as limitações para a configuração:

• Uma combinação de famílias de endereços não é permitida nas regras de fluxograma.
• No cenário de correspondência múltipla, somente a primeira regra de fluxograma correspondente é aplicada.
• Um máximo de 3000 regras de fluxograma é suportado por sistema.

Configurar

Neste exemplo, configuramos ASR9K como controlador e ASR1K como um cliente PE, RR e Flowspec.

Essa é a configuração mínima necessária para que o Flowspec do IPv6 funcione.

On controller to push the policy to PE/client:
class-map type traffic match-all FLOWSPEC
 match destination-address ipv6 2001:db8::/32   <<<<< Match destination address/subnet.
 end-class-map
!
policy-map type pbr FS_P
 class type traffic FLOWSPEC                    <<<<< Apply class-map under policy-map.
  drop
 !
flowspec
 address-family ipv4
  service-policy type pbr FSP_V4
 !
 address-family ipv6
  service-policy type pbr FS_P                  <<<<< Apply policy-map inside Flowspec under AF.
 !

On PE/client is to enable IPv6 flowspec AF under BGP.
 address-family ipv6 flowspec                   <<<<< Under ipv6 flowspec AF, activate the neighbor.
  neighbor 10.192.202.5 activate
  neighbor 10.192.202.5 validation off

To apply the flowspec policy on interface, "local-install interface-all" command is must under flowspec.
flowspec
 local-install interface-all                    <<<<< Push the policy on interface.

• Com base na configuração do controlador, qualquer tráfego destinado a 2001:db8::/32 deve ser descartado de acordo com a política.
  
  
• Mantenha a validação desativada para o vizinho em ipv6 address-family para que ASR1K não verifique o próximo salto.
  
  
• Idealmente, se a política estiver em ação, o contador será visto no controlador, mas, caso você queira vê-lo em qualquer outro dispositivo, instale a política flowspec em todas as interfaces do usuário para as quais o comando local-install interface-all é necessário sob flowspec.

Desafios durante a solução de problemas

• Se a rede subjacente for IPv4 e o fluxograma de BGP for executado para IPv6, então há um problema de verificação de validação em cada salto e causa um problema para a política de Flowspec de IPv6. Portanto, mantenha a validação desligada para que o vizinho não faça a verificação de validação.
  
  
• Além de um controlador, você não pode ver a correspondência/contador de ação da política de fluxspec. Para verificar os contadores, interface local-install-all deve estar em Flowspec (sob AF). Esse comando envia a configuração da política de especificação de fluxo em todas as interfaces de um dispositivo para as famílias de endereços IPv4 e IPv6 e em interfaces dentro de uma instância de VRF.

Diagrama de Rede

+----------------+              +-----------------+            +------------------+             +-----------------+
|                |              |                 |            |                  |             |                 |
|   Controller   +--------------+     PE/RR1      +------------+      PE/RR2      +-------------+      End-PE     |
|     ASR9K      |              |     CRR01       |            |      CRR02       |             |      DCPR01     |
+----------------+              +-----------------+            +------------------+             +-----------------+

Configurações

Essa configuração é baseada no diagrama de rede, o mesmo da sua configuração.

Controller:
RP/0/RSP0/CPU0:Controller# show running-config
Mon Apr  8 16:33:36.578 UTC
Building configuration...
!! IOS XR Configuration 5.3.4
!! Last configuration change at Wed Apr  3 17:34:59 2019 by admin
!
hostname Controller
cdp
cdp advertise v1
!
class-map type traffic match-all FLOWSPEC
 match destination-address ipv6 2001:db8::/32
 end-class-map
!
class-map type traffic match-all V4_FLOWSPEC
 match source-address ipv4 102.102.102.102 255.255.255.255
 end-class-map
!
policy-map type pbr FS_P
 class type traffic FLOWSPEC
  drop
 !
 class type traffic class-default
 !
 end-policy-map
!
policy-map type pbr FSP_V4
 class type traffic V4_FLOWSPEC
  set dscp ef
 !
 class type traffic class-default
 !
 end-policy-map
!
interface Loopback0
 ipv4 address 10.192.202.5 255.255.255.255
!
interface Loopback100
 ipv4 address 102.102.102.102 255.255.255.255
 ipv6 address 2001:db8::1/32
!
interface TenGigE0/0/0/0
 ipv4 address 10.10.12.1 255.255.255.0
 ipv6 address 2001:10:10:12::1/64
!
route-policy ALL
  pass
end-policy
!
router static
 address-family ipv4 unicast
  203.202.143.33/32 TenGigE0/0/0/0
 !
 address-family ipv6 unicast
  2003::/64 2001:10:10:12::2
 !
!
router ospfv3 1
 area 0
  interface TenGigE0/0/0/0
   network point-to-point
  !
 !
!
router bgp 64696
 bgp router-id 10.192.202.5
 address-family ipv4 unicast
  network 102.102.102.102/32
 !
 address-family vpnv4 unicast
 !
 address-family ipv4 flowspec
 !
 address-family ipv6 flowspec
 !
 neighbor 203.202.143.33
  remote-as 7474
  ebgp-multihop 10
  update-source Loopback0
  address-family ipv4 unicast
   route-policy ALL in
   route-policy ALL out
  !
  address-family vpnv4 unicast
  !
  address-family ipv4 flowspec
   route-policy ALL in
   route-policy ALL out
  !
  address-family ipv6 flowspec
   route-policy ALL in
   route-policy ALL out
  !
 !
!
flowspec
 local-install interface-all
 address-family ipv4
  service-policy type pbr FSP_V4
 !
 address-family ipv6
  service-policy type pbr FS_P
 !
!
end

PE/RR1:
CRR01#show running-config
Building configuration...

!
ipv6 unicast-routing
mpls label protocol ldp
!
spanning-tree extend system-id
flowspec
 local-install interface-all
diagnostic bootup level minimal
!
interface Loopback0
 ip address 203.202.143.33 255.255.255.255
 ip ospf 1 area 0
!
interface Loopback1010
 no ip address
 ipv6 address 2001:DB8::10/32
!
interface TenGigabitEthernet0/0/0
 ip address 10.10.12.2 255.255.255.0
 ip ospf network point-to-point
 cdp enable
 ipv6 address 2001:10:10:12::2/64
!
interface TenGigabitEthernet0/0/3
 ip address 10.10.23.2 255.255.255.0
 ip ospf network point-to-point
 ip ospf 1 area 0
 cdp enable
 ipv6 address 2003::1/64
 mpls ip
!
router ospf 1
 mpls ldp autoconfig
!
router bgp 7474
 bgp router-id 203.202.143.33
 bgp log-neighbor-changes
 neighbor 10.192.202.5 remote-as 64696
 neighbor 10.192.202.5 ebgp-multihop 10
 neighbor 10.192.202.5 update-source Loopback0
 neighbor 2001:10:10:12::1 remote-as 64696
 neighbor 203.202.143.44 remote-as 7474
 neighbor 203.202.143.44 update-source Loopback0
 !
 address-family ipv4
  neighbor 10.192.202.5 activate
  no neighbor 2001:10:10:12::1 activate
  neighbor 203.202.143.44 activate
  neighbor 203.202.143.44 route-reflector-client
 exit-address-family
 !
 address-family ipv4 flowspec
  neighbor 10.192.202.5 activate
  neighbor 203.202.143.44 activate
  neighbor 203.202.143.44 send-community both
  neighbor 203.202.143.44 route-reflector-client
 exit-address-family
 !
 address-family ipv6
  neighbor 10.192.202.5 activate
  neighbor 203.202.143.44 activate
  neighbor 203.202.143.44 route-reflector-client
  neighbor 203.202.143.44 send-label
 exit-address-family
 !
 address-family ipv6 flowspec
  neighbor 10.192.202.5 activate
  neighbor 10.192.202.5 validation off
  neighbor 203.202.143.44 activate
  neighbor 203.202.143.44 send-community both
  neighbor 203.202.143.44 route-reflector-client
  neighbor 203.202.143.44 next-hop-self
 exit-address-family
!
ip route 10.192.202.5 255.255.255.255 10.10.12.1
!
!
ipv6 route 2001:DB8::1/128 2001:10:10:12::1
!
end

PE/RR2:
CRR02#show running-config
Building configuration...

Current configuration : 7227 bytes
!
! Last configuration change at 18:21:29 UTC Mon Apr 8 2019
!
hostname CRR02
!
boot-start-marker
boot system flash bootflash:asr1000rpx86-universalk9.16.10.01a.SPA.bin
boot-end-marker
!
ipv6 unicast-routing
multilink bundle-name authenticated
!
spanning-tree extend system-id
flowspec
diagnostic bootup level minimal
!
interface Loopback0
 ip address 203.202.143.44 255.255.255.255
 ip ospf 1 area 0
!
interface TenGigabitEthernet1/0/0
 ip address 10.10.23.3 255.255.255.0
 ip ospf network point-to-point
 ip ospf 1 area 0
 cdp enable
 ipv6 address 2003::2/64
 mpls ip
!
interface TenGigabitEthernet1/0/1
 ip address 10.10.34.3 255.255.255.0
 ip ospf network point-to-point
 ip ospf 1 area 0
 cdp enable
!
router ospf 1
 mpls ldp autoconfig
!
router bgp 7474
 bgp router-id 203.202.143.44
 bgp log-neighbor-changes
 neighbor 203.202.143.33 remote-as 7474
 neighbor 203.202.143.33 update-source Loopback0
 neighbor 203.202.143.45 remote-as 7474
 neighbor 203.202.143.45 update-source Loopback0
 !
 address-family ipv4
  neighbor 203.202.143.33 activate
  neighbor 203.202.143.45 activate
 exit-address-family
 !
 address-family ipv4 flowspec
  neighbor 203.202.143.33 activate
  neighbor 203.202.143.45 activate
  neighbor 203.202.143.45 send-community both
  neighbor 203.202.143.45 route-reflector-client
 exit-address-family
 !
 address-family ipv6
  neighbor 203.202.143.33 activate
  neighbor 203.202.143.33 send-label
 exit-address-family
 !
 address-family ipv6 flowspec
  neighbor 203.202.143.33 activate
  neighbor 203.202.143.33 validation off
  neighbor 203.202.143.45 activate
  neighbor 203.202.143.45 send-community both
  neighbor 203.202.143.45 route-reflector-client
 exit-address-family
!
ipv6 route 2001:10:10:12::/64 2003::1
ipv6 route 2001:DB8::1/128 2003::1
!
end

End-PE:
DCPR01#show running-config
Building configuration...
!
hostname DCPR01
!
subscriber templating
!
ipv6 unicast-routing
!
flowspec
diagnostic bootup level minimal
!
interface Loopback0
 ip address 203.202.143.45 255.255.255.255
 ip ospf 1 area 0
!
interface TenGigabitEthernet1/3/0
 ip address 10.10.34.4 255.255.255.0
 ip ospf network point-to-point
 ip ospf 1 area 0
 cdp enable
 ipv6 address 2001::1/64
!
router ospf 1
 mpls ldp autoconfig
!
router bgp 7474
 bgp router-id 203.202.143.45
 bgp log-neighbor-changes
 neighbor 203.202.143.44 remote-as 7474
 neighbor 203.202.143.44 update-source Loopback0
 !
 address-family ipv4 flowspec
  neighbor 203.202.143.44 activate
 exit-address-family
 !
 address-family ipv6 flowspec
  neighbor 203.202.143.44 activate
  neighbor 203.202.143.44 validation off
 exit-address-family
!
ipv6 route ::/0 TenGigabitEthernet1/3/0
!
end

Verificar

PE/RR2:
CRR02#ping 2001:db8::1
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 2001:DB8::1, timeout is 2 seconds:
.....
Success rate is 0 percent (0/5)
CRR02#

Controller:
RP/0/RSP0/CPU0:Controller#show bgp ipv6 flowspec
Mon Apr  8 17:55:17.041 UTC
BGP router identifier 10.192.202.5, local AS number 64696
BGP generic scan interval 60 secs
Non-stop routing is enabled
BGP table state: Active
Table ID: 0x0   RD version: 20
BGP main routing table version 20
BGP NSR Initial initsync version 0 (Reached)
BGP NSR/ISSU Sync-Group versions 0/0
BGP scan interval 60 secs

Status codes: s suppressed, d damped, h history, * valid, > best
              i - internal, r RIB-failure, S stale, N Nexthop-discard
Origin codes: i - IGP, e - EGP, ? - incomplete
   Network            Next Hop            Metric LocPrf Weight Path
*> Dest:2001:db8::/0-32/56
                      ::                                     0 i

Processed 1 prefixes, 1 paths
RP/0/RSP0/CPU0:Controller#show flowspec ipv6 detail
Mon Apr  8 17:55:36.786 UTC

AFI: IPv6
  Flow           :Dest:2001:db8::/0-32
    Actions      :Traffic-rate: 0 bps  (policy.1.FS_P.FLOWSPEC)
    Statistics                        (packets/bytes)
      Matched             :                  14/1652
      Dropped             :                  14/1652
RP/0/RSP0/CPU0:BGL14.1.J.05-ASR-9000-1#

PE/RR1:
CRR01#show bgp ipv6 flowspec
BGP table version is 2, local router ID is 203.202.143.33
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
              r RIB-failure, S Stale, m multipath, b backup-path, f RT-Filter,
              x best-external, a additional-path, c RIB-compressed,
              t secondary path,
Origin codes: i - IGP, e - EGP, ? - incomplete
RPKI validation codes: V valid, I invalid, N Not found

     Network          Next Hop            Metric LocPrf Weight Path
 *>   Dest:2001:DB8::/0-32
                      ::                                     0 64696 i
CRR01#
CRR01#show flowspec ipv6 detail
AFI: IPv6
  Flow           :Dest:2001:DB8::/0-32
    Actions      :Traffic-rate: 0 bps  (bgp.1)
    Statistics                        (packets/bytes)
      Matched             :                   4/456
      Dropped             :                   4/456

CRR01#

Troubleshoot

Atualmente, não existem informações disponíveis específicas sobre Troubleshooting para esta configuração.

Tip: Se você abrir um caso com o 3.16.5S e pressionar com o ID do bug CSCva5510. Embora não esteja documentado no bug, ele se aplica ao IPv6. Isso é confirmado do BGP ASR1K e validado. Outro bug CSCvp18767 também é arquivado para o comando show que é corrigido em 16.12.1, portanto é melhor usar essa versão. No entanto, o flowspec do IPv6 pode funcionar em qualquer versão 16.x.