Implementing Enhanced Policy Based Routing

This section explains the procedures for configuring Enhanced Policy Based Routing (ePBR) with ACLs, MPLS-TE, and BGP Flow spec.

Configuring ACLs with Enhanced Policy Based Routing

Enhanced Policy based routing (ePBR) is used to direct packets that arrive at an interface to a specified next-hop. ePBR is very useful in managing a large number of configured access lists more efficiently.

In ePBR, the router drops the traffic packets if the next hop configured in the PBR policy is not reachable. To avoid packet loss in such scenarios, you must configure multiple next hops for each access control entry.

Restrictions

  • PBR is not supported on Pseudowire Headend (PHWE) subinterfaces.

  • On Cisco ASR 9000 Series 3rd Generation Line Cards, compressed Access Control Lists (ACLs) are not supported when combined with Policy Based Routing (PBR). However, ACLs without compression can be used with PBR.

Configuration

Use the following sample configuration to configure ACLs with ePBR.

/* Configure an access list */
Router(config)# ipv4 access-list INBOUND-ACL
Router(config-ipv4-acl)# 10 permit ipv4 any host 1.1.1.10
Router(config-ipv4-acl)# 20 permit ipv4 any host 1.2.3.4
Router(config-ipv4-acl)# commit
Mon Nov  6 17:22:42.529 IST
Router(config-ipv4-acl)# exit

/* Configure a class map for the access list */
Router(config)# class-map type traffic match-any INBOUND-CLASS
Router(config-cmap)# match access-group ipv4 INBOUND-ACL
Router(config-cmap)# end-class-map 
Router(config)# commit
Mon Nov  6 17:29:12.026 IST

/* Configure an ePBR policy map with the class map */
Router(config)# policy-map type pbr INBOUND-POLICY
Router(config-pmap)# class type traffic INBOUND-CLASS
Router(config-pmap-c)# redirect nexthop 192.168.10.1
Router(config-pmap-c)# exit
Router(config-pmap)# class type traffic class-default
Router(config-pmap-c)# transmit
Router(config-pmap-c)# commit
Mon Nov  6 17:25:33.858 IST
Router(config-pmap)# end-policy-map 

/* Configure a GigE interface and apply the ePBR policy map to the interface */
Router(config)# interface GigabitEthernet 0/0/0/0
Router(config-if)# ipv4 address 10.10.10.1 255.255.255.0
Router(config-if)# service-policy type pbr input INBOUND-POLICY 
Router(config-if)# commit
Mon Nov  6 17:31:23.645 IST
Router(config-if)# exit

Running Configuration

Validate the configuration by using the show run command. 

Router(config)# show running-config 
Mon Nov  6 17:31:59.015 IST
Building configuration...
!! IOS XR Configuration 0.0.0
!! Last configuration change at Mon Nov  6 17:31:23 2017 by UNKNOWN
!
ipv4 access-list INBOUND-ACL
 10 permit ipv4 any host 1.1.1.10
 20 permit ipv4 any host 1.2.3.4
!
!
class-map type traffic match-any INBOUND-CLASS
 match access-group ipv4 INBOUND-ACL 
 end-class-map
! 
!
policy-map type pbr INBOUND-POLICY
 class type traffic INBOUND-CLASS 
  redirect ipv4 nexthop 192.168.10.1 
 ! 
 class type traffic class-default 
  transmit
 ! 
 end-policy-map
! 
interface GigabitEthernet0/0/0/0
 service-policy type pbr input INBOUND-POLICY
 ipv4 address 10.10.10.1 255.255.255.0
!

Using ePBR for MPLS Packets on Subscriber Interfaces

The enhanced policy based routing (ePBR) match/redirect MPLS packets on subscriber interfaces feature enables the capability to match MPLS labeled packets and redirect those to an external server by re-writing the source and destination IP addresses of the packets. This feature is applicable when the DNS server (an external server) is hidden in the MPLS cloud.

The traffic that is entering the MPLS cloud will be matched for a specific destination address and based on it, the new destination will be set. When the packet returns from the DNS server, the source address is changed back to the original source address.

Use Case: Using ePBR for MPLS Packets on Subscriber Interfaces

The ePBR match/redirect MPLS packets on subscriber Interfaces feature is applicable when a packet arrives at an interface with a destination address of a known server. This feature changes the known destination address to a required address that is hidden in the DNS cloud. For example, when the packet reaches a known interface with a specific IP address, say 10.0.0.1, it can to be redirected to a new IP address, say 172.16.0.1 , that is hidden in the cloud.

For subscriber to core DNS packets, the sequence for match and redirect is:

  • Match the incoming packet for the known DNS server. This address could be a local address on the Cisco ASR 9000 Series Router, which the subscriber uses as DNS server address.

  • Set the destination address to a new IP address to which the packet has to be redirected.

This figure explains the match and redirect sequence for subscriber to core DNS packets.
Figure 1. Subscriber to core DNS packets


For core to subscriber DNS packets, the sequence for match and redirect is :

  • Match the incoming labeled DNS packet's source IP address from the core.

  • Set the source address to a local address, which the subscriber uses as DNS server address. The packet would be forwarded based on label + destination IP address, which is the subscriber address.

This figure explains the match and redirect sequence for core to subscriber DNS packets.
Figure 2. Core to subscriber DNS packets


Configuring ePBR-Based MPLS Redirection

These examples show how to configure ePBR-based MPLS match/redirect configuration.

Match configuration for IPv4 packets: 

policy-map type pbr policy_mpls_src_test
class type traffic class_mpls_src_test
  set source-address ipv4 17.17.18.18
!
class type traffic class-default
 !
end-policy-map
!
 
RP/0/RSP0/CPU0:ASR9K-0#show running-config class-map type traffic class_mpls_src_test
Wed Sep  3 02:52:31.411 UTC
class-map type traffic match-any class_mpls_src_test
match mpls disposition access-group ipv4 ACL_MPLS_SRC
 end-class-map
!
 
show running-config ipv4 access-list ACL_MPLS_SRC
Wed Sep  3 02:53:40.918 UTC
ipv4 access-list ACL_MPLS_SRC
10 permit ipv4 30.1.1.1/24 112.112.0.1/24
!
Match configuration for IPv6 packets: 
policy-map type pbr policy_mpls_src_test
class type traffic class_mpls_ipv6_src_test
  set source-address ipv4 10.10.10.10
!
class type traffic class-default
 !
end-policy-map
!
 
RP/0/RSP0/CPU0:ASR9K-0# show running-config class-map type traffic class_mpls_ipv6_src_test
Wed Sep  3 02:52:31.411 UTC
class-map type traffic match-any class_mpls_ipv6_src_test
match mpls disposition access-group ipv6 ACL_MPLS_IPV6__SRC
 end-class-map
!
 
show running-config ipv6 access-list ACL_MPLS_IPV6_SRC
Wed Sep  3 02:53:40.918 UTC
Ipv6 access-list ACL_MPLS_IPV6_SRC
10 permit ipv6 any any
!
Set destination configuration: 

show running-config policy-map type pbr pbr_prec_exp
Wed Sep  3 03:11:16.000 UTC
policy-map type pbr pbr_prec_exp
class type traffic class_prec_exp
  set destination-address ipv4 192.168.0.1
!
class type traffic class-default
 !
end-policy-map
!
 
RP/0/RSP0/CPU0:ASR9K-0#show running-config class-map type traffic class_prec_e$
Wed Sep  3 03:11:30.339 UTC
class-map type traffic match-all class_prec_exp
match mpls experimental topmost 2
 match mpls disposition access-group ipv4 acl2
 end-class-map
!
 
RP/0/RSP0/CPU0:ASR9K-0# show running-config ipv4 access-list acl2
Wed Sep  3 03:11:47.963 UTC
ipv4 access-list acl2
5 permit ipv4 host 10.10.10.10 any
10 permit ipv4 any any
!

BGP Flowspec Client-Server (Controller) Model and Configuration with ePBR

The BGP Flowspec model comprises of a Client and a Server (Controller). The Controller is responsible for sending or injecting the flowspec NRLI entry. The client (acting as a BGP speaker) receives that NRLI and programs the hardware forwarding to act on the instruction from the Controller. An illustration of this model is provided below.

BGP Flowspec Client

Here, the Controller on the left-hand side injects the flowspec NRLI, and the client on the right-hand side receives the information, sends it to the flowspec manager, configures the ePBR (Enhanced Policy-based Routing) infrastructure, which in turn programs the hardware from the underlaying platform in use.

BGP Flowspec Controller

The Controller is configured using CLI to provide that entry for NRLI injection.

BGP Flowspec Configuration

  • BGP-side: You must enable the new address family for advertisement. This procedure is applicable for both the Client and the Controller. Enable BGP Flowspec explains the procedure.

    Client-side: No specific configuration, except availability of a flowspec-enabled peer.

  • Controller-side: This includes the policy-map definition and the association to the ePBR configuration consists of two procedures: the class definition, and using that class in ePBR to define the action. The following topics explain the procedure:

Configuring BGP Flowspec with ePBR

The following sections explain the procedures for configuring BGP flowspec with ePBR.

Use the following procedures to enable and configure the BGP flowspec feature:


Note
To save configuration changes, you must commit changes when the system prompts you.

Enable BGP Flowspec

You must enable the address family for propagating the BGP flowspec policy on both the Client and Server using the following steps:

SUMMARY STEPS

  1. configure
  2. router bgp as-number
  3. address-family { ipv4 | ipv6 | vpnv4 | vpnv6 } flowspec
  4. exit
  5. neighbor ip-address
  6. remote-as as-number
  7. address-family { ipv4 | ipv6 } flowspec

DETAILED STEPS

  Command or Action Purpose

Step 1

configure

Step 2

router bgp as-number

Example:

RP/0/RSP0/CPU0:router(config)# router bgp 100

Specifies the autonomous system number and enters the BGP configuration mode, allowing you to configure the BGP routing process.

Step 3

address-family { ipv4 | ipv6 | vpnv4 | vpnv6 } flowspec

Example:

RP/0/RSP0/CPU0:router(config-bgp)# address-family ipv4 flowspec

Specifies either the IPv4, IPv6, vpn4 or vpn6 address family and enters address family configuration submode, and initializes the global address family for flowspec policy mapping.

Step 4

exit

Example:

RP/0/RSP0/CPU0:router(config-bgp-af)# exit

Returns the router to BGP configuration mode.

Step 5

neighbor ip-address

Example:
RP/0/RSP0/CPU0:router(config-bgp)#neighbor 1.1.1.1

Places the router in neighbor configuration mode for BGP routing and configures the neighbor IP address as a BGP peer.

Step 6

remote-as as-number

Example:
RP/0/RSP0/CPU0:router(config-bgp-nbr)#remote-as 100

Assigns a remote autonomous system number to the neighbor.

Step 7

address-family { ipv4 | ipv6 } flowspec

Example:

RP/0/RSP0/CPU0:router(config-bgp)# address-family ipv4 flowspec

Specifies an address family and enters address family configuration submode, and initializes the global address family for flowspec policy mapping.

Configuring an address family for flowspec policy mapping: Example 
router bgp 100

 address-family ipv4 flowspec

 ! Initializes the global address family

 address-family ipv6 flowspec

 !

 neighbor 1.1.1.1

  remote-as 100

  address-family ipv4 flowspec

  ! Ties it to a neighbor configuration

  address-family ipv6 flowspec

  !

Configure a Class Map

In order to associate the ePBR configuration to BGP flowspec you must perform these sub-steps: define the class and use that class in ePBR to define the action. The steps to define the class include:

SUMMARY STEPS

  1. configure
  2. class-map [type traffic] [match-all] class-map-name
  3. match match-statement
  4. end-class-map

DETAILED STEPS

  Command or Action Purpose

Step 1

configure

Step 2

class-map [type traffic] [match-all] class-map-name

Example:

RP/0/RSP0/CPU0:router(config)# class-map type traffic match all classc1

Creates a class map to be used for matching packets to the class whose name you specify and enters the class map configuration mode. If you specify match-any , one of the match criteria must be met for traffic entering the traffic class to be classified as part of the traffic class. This is the default. If you specify match-all , the traffic must match all the match criteria.

Step 3

match match-statement

Example:

RP/0/RSP0/CPU0:router(config-cmap)# match protocol ipv4 1 60

Configures the match criteria for a class map on the basis of the statement specified. Any combination of tuples 1-13 match statements can be specified here. The tuple definition possibilities include:

  • Type 1: match destination-address {ipv4 | ipv6} address/mask length
  • Type 2: match source-address {ipv4 | ipv6} address/mask length
  • Type 3: match protocol { protocol-value | min-value - max-value}

    Note

     

    In case of IPv6, it will map to last next-header.

  • Type 4: Create two class-maps: one with source-port and another with destination-port:
    • match source-port { source-port-value | min-value - max-value}

      Note

       

      Only up to 5 port numbers are supported in a single match string.
    • match destination-port { destination-port-value | min-value - max-value}

      Note

       

      These are applicable only for TCP and UDP protocols.

  • Type 5: match destination-port {destination-port-value | [min-value - max-value]}
  • Type 6: match source-port {source-port-value | [min-value - max-value]}
  • Type 7: match { ipv4 | ipv6} icmp-code {value | min-value - max-value}
  • Type 8: match { ipv4 | ipv6} icmp-type {value | min-value - max-value}
  • Type 9: match tcp-flag value bit-mask mask_value
  • Type 10: match packet length { packet-length-value | min-value - max-value} }
  • Type 11: match dscp { dscp-value | min-value - max-value}
  • Type 12: match fragment-type { dont-fragment is-fragment first-fragment last-fragment}
  • Type 13: match ipv6 flow-label ipv4 flow-label { value | min-value - max-value}

BGP Flowspec Commands in the Routing Command Reference for Cisco ASR 9000 Series Routers guide provides additional details on the various commands used for BGP flowspec configuration.

Step 4

end-class-map

Example:

RP/0/RSP0/CPU0:router(config-cmap)# end-class-map

Ends the class map configuration and returns the router to global configuration mode.

What to do next

Associate the class defined in this procedure to a PBR policy as described in Configure a Policy Map.

Configure a Policy Map

This procedure helps you define a policy map and associate it with traffic class you configured previously in Configure a Class Map .

SUMMARY STEPS

  1. configure
  2. policy-map type pbr policy-map
  3. class class-name
  4. class type traffic class-name
  5. action
  6. exit
  7. end-policy-map

DETAILED STEPS

  Command or Action Purpose

Step 1

configure

Step 2

policy-map type pbr policy-map

Example:

RP/0/RSP0/CPU0:router(config)# policy-map type pbr policyp1

Creates or modifies a policy map that can be attached to one or more interfaces to specify a service policy and enters the policy map configuration mode.

Step 3

class class-name

Example:

RP/0/RSP0/CPU0:router(config-pmap)# class class1

Specifies the name of the class whose policy you want to create or change.

Step 4

class type traffic class-name

Example:

RP/0/RSP0/CPU0:router(config-pmap)# class type traffic classc1

Associates a previously configured traffic class with the policy map, and enters control policy-map traffic class configuration mode.

Step 5

action

Example:

RP/0/RSP0/CPU0:router(config-pmap-c)# set dscp 5
Define extended community actions as per your requirement. The options include:

  • Traffic rate: police rate rate

  • Redirect VRF: redirect { ipv4ipv6 } extcommunity rt route_target_string

  • Traffic Marking: set { dscp rate | destination-address {ipv4 | ipv6} 8-bit value}

  • Redirect IP NH: redirect { ipv4ipv6 } nexthop ipv4 addressipv6 address { ipv4 addressipv6 address}

Step 6

exit

Example:

RP/0/RSP0/CPU0:router(config-pmap-c)# exit

Returns the router to policy map configuration mode.

Step 7

end-policy-map

Example:

RP/0/RSP0/CPU0:router(config-cmap)# end-policy-map

Ends the policy map configuration and returns the router to global configuration mode.

What to do next

Perform VRF and flowspec policy mapping for distribution of flowspec rules using the procedure explained in Link BGP Flowspec to ePBR Policies

Link BGP Flowspec to ePBR Policies

For BGP flowspec, an ePBR policy is applied on a per VRF basis, and this policy is applied on all the interfaces that are part of the VRF. If you have already configured a ePBR policy on an interface, it will not be overwritten by the BGP flowspec policy. If you remove the policy from an interface, ePBR infrastructure will automatically apply BGP flowspec policy on it, if one was active at the VRF level.

Note

At a time only one ePBR policy can be active on an interface.

SUMMARY STEPS

  1. configure
  2. flowspec
  3. local-install interface-all
  4. address-family ipv4
  5. local-install interface-all
  6. service-policy type pbr policy-name
  7. exit
  8. address-family ipv6
  9. local-install interface-all
  10. service-policy type pbr policy-name
  11. vrf vrf-name
  12. address-family ipv4
  13. local-install interface-all
  14. service-policy type pbr policy-name
  15. exit
  16. address-family ipv6
  17. local-install interface-all
  18. service-policy type pbr policy-name
  19. commit
  20. exit
  21. show flowspec { afi-all | client | ipv4 | ipv6 | summary | vrf

DETAILED STEPS

  Command or Action Purpose

Step 1

configure

Step 2

flowspec

Example:

RP/0/RSP0/CPU0:router(config)# flowspec

Enters the flowspec configuration mode.

Step 3

local-install interface-all

Example:

RP/0/RSP0/CPU0:router(config-flowspec)# local-install interface-all

(Optional) Installs the flowspec policy on all interfaces.

Step 4

address-family ipv4

Example:

RP/0/RSP0/CPU0:router(config-flowspec)# address-family ipv4

Specifies either an IPv4 address family and enters address family configuration submode.

Step 5

local-install interface-all

Example:

RP/0/RSP0/CPU0:router(config-flowspec-af)# local-install interface-all

(Optional) Installs the flowspec policy on all interfaces under the subaddress family.

Step 6

service-policy type pbr policy-name

Example:

RP/0/RSP0/CPU0:router(config-flowspec-af)# service-policy type pbr policys1

Attaches a policy map to an IPv4 interface to be used as the service policy for that interface.

Step 7

exit

Example:

RP/0/RSP0/CPU0:router(config-flowspec-af)# exit

Returns the router to flowspec configuration mode.

Step 8

address-family ipv6

Example:

RP/0/RSP0/CPU0:router(config-flowspec)# address-family ipv6

Specifies an IPv6 address family and enters address family configuration submode.

Step 9

local-install interface-all

Example:

RP/0/RSP0/CPU0:router(config-flowspec-af)# local-install interface-all

(Optional) Installs the flowspec policy on all interfaces under the subaddress family.

Step 10

service-policy type pbr policy-name

Example:

RP/0/RSP0/CPU0:router(config-flowspec-af)# service-policy type pbr policys1

Attaches a policy map to an IPv6 interface to be used as the service policy for that interface.

Step 11

vrf vrf-name

Example:

RP/0/RSP0/CPU0:router(config-flowspec)# vrf vrf1

Configures a VRF instance and enters VRF flowspec configuration submode.

Step 12

address-family ipv4

Example:

RP/0/RSP0/CPU0:router(config-flowspec-vrf)# address-family ipv4

Specifies an IPv4 address family and enters address family configuration submode.

Step 13

local-install interface-all

Example:

RP/0/RSP0/CPU0:router(config-flowspec-vrf-af)# local-install interface-all

(Optional) Installs the flowspec policy on all interfaces under the subaddress family.

Step 14

service-policy type pbr policy-name

Example:

RP/0/RSP0/CPU0:router(config-flowspec-vrf-af)# service-policy type pbr policys1

Attaches a policy map to an IPv4 interface to be used as the service policy for that interface.

Step 15

exit

Example:

RP/0/RSP0/CPU0:router(config-flowspec-vrf-af)# exit

Returns the router to VRF flowspec configuration submode.

Step 16

address-family ipv6

Example:

RP/0/RSP0/CPU0:router(config-flowspec-vrf)# address-family ipv6

Specifies either an IPv6 address family and enters address family configuration submode.

Step 17

local-install interface-all

Example:

RP/0/RSP0/CPU0:router(config-flowspec-vrf-af)# local-install interface-all

(Optional) Installs the flowspec policy on all interfaces under the subaddress family.

Step 18

service-policy type pbr policy-name

Example:

RP/0/RSP0/CPU0:router(config-flowspec-vrf-af)# service-policy type pbr policys1

Attaches a policy map to an IPv6 interface to be used as the service policy for that interface.

Step 19

commit

Step 20

exit

Example:

RP/0/RSP0/CPU0:router(config-flowspec-vrf-af)# exit

Returns the router to flowspec configuration mode.

Step 21

show flowspec { afi-all | client | ipv4 | ipv6 | summary | vrf

Example:

RP/0/RSP0/CPU0:routershow flowspec vrf vrf1 ipv4 summary

(Optional) Displays flowspec policy applied on an interface.

Verify BGP Flowspec

Use these different show commands to verify your flowspec configuration. For instance, you can use the associated flowspec and BGP show commands to check whether flowspec rules are present in your table, how many rules are present, the action that has been taken on the traffic based on the flow specifications you have defined and so on.

SUMMARY STEPS

  1. show processes flowspec_mgr location all
  2. show flowspec summary
  3. show flowspec vrf vrf_name | all { afli-all | ipv4 | ipv6 }
  4. show bgp ipv4 flowspec

DETAILED STEPS

  Command or Action Purpose

Step 1

show processes flowspec_mgr location all

Example:

# show processes flowspec_mgr location all
node:      node0_3_CPU0
-------------------------------------------------------------------------
Job Id: 10                   
PID: 43643169
Executable path: /disk0/iosxr-fwding-5.2.CSC33695-015.i/bin/flowspec_mgr
Instance #: 1
Version ID: 00.00.0000
Respawn: ON
Respawn count: 331
Max. spawns per minute: 12
Last started: Wed Apr  9 10:42:13 2014
Started on config: cfg/gl/flowspec/
Process group: central-services core: MAINMEM 
startup_path: /pkg/startup/flowspec_mgr.startup
Ready: 1.113s
Process cpu time: 0.225 user, 0.023 kernel, 0.248 total
JID   TID CPU Stack pri state    TimeInState    HR:MM:SS:MSEC   NAME
1082   1    0  112K  10 Receive    2:50:23:0508  0:00:00:0241 flowspec_mgr
1082   2    1  112K  10 Sigwaitinfo 2:52:42:0583   0:00:00:0000 flowspec_mgr

Specifies whether the flowspec process is running on your system or not. The flowspec manager is responsible for creating, distributing and installing the flowspec rules on the hardware.

Step 2

show flowspec summary

Example:

# show flowspec summary

FlowSpec Manager Summary:
  Tables:                          2
  Flows:                           1
RP/0/3/CPU0:RA01_R4#

Provides a summary of the flowspec rules present on the entire node. In this example, the 2 table indicate that IPv4 and IPv6 has been enabled, and a single flow has been defined across the entire table.

Step 3

show flowspec vrf vrf_name | all { afli-all | ipv4 | ipv6 }

Example:


# show flowspec vrf default ipv4 summary

Flowspec VRF+AFI table summary:
VRF: default
  AFI: IPv4
    Total Flows:              1
    Total Service Policies:   1
RP/0/3/CPU0:RA01_R4#
---------------------------------------------------
# show flowspec vrf default ipv6 summary

Flowspec VRF+AFI table summary:
VRF: default
  AFI: IPv6
    Total Flows:              0
    Total Service Policies:   0
RP/0/3/CPU0:RA01_R4#
---------------------------------------------------
# show flowspec vrf all afi-all summary

Flowspec VRF+AFI table summary:
VRF: default
  AFI: IPv4
    Total Flows:              1
    Total Service Policies:   1
VRF: default
  AFI: IPv6
    Total Flows:              0
    Total Service Policies:   0
--------------------------------------------------
# show flowspec vrf default ipv4 Dest:110.1.1.0/24,
Source:10.1.1.0/24,DPort:>=120&<=130,
SPort:>=25&<=30,DSCP:=30 detail

AFI: IPv4
 Flow           :Dest:110.1.1.0/24,Source:10.1.1.0/24,
DPort:>=120&<=130,SPort:>=25&<=30,DSCP:=30
  Actions       :Traffic-rate: 0 bps  (bgp.1)
  Statistics                        (packets/bytes)
   Matched             :                   0/0
   Transmitted         :                   0/0
   Dropped             :                   0/0

In order to obtain more granular information on the flowspec, you can filter the show commands based on a particular address-family or by a specific VRF name. In this example, 'vrf default' indicates that the flowspec has been defined on the default table. The 'IPv4 summary' shows the IPv4 flowspec rules present on that default table. As there are no IPv6s configured, the value shows 'zero' for ipv6 summary 'Table Flows' and 'Policies' parameters. 'VRF all' displays information across all the VRFs configured on the table and afli-all displays information for all address families (IPv4 and IPv6).

The detail option displays the 'Matched', 'Transmitted, ' and 'Dropped' fields. These can be used to see if the flowspec rule you have defined is in action or not. If there is any traffic that takes this match condition, it indicates if any action has been taken (that is, how many packets were matched and whether these packets have been transmitted or dropped.

Step 4

show bgp ipv4 flowspec

Example:

# show bgp ipv4 flowspec Dest:110.1.1.0/24,Source:10.1.1.0/24,
DPort:>=120&<=130,SPort:>=25&<=30,DSCP:=30/208
BGP routing table entry for Dest:110.1.1.0/24,
Source:10.1.1.0/24,Proto:=47,DPort:>=120&<=130,SPort:>=25&<=30,DSCP:=30/208
<snip>
Paths: (1 available, best #1)
  Advertised to update-groups (with more than one peer):
    0.3
  Path #1: Received by speaker 0
  Advertised to update-groups (with more than one peer):
    0.3
  Local
    0.0.0.0 from 0.0.0.0 (3.3.3.3)
      Origin IGP, localpref 100, valid, redistributed, best, group-best
      Received Path ID 0, Local Path ID 1, version 42
      Extended community: FLOWSPEC Traffic-rate:100,0

Use this command to verify if a flowspec rule configured on the controller router is available on the BGP side. In this example, 'redistributed' indicates that the flowspec rule is not internally originated, but one that has been redistributed from the flowspec process to BGP. The extended community (BGP attribute used to send the match and action criteria to the peer routers) you have configured is also displayed here. In this example, the action defined is to rate limit the traffic.

Supported Match and Set Operations—ABF, ePBR/Flowspec, and PBR

The following table illustrates the match/set criteria that is supported by ABF, ePBR/Flowspec, and PBR:

Table 1. Supported Match and Set Operations

match/set criteria

ABF

ePBR/Flowspec

PBR

source ip

match

match

match

destination ip

match

match

match

source protocol/port

match

match

match

destination protocol/port

match

match

match

nexthop ip

set

set

set

nexthop vrf

set

set

set

nexthop ip+vrf

set

NA

set

dscp

NA

match/set

NA

forward-class

NA

NA

set

police

NA

set

NA

access-group

NA

NA

match

flow-tag

NA

NA

match

fragment-type

NA

match

NA

packet length

NA

match

NA

ip protocol

match

match

match

tcp-flag

match

match

match

ipv4/ipv6 icmp-type

NA

match

NA

ipv4/ipv6 icmp-code

NA

match

NA

port

NA

match

NA

port-range

match

match

match

Additional References

The following sections provide references related to configuring NSR, TCP, and UDP transports.

Related Documents

Related Topic

Document Title

the Cisco ASR 9000 Series Router Transport Stack commands: complete command syntax, command modes, command history, defaults, usage guidelines, and examples

Transport Stack Commands in the IP Addresses and Services Command Reference for Cisco ASR 9000 Series Routers

the Cisco ASR 9000 Series Router MPLS LDP commands: complete command syntax, command modes, command history, defaults, usage guidelines, and examples

MPLS Label Distribution Protocol Commands in the MPLS Command Reference for Cisco ASR 9000 Series Routers

the Cisco ASR 9000 Series Router OSPF commands: complete command syntax, command modes, command history, defaults, usage guidelines, and examples

OSPF Commands in the Routing Command Reference for Cisco ASR 9000 Series Routers

MPLS Label Distribution Protocol feature information

Implementing MPLS Label Distribution Protocol in the MPLS Configuration Guide for Cisco ASR 9000 Series Routers

OSPF feature information

Implementing OSPF in the Routing Configuration Guide for Cisco ASR 9000 Series Routers

Standards

Standards

Title

No new or modified standards are supported by this feature, and support for existing standards has not been modified by this feature.

—

MIBs

MIBs

MIBs Link
—

To locate and download MIBs, use the Cisco MIB Locator found at the following URL and choose a platform under the Cisco Access Products menu: https://mibs.cloudapps.cisco.com/ITDIT/MIBS/servlet/index

RFCs

RFCs

Title

No new or modified RFCs are supported by this feature, and support for existing RFCs has not been modified by this feature.

 —

Technical Assistance

Description

Link

The Cisco Technical Support website contains thousands of pages of searchable technical content, including links to products, technologies, solutions, technical tips, and tools. Registered Cisco.com users can log in from this page to access even more content.

http://www.cisco.com/techsupport