在PfRv2中配置学习列表和PfR映射
目录
简介
本文档介绍如何定义和使用学习列表和映射在性能路由版本2(PfRv2)中，以影响前缀的流量。
先决条件
要求
思科建议您具备PfR的基本知识。
使用的组件
本文档不限于特定的软件和硬件版本。
本文档中的信息都是基于特定实验室环境中的设备编写的。本文档中使用的所有设备最初均采用原始（默认）配置。如果您使用的是真实网络，请确保您已经了解所有命令的潜在影响。
配置
学习列表
PfRv2中的learn-list功能允许路由器学习和分组某些流量类。企业网络由各种类型的流量组成，包括应用、语音、视频等。学习列表可根据网络要求灵活地对此流量进行分组。学习列表中的流量分类和组通常使用与某些特定差分服务代码点(DSCP)值匹配的访问列表来实现，但前缀列表也可用于匹配前缀。这是学习列表的示例，它根据DSCP值“ef”学习和分组流量。
list seq 10 refname Video-Traffic
traffic-class access-list Video
throughput
!
ip access-list extended Video
permit ip any any dscp ef
学习列表可以遵守任何用户定义的策略。这通常通过pfr-map实现。
Pfr-Map
Pfr-map可帮助您定义包含一组参数的策略。然后，通过学习列表分类或分组的流量被映射到pfr映射的单个序列。这些参数可以使用pfr-maps定义。
- 延迟
- 损失
- 无法到达
- 抖动
- 平均意见分数(MOS)
PfR-Map可以有多个序列号，如路由映射，每个序列号可以引用不同的学习列表。
链路组
链路组用于对外部接口进行分组，以便流量可以从所选边界路由器(BR)的送出链路中推出。还可以定义故障切换链路组以在主链路组超出策略时执行切换。例如，此配置以以下方式定义链路组：
set link-group INET fallback MPLS
在序列20下的pfr-map PFR中使用的此配置语句定义了只要INET处于INPOLICY状态，所有要通过INET的DATA流量。如果发生策略违规，流量将故障切换到MPLS链路。
pfr-map PFR 20
set link-group INET fallback MPLS
网络图
此映像为配置示例提供了示例拓扑：
图中所示的设备：
R1服务器 — 启动流量。
R3 - PfR主路由器。
R4和R5 - PfR边界路由器。
连接到R9和R10的客户端是从R1服务器接收流量的设备。
相关配置
在上一个场景中，将配置两个学习列表，一个分别用于应用(APPLICATION-LEARN-LIST)，另一个分别用于数据(DATA-LEARN-LIST)流量。此方案使用前缀列表来定义流量。访问列表也可用于匹配流量类型，如TCP、UDP、Internet控制消息协议(ICMP)等。DSCP、服务类型(ToS)等其他选项也可用于匹配流量。
key chain pfr
key 0
key-string cisco
!
policy-rules PFR
!
border 10.4.4.4 key-chain pfr
interface Ethernet0/0 internal
interface Ethernet0/1 external
link-group MPLS
!
border 10.5.5.5 key-chain pfr
interface Ethernet0/0 internal
interface Ethernet0/1 external
link-group INET
!
learn
traffic-class filter access-list DENY-ALL
list seq 10 refname APPLICATION-LEARN-LIST
traffic-class prefix-list APPLICATION
throughput
list seq 20 refname DATA-LEARN-LIST
traffic-class prefix-list DATA
throughput
!
ip prefix-list DATA
seq 5 permit 10.30.0.0/24
!
ip prefix-list APPLICATION
seq 5 permit 10.20.0.0/24
!
pfr-map PFR 10
match pfr learn list APPLICATION-LEARN-LIST
set periodic 90
set delay threshold 25
set mode monitor active
set resolve delay priority 1 variance 10
set active-probe echo 10.20.0.12
set probe frequency 5
set link-group MPLS fallback INET
!
pfr-map PFR 20
match pfr learn list DATA-LEARN-LIST
set periodic 90
set delay threshold 25
set mode monitor both
set resolve delay priority 1 variance 10
set probe frequency 5
set link-group INET fallback MPLS
验证
当流量通过网络时，它会匹配相应的前缀列表和学习列表。因此，PfR-Map根据为每个学习列表定义的参数对流量执行操作。
第 1 种情况：MPLS和INET云的延迟相同且在策略限制内
前缀10.20.0.0/24（应用）的流量处于INPOLICY状态，并通过链路组MPLS流量。同样，前缀10.30.0.0/24（数据）也处于INPOLICY状态，并通过链路组INET流量。
R3#show pfr master traffic-class
OER Prefix Statistics:
Pas - Passive, Act - Active, S - Short term, L - Long term, Dly - Delay (ms),
P - Percentage below threshold, Jit - Jitter (ms),
MOS - Mean Opinion Score
Los - Packet Loss (percent/10000), Un - Unreachable (flows-per-million),
E - Egress, I - Ingress, Bw - Bandwidth (kbps), N - Not applicable
U - unknown, * - uncontrolled, + - control more specific, @ - active probe all
# - Prefix monitor mode is Special, & - Blackholed Prefix
% - Force Next-Hop, ^ - Prefix is denied
DstPrefix Appl_ID Dscp Prot SrcPort DstPort SrcPrefix
Flags State Time CurrBR CurrI/F Protocol
PasSDly PasLDly PasSUn PasLUn PasSLos PasLLos EBw IBw
ActSDly ActLDly ActSUn ActLUn ActSJit ActPMOS ActSLos ActLLos
--------------------------------------------------------------------------------
10.20.0.0/24 N N N N N N
INPOLICY 50 10.4.4.4 Et0/1 BGP
N N N N N N N N
4 3 0 0 N N N N
10.30.0.0/24 N N N N N N
INPOLICY 0 10.5.5.5 Et0/1 BGP
1 2 0 0 0 0 14 1
1 1 0 0 N N N N
第 2 种情况：MPLS和INET云的延迟不同，且超出策略限制
MPLS云的延迟增加了约150毫秒。这种延迟的增加违反了根据PfR-Map语句设置延迟阈值25配置的25毫秒的阈值延迟值。
这会导致应用流量(10.20.0.0/24)根据已配置的语句集链路组MPLS回退INET故障切换到链路组INET。经过一段时间后，流量再次进入INPOLICY状态并通过链路组INET传输。
R3#show pfr master traffic-class
OER Prefix Statistics:
Pas - Passive, Act - Active, S - Short term, L - Long term, Dly - Delay (ms),
P - Percentage below threshold, Jit - Jitter (ms),
MOS - Mean Opinion Score
Los - Packet Loss (percent/10000), Un - Unreachable (flows-per-million),
E - Egress, I - Ingress, Bw - Bandwidth (kbps), N - Not applicable
U - unknown, * - uncontrolled, + - control more specific, @ - active probe all
# - Prefix monitor mode is Special, & - Blackholed Prefix
% - Force Next-Hop, ^ - Prefix is denied
DstPrefix Appl_ID Dscp Prot SrcPort DstPort SrcPrefix
Flags State Time CurrBR CurrI/F Protocol
PasSDly PasLDly PasSUn PasLUn PasSLos PasLLos EBw IBw
ActSDly ActLDly ActSUn ActLUn ActSJit ActPMOS ActSLos ActLLos
--------------------------------------------------------------------------------
10.20.0.0/24 N N N N N N
INPOLICY 72 10.5.5.5 Et0/1 BGP
N N N N N N N N
2 4 0 0 N N N N
10.30.0.0/24 N N N N N N
INPOLICY 0 10.5.5.5 Et0/1 BGP
1 1 0 0 0 0 14 1
1 1 0 0 N N N N
R3#show pfr master traffic-class performance
Traffic-class:
Destination Prefix : 10.20.0.0/24 Source Prefix : N/A
Destination Port : N/A Source Port : N/A
DSCP : N Protocol : N/A
Application Name: : N/A
General:
Control State : Controlled using BGP
Traffic-class status : INPOLICY
Current Exit : BR 10.5.5.5 interface Et0/1, Tie breaker was delay criteria
Time on current exit : 0d 0:2:40
Time remaining in current state : 31 seconds
Traffic-class type : Learned
Improper config : None
Last Out of Policy event:
Exit : BR 10.5.5.5 interface Et0/1
Reason : delay criteria
Time since Out of Policy event : 0d 0:2:52
Active Delay Performance : 1 msecs
Active Delay Threshold : 25 msecs
Average Active Performance Current Exit: (Average for last 5 minutes)
Unreachable : 0% -- Threshold: 50%
Delay : 1 msec -- Threshold: 25 msec
Last Resolver Decision:
BR Interface Status Reason Performance Threshold
--------------- ------------ ------------ ------------ ----------- ---------
10.4.4.4 Et0/1 Eliminated Delay 162 msecs 25 msecs
10.5.5.5 Et0/1 Best Exit Delay 13 msecs 25 msecs
从输出中，您可以看到MPLS云中的延迟最多有162毫秒的浪涌。这会导致违反策略，因为阈值延迟配置为25毫秒。
实例3：其它WRR加权修改INET云延迟增加100毫秒
这会导致数据流量(10.30.0.0/24)根据已配置的语句集链路组INET回退MPLS故障切换到链路组MPLS。经过一段时间后，流量再次进入INPOLICY状态并通过链路组MPLS流量。
R3#show pfr master traffic-class
OER Prefix Statistics:
Pas - Passive, Act - Active, S - Short term, L - Long term, Dly - Delay (ms),
P - Percentage below threshold, Jit - Jitter (ms),
MOS - Mean Opinion Score
Los - Packet Loss (percent/10000), Un - Unreachable (flows-per-million),
E - Egress, I - Ingress, Bw - Bandwidth (kbps), N - Not applicable
U - unknown, * - uncontrolled, + - control more specific, @ - active probe all
# - Prefix monitor mode is Special, & - Blackholed Prefix
% - Force Next-Hop, ^ - Prefix is denied
DstPrefix Appl_ID Dscp Prot SrcPort DstPort SrcPrefix
Flags State Time CurrBR CurrI/F Protocol
PasSDly PasLDly PasSUn PasLUn PasSLos PasLLos EBw IBw
ActSDly ActLDly ActSUn ActLUn ActSJit ActPMOS ActSLos ActLLos
--------------------------------------------------------------------------------
10.20.0.0/24 N N N N N N
INPOLICY 58 10.4.4.4 Et0/1 BGP
N N N N N N N N
1 2 0 0 N N N N
10.30.0.0/24 N N N N N N
INPOLICY 0 10.4.4.4 Et0/1 BGP
1 1 0 0 0 0 14 1
2 1 0 0 N N N N
R3#show pfr master traffic-class performance
Traffic-class:
Destination Prefix : 10.30.0.0/24 Source Prefix : N/A
Destination Port : N/A Source Port : N/A
DSCP : N Protocol : N/A
Application Name: : N/A
General:
Control State : Controlled using BGP
Traffic-class status : INPOLICY
Current Exit : BR 10.4.4.4 interface Et0/1, Tie breaker was delay criteria
Time on current exit : 0d 0:2:31
Time remaining in current state : 35 seconds
Traffic-class type : Learned
Improper config : None
Last Out of Policy event:
Exit : BR 10.4.4.4 interface Et0/1
Reason : delay criteria
Time since Out of Policy event : 0d 0:2:44
Active Delay Performance : 0 msecs
Active Delay Threshold : 25 msecs
Passive Delay Performance : 9 msecs
Passive Delay Threshold : 25 msecs
Average Passive Performance Current Exit: (Average for last 5 minutes)
Unreachable : 0% -- Threshold: 50%
Delay : 9 msecs -- Threshold: 25 msecs
Loss : 0% -- Threshold: 10%
Egress BW : 4 kbps
Ingress BW : 1 kbps
Time since last update : 0d 0:0:11
Average Active Performance Current Exit: (Average for last 5 minutes)
Unreachable : 0% -- Threshold: 50%
Delay : 0 msec -- Threshold: 25 msec
Last Resolver Decision:
BR Interface Status Reason Performance Threshold
--------------- ------------ ------------ ------------ ----------- ---------
10.5.5.5 Et0/1 Eliminated Delay 96 msecs 25 msecs
10.4.4.4 Et0/1 Best Exit Delay 5 msecs 25 msecs
故障排除
目前没有针对此配置的故障排除信息。
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