帮助我们改善您的体验。

让我们了解您的想法。

您是否能抽出两分钟的时间完成一份问卷调查?

external-header-nav
keyboard_arrow_up
list Table of Contents
keyboard_arrow_right

机器翻译对您有帮助吗?

starstarstarstarstar
Go to English page
免责声明:

我们将使用第三方机器翻译软件翻译本页面。瞻博网络虽已做出相当大的努力提供高质量译文,但无法保证其准确性。如果对译文信息的准确性有任何疑问,请参阅英文版本. 可下载的 PDF 仅提供英文版.

示例:基于多个 LSP 配置的第 2 层 电路流量工程

date_range 02-Aug-23
图 1:第 2 层 电路流量工程拓扑图 Layer 2 Circuit Traffic Engineering Topology Diagram

图 1 显示了一种网络拓扑,该拓扑旨在通过选定的 LSP 对不同的第 2 层 电路进行流量工程。 在提供商边缘路由器 PE1 和 PE2 中,ATM AAL5 模式第 2 层 电路连接客户边缘路由器 CE1 和 CE2,帧中继第 2 层 电路连接路由器 CE3 和 CE4。为了保持流量分离,ATM 流量映射到具有名为 的gold社区的 LSP1,帧中继流量映射到具有名为 silver的社区的 LSP2 上。LSP1 采用路由器 PE1 和 PE2 之间的直接路由,而 LSP2 通过路由器 P0 从路由器 PE1 传输到 PE2。

除了流量工程之外,您还可以在第 2 层 电路的控制字中发送第 2 层 控制信息。在这种情况下,帧中继丢弃合格 (DE)、前向显式拥塞通知 (FECN) 和后向显式拥塞通知 (BECN) 信息将映射到控制字中。同样,ATM 信元丢失优先级 (CLP) 和显式前向拥塞指示器 (EFCI) 信息也映射到控制字中。

要在多个 LSP 上对第 2 层 电路进行流量工程,请将一组第 2 层 电路分配给社区,然后应用策略通过所需的 LSP 发送社区流量。要创建社区,请在层次结构级别包含communitycommunity-name语句[edit policy-options]。要将第 2 层 电路分配给社区,请在层次结构级别包含community community-name语句[edit protocols l2circuit neighbor neighbor-id interface interface-name]。要通过特定 LSP 发送社区流量,请在层次结构级别包含[edit policy-options policy-statement policy-name term term-name from] 语句,install-next-hop lsp lsp-name在层次结构级别包含community community-name语句[edit policy-options policy-statement policy-name term term-name then]

在路由器 CE1 上,配置 ATM2 IQ 接口 at-0/0/1.32 以处理 ATM AAL5 流量:

路由器 CE1

content_copy zoom_out_map
[edit]
interfaces {
    at-0/0/1 {
        description "to PE1 at-1/1/0";
        atm-options {
            pic-type atm2; # Layer 2 circuits are compatible with
            vpi 0; # ATM2 IQ interfaces.
        }
        unit 0 {
            encapsulation atm-vc-mux; # Use ATM VC MUX encapsulation on the CE.
            point-to-point;
            vci 0.32;
            family inet {
                address 10.0.0.1/30;
            }
        }
    }
}

在路由器 CE3 上,配置 SONET/SDH 接口 so-0/0/1 以处理帧中继流量:

路由器 CE3

content_copy zoom_out_map
[edit]
interfaces
so-0/0/1 {
    description “to PE1 so-1/1/1” 
    encapsulation frame-relay; # Use Frame Relay encapsulation on the CE router.
    unit 0 {
        encapsulation frame-relay;
        point-to-point;
        dlci 512;
        family inet {
            address 10.10.0.1/30;
        }
    }
}

在路由器 PE1 上,配置基于 ATM2 IQ 的面向 CE1 的接口at-1/1/0,并在逻辑接口上配置带有 ATM VC 多路复用 CCC 封装。还要在[edit chassis]层次结构级别启用相应的第 2 层 电路模式。在这种情况下,您必须在 FPC 1. 中的 PIC 1 上配置 AAL5 模式 配置基于 ATM2 IQ 的第 2 层 电路后,默认情况下,CLP 和 EFCI 位将映射到控制字。

接下来,在物理和逻辑接口上配置具有帧中继 CCC 封装的帧中继接口so-1/1/1。在层次结构级别使用 [edit interfaces so-fpc/pic/port unit unit-number family ccc] and translate-discard-eligible 语句将 translate-fecn-and-becn DE、FECN 和 BECN 位映射到控制字。

通过在层次结构级别配置[edit protocols]语句来l2circuit建立第 2 层 电路。请记住在第 2 层 电路配置中包含远程 PE 邻居的 IP 地址(通常是邻居的环路地址)、连接到客户边缘 路由器的接口以及每个 VC 的虚拟电路标识符。在这种情况下,您将为 ATM AAL5 流量建立一个 VC,为帧中继流量建立另一个 VC。然后,配置 MPLS、LDP 和 IGP(例如 OSPF),为第 2 层 电路启用信令。为 ATM 和帧中继流量建立了两个 LSP:LSP1 用于直接进入路由器 PE2 的 ATM 流量,LSP 2 用于在进入路由器 PE2 之前通过路由器 P0 的帧中继流量。

最后,为 ATM 和帧中继第 2 层 电路配置流量分离社区。将社区分配给 ATM VC,将社区goldsilver分配给帧中继 VC。请记住为社区提供数值并配置路由策略以将社区与特定 LSP 匹配。此策略作为策略应用于export层次结构级别的转发表[edit routing-options]

路由器 PE1

content_copy zoom_out_map
[edit]
chassis {
    fpc 1 {
        pic 1 {
            atm-l2circuit-mode {
                aal5; # This dedicates FPC 1 PIC 1 to AAL5 mode.
            }
        }
    }
}
interfaces {
    at-1/1/0 {
        description "to CE1 at-0/0/2";
        atm-options {
            pic-type atm2; # Layer 2 circuits are compatible with
            vpi 0; # ATM2 IQ interfaces.
        }
        unit 0 {
            encapsulation atm-ccc-vc-mux; # CLP/EFCI bits are mapped to control word.
            vci 0.32;
        }
    }
    so-0/1/0 {
        description "to P0 so-0/0/0";
        unit 0 {
            family inet {
                address 192.168.27.17/30;
            }
            family mpls; # Include the MPLS family on core-facing interfaces.
        }
    }
    so-1/1/0 {
        description "to PE2 so-1/0/1";
        unit 0 {
            family inet {
                address 192.168.27.10/30;
            }
            family mpls; # Include the MPLS family on core-facing interfaces.
        }
    }
    so-1/1/1 {
        description "to CE3 so-0/0/1";
        dce;
        encapsulation frame-relay-ccc;
        unit 0 {
            encapsulation frame-relay-ccc;
            point-to-point;
            dlci 512;
            family ccc {
                translate-fecn-and-becn; # Option to map FECN/BECN bits to control word.
                translate-discard-eligible; # Option to map DE bit to control word.
            }
        }
    }
    lo0 {
        unit 0 {
            family inet {
                address 10.255.17.2/32;
            }
        }
    }
}
routing-options {
    forwarding-table {
        export layer2communities; # This applies communities to the Layer 2 circuits.
    }
}
protocols {
    mpls {
        label-switched-path lsp1 { # ATM LSP 1 goes directly to PE2.
            to 10.255.17.4;
            primary direct;
        }
        label-switched-path lsp2 { # Frame Relay LSP 2 goes through P0.
            to 10.255.17.4;
            primary thruP0;
        }
        path direct {
            192.168.27.9 strict;
        }
        path thruP0 {
            192.168.27.18 strict;
            192.168.27.25 strict;
        }
        interface so-0/0/1.0;
        interface so-1/1/0.0;
    }
    ospf {
        traffic-engineering;
        area 0.0.0.0 {
            interface so-0/0/1.0;
            interface so-1/1/0.0;
            interface lo0.0;
        }
    }
    ldp { # LDP is required as the signaling protocol for Layer 2 circuits.
        interface so-0/0/1.0;
        interface so-1/1/0.0;
        interface lo0.0;
    }
    l2circuit {
        neighbor 10.255.17.4 {# This points to the loopback of the PE neighbor.
            interface at-1/1/0.32 { # Here you include the local CE-facing interface.
                virtual-circuit-id 1; # Be sure this ID matches the ID of your PE neighbor.
                community gold;# Assigns the ATM Layer 2 circuit to the gold community.
            }
        }
        neighbor 10.255.17.4 {# This points to the loopback of the PE neighbor.
            interface so-1/1/1.512 { # Here you include the local CE-facing interface.
                virtual-circuit-id 2; # Be sure this ID matches the ID of your PE neighbor.
                community silver; # Assigns the Frame Relay Layer 2 circuit to silver.
            }
        }
    }
}
policy-options {
    policy-statement layer2communities { # Here you map the communities to LSPs.
        term 10 {
            from community gold;  # Apply community gold to LSP 1.
            then {
                install-nexthop lsp lsp1; 
                accept;
            }
        }
        term 20 {
            from community silver; # Apply community silver to LSP 2.
            then {
                install-nexthop lsp lsp2; 
                accept;
            }
        }
    }
    community gold members 103:1; # Assign numerical value to community gold.
    community silver members 103:2; # Assign numerical value to community silver.
}

在路由器 P0 上,在连接到 PE 路由器的接口上配置 LDP、MPLS 和 OSPF。核心路由器提供将第 2 层 流量从入口 PR 路由器隧道传输到出口 PE 路由器所需的 MPLS 主干网。只有用于帧中继的 LSP 2 通过路由器 P0。

路由器 P0

content_copy zoom_out_map
[edit]
interfaces {
    so-1/1/1 {
        description "to PE1 so-0/0/1";
        unit 0 {
            family inet {
                address 192.168.27.18/30;
            }
            family mpls; # Include the MPLS family on core interfaces.
        }
    }
    so-1/1/2 {
        description "to PE2 so-0/1/1";
        unit 0 {
            family inet {
                address 192.168.27.26/30;
            }
            family mpls; # Include the MPLS family on core interfaces.
        }
    }
    lo0 {
        unit 0 {
            family inet {
                address 10.255.17.3/32;
            }
        }
    }
}
protocols {
    mpls {               
        interface so-1/1/1.0;
        interface so-1/1/2.0;
    }
    ospf {
        traffic-engineering;
        area 0.0.0.0 {
            interface so-1/1/1.0;
            interface so-1/1/2.0;
        }
    }
    ldp {# LDP is required as the signaling protocol for Layer 2 circuits.
        interface so-1/1/1.0;
        interface so-1/1/2.0;
    }
}

在路由器 PE2 上,通过配置语句以匹配之前在路由器 PE1 上设置的语句来完成第 2 层 电路。

通过在层次结构级别配置[edit protocols]语句来l2circuit建立第 2 层 电路。请记住在第 2 层 电路配置中包含远程 PE 邻居的 IP 地址(通常是邻居的环路地址)、连接到客户边缘路由器的接口以及每个 VC 的虚拟电路标识符。在这种情况下,您将为 ATM AAL5 流量建立一个 VC,为帧中继流量建立另一个 VC。然后,配置 MPLS、LDP 和 IGP(例如 OSPF),为第 2 层 电路启用信令。为 ATM 和帧中继流量建立了两个 LSP:LSP1 用于直接进入路由器 PE2 的 ATM 流量,LSP 2 用于在进入路由器 PE2 之前通过路由器 P0 的帧中继流量。

最后,为 ATM 和帧中继第 2 层 电路配置流量分离社区。ATM VC 有社区 gold ,帧中继 VC 有社区 silver。请记住为社区提供数值并配置路由策略以将社区与特定 LSP 匹配。此策略作为策略应用于 export 层次结构级别的转发表 [edit routing-options]

路由器 PE2

content_copy zoom_out_map
[edit]
chassis {
    fpc 1 {
        pic 0 {
            atm-l2circuit-mode {                   
                aal5; # This dedicates FPC 1 PIC 0 to AAL5 mode.
            }
        }
    }
}
interfaces {
    at-1/0/1 {
        description "to CE2 at-1/1/2";
        atm-options {
            pic-type atm2; # Layer 2 circuits are compatible with
            vpi 0; # ATM2 IQ interfaces.
        }
        unit 0 {
            encapsulation atm-ccc-vc-mux; # CLP and EFCI appear in the control word.
            vci 0.32;
        }
    }
    so-0/1/1 {
        description "to P0 so-1/1/2";
        unit 0 {
            family inet {
                address 192.168.27.25/30;
            }
            family mpls; # Include the MPLS family on core-facing interfaces.
        }
    }
    so-1/0/1 {
        description "to PE1 so-1/1/0";
        unit 0 {
            family inet {
                address 192.168.27.9/30;
            }
            family mpls; # Include the MPLS family on core-facing interfaces.
        }
    }
    so-1/1/1 {
        description "to CE4 so-1/1/2";
        dce;
        encapsulation frame-relay-ccc;
        unit 0 {
            encapsulation frame-relay-ccc;
            point-to-point;
            dlci 512;
            family ccc {
                translate-fecn-and-becn; # Option to map FECN/BECN bits to control word.
                translate-discard-eligible; # Option to map DE bit to control word.
            }
        }
    }
    lo0 {
        unit 0 {
            family inet {
                address 10.255.17.4/32;
            }
        }
    }
}
routing-options {
    forwarding-table {
        export layer2communities; # This maps communities to the Layer 2 circuits.
    }
}
protocols {
    mpls {
        label-switched-path lsp1 { # ATM LSP 1 goes directly to Router PE2.
            to 10.255.17.2;
            primary direct;
        }
        label-switched-path lsp2 { # Frame Relay LSP 2 goes through Router P0.
            to 10.255.17.2;
            primary thruP0;
        }
        path direct {
            192.168.27.10 strict;
        }
        path thruP0 {
            192.168.27.26 strict;
            192.168.27.17 strict;
        }
        interface so-0/1/1.0;
        interface so-1/0/1.0;
    }
    ospf {
        traffic-engineering;
        area 0.0.0.0 {
            interface so-0/1/1.0;
            interface so-1/0/1.0;
            interface lo0.0;
        }
    }
    ldp { # LDP is required as the signaling protocol for Layer 2 circuits.
        interface so-0/1/1.0;
        interface so-1/0/1.0;
        interface lo0.0;
    }
    l2circuit {
        neighbor 10.255.17.2 {# This points to the loopback of the PE neighbor.
            interface at-1/0/1.32 { # Here you include the local CE-facing interface.
                virtual-circuit-id 1; # Be sure this ID matches the ID of your PE neighbor.
                community gold;# Assigns the ATM Layer 2 circuit to the gold community.
            }
        }
        neighbor 10.255.17.2 {# This points to the loopback of the PE neighbor.
            interface so-1/1/1.512 { # Here you include the local CE-facing interface.
                virtual-circuit-id 2; # Be sure this ID matches the ID of your PE neighbor.
                community silver; # Assigns the Frame Relay Layer 2 circuit to silver.
            }
        }
    }
}
policy-options {
    policy-statement layer2communities { # Here you map communities to LSPs.
        term 10 {
            from community gold; # Apply community gold to LSP 1.
            then {
                install-nexthop lsp lsp1; 
                accept;
            }
        }
        term 20 {
            from community silver; # Apply community silver to LSP 2.
            then {
                install-nexthop lsp lsp2; 
                accept;
            }
        }
    }
    community gold members 103:1; # Assign numerical value to community gold.
    community silver members 103:2; # Assign numerical value to community silver.
}

在路由器 CE2 上,配置 ATM2 IQ 接口以处理 ATM 流量。接口 at-1/0/1 处理 AAL5 流量。

路由器 CE2

content_copy zoom_out_map
[edit]
interfaces {
    at-1/1/2 {
        description "to PE2 at-1/0/1";
        atm-options {
                               pic-type atm2; # Layer 2 circuits are compatible with
            vpi 0; # ATM2 IQ interfaces.
        }
        unit 0 {
                               encapsulation atm-vc-mux; # Use ATM VC MUX encapsulation on the CE.
                               point-to-point;
            vci 0.32;
            family inet {
                address 10.0.0.2/30;
            }
        }
    }
}

在路由器 CE4 上,配置 SONET/SDH 接口 so-1/1/2 以处理帧中继流量:

路由器 CE3

content_copy zoom_out_map
[edit]
interfaces {
    so-1/1/2 {
        description “ to PE2 so-1/1/1”;
                         encapsulation frame-relay-ccc; # Use Frame Relay encapsulation on the CE.
        unit 0 {
            encapsulation frame-relay-ccc;
            point-to-point;
            dlci 512;
            family inet {
                address 10.10.0.2/30;
            }
        }
    }
}

验证您的工作

要验证流量工程第 2 层 电路的正常运行,请使用以下命令:

content_copy zoom_out_map
show route table mpls.0 detail

在路由器 PE1 上,您可以看到 ATM 流量是值为 103:1 LSP 1 并与 LSP 1 关联的社区的一部分gold。同样,帧中继流量是社区的一部分silver,其值103:2为 LSP 2 并与 LSP 2 相关联:

content_copy zoom_out_map
user@PE1> show route table mpls.0 detail         
mpls.0: 2 destinations, 2 routes (2 active, 0 holddown, 0 hidden)
at-1/1/0.32  (1 entry, 1 announced)
          *L2CKT  Preference: 7
                  Next hop: 192.168.27.9 via so-1/1/0.0 weight 1, selected
                 Label-switched-path lsp1
                 Label operation: Push 100032 Offset: -4
                 Next hop: via so-0/0/1.0 weight 1
                 Label-switched-path lsp2
                 Label operation: Push 100032 Offset: -4
                 Protocol next hop: 10.255.17.4
                 Push 100032 Offset: -4
                  Indirect next hop: 8576bd0 300
                 State: <Active Int>
                 Age: 7:18
                 Task: Common L2 VC
                 Announcement bits (2): 0-KRT 1-Common L2 VC
                 AS path: I
                 Communities: 103:1 # This is the  gold  community.

so-1/1/1.512 (1 entry, 1 announced)
         *L2CKT  Preference: 7
                 Next hop: 192.168.27.9 via so-1/1/0.0 weight 1
                 Label-switched-path lsp1
                 Label operation: Push 100048 Offset: -4
                 Next hop: via so-0/0/1.0 weight 1, selected
                 Label-switched-path lsp2
                 Label operation: Push 100048 Offset: -4
                 Protocol next hop: 10.255.17.4
                 Push 100048 Offset: -4
                  Indirect next hop: 860f1f8 293
                 State: <Active Int>
                 Age: 5:15
                 Task: Common L2 VC
                 Announcement bits (2): 0-KRT 1-Common L2 VC
                 AS path: I
                 Communities: 103:2 # This is the  silver  community.
external-footer-nav