THAI CPE

• Display and examine the current MDA configuration using the show mda command.
  
  *A:vRR# show mda
  
  ===============================================================================
  MDA Summary
  ===============================================================================
  Slot  Mda   Provisioned Type                            Admin     Operational
                  Equipped Type (if different)            State     State
  -------------------------------------------------------------------------------
  1     1     (not provisioned)                           up        unprovisioned
                  m5-1gb-sfp-b
  ===============================================================================
  *A:vRR#
  
  
• Cannot see any MDAs for IOMs that are not configured. Unless an IOM has been configured, it is not possible to get any information about the MDAs that it contains.
  
  
• In the example, the IOM only has a single MDA plugged into it. At most, two MDAs can fit into an IOM.
  
  
• The MDA is plugged into the IOM in Slot 1. This is determined by the value in the Slot column in the command output. The MDA is plugged into the first of the two available MDA slots on the IOM. This is determined by the value in the Mda column in the command output.
  
  
• Generally, an MDA will always be configured to be the same as shown in the Equipped Type column. Configure the available MDA(s). Note that the exact command will depend on the physical hardware; follow the rule of configuring the type to be the same as shown in the show command.
  *A:vRR# configure card 1 mda 1 mda-type m5-1gb-sfp-b
  *A:vRR#
  
  
• In the command configure card 1 mda 1, the parameter card 1 identifies the IOM in Slot 1; the parameter mda 1 identifies the first of the two available MDA slots on the IOM card.
  
  
• Display and examine all MDAs that are now visible.
  *A:vRR# show mda
  
  ===============================================================================
  MDA Summary
  ===============================================================================
  Slot  Mda   Provisioned Type                            Admin     Operational
                  Equipped Type (if different)            State     State
  -------------------------------------------------------------------------------
  1     1     m5-1gb-sfp-b                                up        up
  ===============================================================================
  *A:vRR#
  
  
• Configuring an MDA only changes the "Operational State" making an MDA available. It does not change the number of physical cards, as seen in" the absence of any changes in the Equipped Type column.
  
  
• Have a look at the main log to see what has been recorded as a result of this configuration change.
  *A:vRR# show log log-id 99
  
  
• 
  
  
• 192.0.2.160 and 192.0.2.191 are not used as host addresses on the IP network 192.0.2.160 with a subnet mask of 255.255.255.224 because they are reserved as the subnet and broadcast addresses for the subnet.
  
  
• 
  
  
• Display and examine the current port configuration with show port command.
  
  
• The first section is all the physical ports for the MDA(s) in IOM 1, as indicated by the section heading "Ports on Slot 1."
  
  
• Ports on an MDA are named using three numeric values, for example, 1/1/5. The first value identifies the IOM, the second value identifies the MDA, and the third value identifies the actual port. The (management) ports on an SF/CPM card are named using two values - for example, A/1. The first value identifies the SF/CPM card, and the second value is always a "1" since there is only a single Ethernet port on each SF/CPM card.
  
  
• By default, ports start in the Down state. This is an important point to remember since IOMs and MDAs automatically go to an Up state as soon as their type is configured.
  
  
• The default MTUs for each type of port: 1514 for 10/100 FastE ports and 9212 for GigE ports.
  
  
• Configure a single port to a functional state using configure port x/x/x no shutdown command.

SR - OS Fundamentals

High Leverage Network (HLN)

What is HLN?

HLN = A platform for innovation

• APPLICATION ENABLEMENT
  CAPTIVATE YOUR CUSTOMERS
  
  • Leverage your assets to create personalized content and conversation experiences
  • Capture the creativity of open innovation
  • Develop new business models, increase ARPU, reduce churn
• UNIVERSAL ACCESS
  REACH MORE CUSTOMERS
  
  • Extend always-on broadband to everyone, everything, everywhere
  • Expand customer base, make high-speed broadband affordable
  • Enable open access, bridge fixed and mobile worlds
• NETWORK EVOLUTION
  LEVERAGE YOUR NETWORK
  
  • Evolve to a scalable, efficient and intelligent service delivery network
  • Leverage technical innovations in IP and optics
  • Enable new service value, manage capacity and scale at low cost
• OPERATIONAL TRANSFORMATION
  TRANSFORM YOUR OPERATIONS
  
  • Unify network, IT and business systems
  • Enhance service agility, reduce costs
  • Reduce OPEX, increase efficiency, enhance quality of experience

Tackle Today's Network Challenges

REALIZING THE POTENTIAL OF A CONNECTED WORLD

• Revenue/subscriber
  Increase revenue:
  
  • Leverage network intelligence
  • Deliver differentiated services
  • Develop new business models
  • Monetize assets
• Cost/subscriber
  Reduce costs:
  
  • Scale bandwidth dynamically
  • Manage capacity effectively
  • Transform operations efficiently
  • Harness technical innovation

IES Routed Connectivity Service Example

• Since the traffic in an IES service communicates using an IP interface for the core routing instance, there is no need for the concept of tunneling traffic to a remote router
  
  • A basic IES does not require the configuration of any SDPs

  configure service ies 1000 customer 1 create
    description "IES training"
    interface "to_CE" create
      address 192.168.100.1/30
      sap 1/2/8 create
      exit
    exit
    no shutdown
  

• Configure the router to use wide metrics and a reference bandwidth so that IS-IS computes link metrics the same way as OSPF.
  configure router isis
    reference-bandwidth 10000000
    level 2 wide-metrics-only
  
  
• Multiple IS-IS areas can be used to improve scalability and convergence time.
  
  
• An L1 adjacency will not form in different areas. They must be L2-capable to form an adjacency with a router in a different area.
  
  
• Configure router to summarise address
  configure router isis summary-address <IP/24> level-2
  
  
• RFC 5130 defines the ability to add an additional attribute to IS-IS routes - the administrative route tag. This can be used to identify certain routes that are to receive some special treatment at another point in the network. This might be for routes that are to be exported to another protocol such as BGP (Border Gateway Protocol) or to control leaking between levels in IS-IS.
  
  
• Bidirectional Forwarding Detection (BFD) offers a light-weight, low-overhead, short-duration detection of failures in the path between two systems.
  configure router isis
    interface <interface_name>
      bfd-enable ipv4
  
  
• 
  
  
• Transport Tunnels and Service Tunnels:
  
  • MPLS or GRE tunnels are used to transmit customer data across the service provider network
  • Multiple service tunnels can be carried within a transport tunnel
  • Multiple transport tunnels can be configured on a single network port
  • Inner service label defines the service tunnel; outer transport label defines the transport tunnel
    
    
• Transport and Service Label Encapsulation:
  MPLS encapsulation of VPN service traffic:
  
  • DLC header - Layer 2 header used to transport the MPLS packet
  • MPLS transport (outer) / tunnel label - The label signalled by the next-hop PE
  • Service (inner) label - The service, or virtual circuit (VC) label that identifies the service the packet belongs to
  • Control word - Optional and primarily used for ATM or Frame Relay services
  • Service packet - The customer data being transported by the service
    
    
• GRE encapsulation of VPN service traffic:
  
  • IP header and the GRE header are used instead of the MPLS transport label
  • A service label is still required to demultiplex the packet to the appropriate service
  • The service provider routers use the GRE header to route the packet across the network
    
    
• MPLS transport tunnel signalling protocols:
  
  • LDP or RSVP-TE are used to set up LSPs
  • Provide a means to set up label-switched paths, also known as LSPs, that can carry many other service tunnels
    
    
• Service tunnel signalling protocols:
  
  • Service labels, or VC labels, are used to encapsulate and identify customer traffic that belongs to a particular service
  • A service label is applied to the customer traffic before the transport label, or LSP label is applied
  • VPLS and VPWS services are signalled using targeted LDP, also known as T-LDP
  • VPRN service is signalled by MP-BGP, based on RFC 4364 (formerly RFC 2547bis)
    
    
• Service Label Signalling:
  
  • An IGP is used to provide IP reachability to the routers
  • LDP or RSVP-TE is used to signal the transport tunnel label. Once LDP/RSVP-TE converges end-to-end, an LSP is created
  • T-LDP or MP-BGP is used for service signalling. This provides the inner/service label
    
    
  • The exchange of service labels occurs when the pseudowire is created
  • The following outlines the service label signalling process:
    
    1. PE2 sends PE1 a service label (11350)
    2. PE1 sends PE2 a service label (21350)
    3. Unidirectional service tunnels are created
    4. PE1 uses the label (11350) to send traffic towards PE2
    5. Likewise, PE2 uses label (21350) to send traffic towards PE1
       
       
• Distributed Service:
  
  • A distributed service has components on multiple routers and uses the IP/MPLS network to connect the service and deliver data
  • SDP binding is required to signal the service labels and define the transport to the remote router
    
    
• Binding an SDP to a Service:
  
  • SDPs provide the binding between the control plane signalling of service labels and the transport tunnels (LDP/RSVP or GRE)
  • To direct a service to use an SDP for distribution, the service is joined to the SDP using SDP binding
  • A service label is not signalled unless the service is bound to an SDP
  • Because all service distribution relies on the SDP, the transport is most often RSVP with fast rerouting capabilities
    
    
• Distributed Service Configuration:
  The following steps must be completed for a successful distributed service operation:
  
  • IGP configuration - ensure that routing tables have system addresses
  • Signalling transport labels are enabled for either LDP or RSVP
    
    • LDP has to be enabled for dynamic signalling of service labels using T-LDP
  • Creation of a path - if using RSVP
  • Creation of LSP and bind path - if using RSVP
  • Creation and binding of SDP to LSP - if using RSVP or select LDP
    
    
• Service Verification:
  
  • Once the service is configured on the remote router with a matching VC ID, a service label is signalled and the service is up:
    PE# show service id 50 base
    Provides a summary status of all services
    
  • A service label is signalled and the CE routers can connect to each other through the epipe:
    PE# show router ldp binding fec-type services
    CE# ping 192.168.2.2 size 1472 do-not-fragment count 2
    
    
• An example of SDP Path and Network Port MTU:
  
  • For a gigabit Ethernet network port with an MTU of 9212 (default on the 7750 SR)
  • If SDP uses MPLS encapsulation:
    
    • SDP path MTU = 9212 (network port MTU) - 14 (Ethernet header) - 8 (two MPLS labels) = 9190 bytes
  • If SDP uses GRE encapsulation:
    
    • SDP path MTU = 9212 (network port MTU) - 14 (Ethernet header) - 4 (GRE header) - 20 (IP header) - 4 (service label) = 9170 bytes
      
      
• VPLS vs. Epipe/VPWS:
  Similarities:
  
  • Encapsulation and transport mechanism
  • The signalling of transport and service labels
  • They both use SAPs as the demarcation point between the customer and the provider
    
  • They both support SAP encapsulations of null, dot1Q and Q-in-Q
  • The treatment of customer data at the SAP
    
  Differences/distinguishes:
  
  • A VPLS supports multipoint-to-multipoint connections; epipe is a point-to-point service
  • The VPLS appears as a single switched LAN to the customer; the epipe appears as a direct Ethernet connection
  • A VPLS performs MAC learning to build a forwarding database (FDB) containing the addresses of customer-attached devices, but not by E-pipes
    
    
• VPLS Label Signalling:
  
  • All PE routers in the VPLS are T-LDP peers and exchange labels for the service
  • The VC-ID configured for the service must match among targeted LDP peers
  • Customer frames are encapsulated with a service label and a transport label
  • The VPLS instance on each PE router is often referred to as a virtual switch (VS)
    
    
• Verify the Mesh SDPs:
  
  • The mesh SDPs are operationally up
  • An ingress and an egress service label have been signalled

  PE# show service id 1000 sdp

• Verify Path MTU Using RSVP ADSPEC:
  
  • If ADSPEC is configured on the LSP used as the transport for the SDP, the SDP path-MTU is derived from the path MTU signalled in RSVP using the ADSPEC object
  • Negotiated MTU for the LSP is set to the smallest MTU value found on the path
  • configure router mpls
      lsp "to-PE2"
        to 10.10.10.2
        adspec
        primary "loose"
        exit
        no shutdown
  • show router mpls lsp "to-PE2" path detail
  • The SDP path MTU:
    show service sdp 2
  • The service will down if the SDP path-MTU less than the service MTU
    show service id 50 sdp 2:50 detail
    
    
• Verification:
  
  • The command show service id 50 all displays detailed information related to all aspects of the service
    
    
• SDP and VC Type:
  
  • RFC 4448 defines two VC types for the Ethernet pseudowire
  • The VC type is specified when the SDP is bound to the service and is signalled by T-LDP
    
    • Ether - specifies raw mode (default)
      
      • The service delimiting VLAN tag is stripped at the ingress and is not carried across the epipe
    • VLAN - specifies tagged mode
      
      • A VLAN tags is carried in the frame
        
        
• VC Type Configuration:
  
  • The epipe which is configured with type VLAN:
    configure service epipe 50
      service-mtu 9000
      sap 1/1/4:50 create
      exit
      spoke-sdp 2:50 vc-type vlan create
        vlan-vc-tag 150
      exit
      no shutdown
    
  • The epipe which is using type Ether:
    configure service epipe 50
      service-mtu 9000
      sap 1/1/4:50 create
      exit
      spoke-sdp 1:50 create
      exit
      no shutdown
  • T-LDP will not make a pseudowire operational unless the VC ID and VC type match
    show service service-using epipe
  • Change type Ether to VLAN:
    configure service epipe 50
      spoke-sdp 1:50 shutdown
      spoke-sdp 1:50 vc-type vlan create
        vlan-vc-tag 150
        no shutdown
        exit
    
    
• Fpipe Common Configuration Tasks:
  
  • The fpipe uses the same provisioning steps as an epipe, with the following exceptions:
    
    • The service type is fpipe
    • The physical port or channel is a SONET port set for Frame Relay framing
    • SAP is in the form of port:DLCI (example - 1/1/1:65)
      
      
• The Interworking VPWS capabilities are:
  
  • ATM:
    
    • ATM: Apipe
    • Frame Relay: Apipe (FRF.5 interworking)
    • Ethernet: Epipe (bridged) / Ipipe (routed)
  • Frame Relay:
    
    • Frame Relay: Fpipe
    • Ethernet: Epipe (bridged) / Ipipe (routed)
  • Ethernet:
    
    • Ethernet: Epipe
      
      
• An ethernet VPN service, such as an epipe service, has a default service MTU of 1514 bytes
  
  
• Spoke SDP Termination on VPWS:
  
  • Connect a spoke SDP of a VPLS service (mesh-sdp) with an epipe service (spoke-sdp)
  • The VC-ID of the spoke SDPs on the epipe service and the VPLS service must match
  • VC-ID does not have to match the service ID of either the epipe or the VPLS
  • The service MTU of the VPLS and epipe service must match
  • Configuration:
    configure service vpls 1000
      stp
        shutdown
      exit
      sap 1/1/4 create
      exit
      spoke-sdp 1:100 create
      exit
      mesh-sdp 3:1000 create
      exit
      mesh-sdp 4:1000 create
      exit
      no shutdown
    
    
• The example of svc-ping:
  oam svc-ping 10.10.10.4 service 100 local-sdp
  oam svc-ping10.10.10.4 service 100 local-sdp remote-sdp
  
  • The svc-ping output shows the service MTU as the configured value for the epipe
    
    
• The example of Local Mirror Configuration:
  
  • The mirror destination is configured on SAP 1/1/2
  • The mirror source is configured on SAP 1/1/4 of the epipe to mirror both ingress and egress traffic

  configure mirror mirror-dest 99
    sap 1/1/2 create
    exit
    no shutdown
  
  debug mirror-source 99
    sap 1/1/4 ingress egress
    no shutdown
    exit

• Create a sniffer using IP filter on an epipe SAP configuration:
  
  • Define the filter:
    Sniffer> configure filter
      log 111 create
        destination memory 100
      exit
      ip-filter 11 create
        entry 10 create
          match
            dst-ip 192.168.1.0/27
          exit
          log 111
          action forward
        exit
      exit
  • Applying the filter
    configure service epipe
      sap 1/1/1 create
      exit
      sap 1/1/2 create
        ingress
          filter ip 11
        exit
      exit
      no shutdown
  • configure service epipe show filter log 111
    
    
• Layer 3 Service Spoke SDP Termination Overview:
  
  • Introduces the ability to connect the spoke SDP of a Layer 2 service with a Layer 3 service
  • The spoke is tied to a Layer 2 Service (VPLS or epipe)
  • A Layer 3 (IES or VPRN) IP interface terminates the spoke SDP
    
    
• Spoke SDP Termination: MTU Considerations:
  
  • By default, epipe and VPLS services are configured with a service MTU of 1514. By default, the signalled VC-MTU is 1500.
  • IES and VPRN services have no service MTU configured. By default, there is also no SDP path MTU configured.
    
    
• 3 Epipe services and 2 VPLS services have been configured between two PE routers. 10 service labels will be signalled in total.
  
  
• The following types of service are offered:
  
  • VPN services
    
    • Virtual private wire service (VPWS) - provides a point-to-point service that emulates a leased line
    • Virtual private LAN service (VPLS) - provides a multipoint Ethernet service similar to an Ethernet switch
    • Virtual private routed network service (VPRN) - provides a multipoint IP routed service
  • Internet Enhanced Service (IES)
    
    • Provides the customer with a Layer 3 IP interface to send and receive Internet traffic
  • Mirroring services
    
    
• Virtual Private LAN Service (VPLS):
  
  • VPLS is an Ethernet service that connects multiple sites in a single switched domain over a provider-managed IP/MPLS network
    

• VPRN data plane:
  
  • A data packet arrives at the ingress PE and is encapsulated with both the outer/transport label, learned through LDP, as well as the service label, learned through T-LDP or MP-BGP
  • As the data packet traverses the P routers, the outer label is swapped while the inner label remains unchanged
  • Upon receiving the data packet, the receiving/egress PE removes the outer LDP label. Then, prior to removing the inner label, the receiving PE maps it to the appropriate service
  • The result is the original data packet, which is then forwarded to correct interface for the service, and then on to the CE
    
    
• The two PEs are providing 6VPE and IPv4 VPRNs. The core network is IPv4/MPLS. family vpn-ipv4 vpn-ipv6 is the BGP family configuration for the MP-BGP on the PEs
  
  
• Traffic is flooded to all SAPs, spoke SDPs, and mesh SDPs in the service describes the flooding of traffic on a PE when traffic is received on a spoke SDP
  
  
• FRF.5 is a standard that describes Frame Relay tunnelling over an ATM core network
  
  
• VPRN Architecture:
  
  • Label Stack:
    
    • A VPRN service uses a label stack consisting of two labels
      Layer 2 | LSP Label | VPN Label | IP Data
    • The outer label is known as the top, transport or LSP label and identifies the transport tunnel between PEs
      Allows traffic to transit across the MPLS network
      
    • The inner label is known as the service or VPN label and identifies the customer VPRN service
      MP-BGP is used to signal
      
  • Only the IP packet that is encapsulated for transmission across the VPRN
    
    
• A Cpipe supports both structured and unstructured frames
  
  
• Maximum Transmission Unit (MTU):
  
  • MTU is an important issue in both Layer 2 and Layer 3 services
  • For an IP/MPLS network, the following MTU entities must be considered:
    
    • Access port, or SAP MTU
    • Service and VC MTU
    • SDP path MTU
    • Network port MTU
  • Oversized frames arriving at a Layer 2 interface are not fragmented
  • Layer 3 services will fragment oversized packets for transmission
    
    
• sap 1/1/1:4.* defines a SAP that will select frames with an outer tag of '4' and ignore any inner tag on a Q-in-Q encapsulated port
  
  
• OAM tools are useful in managing and troubleshooting a network
  
  • MPLS paths diagnostic tools:
    
    • lsp-ping and lsp-trace
  • SDP diagnostic tools:
    
    • sdp-ping and sdp-mtu
  • Service diagnostic tools:
    
    • svc-ping
      
      
• SVC-ping or Service ping:
  
  • Verify the round-trip/end-to-end connectivity and delay to the far-end of the service and test the SDPs of a service in both directions
  • Verify the correct and consistent provisioning of a service between two service end points
    
  
  
• Service Distribution Point (SDP) Characteristics:
  
  • A service distribution point (SDP) is a logical entity used to direct traffic for a service from one router to another through a unidirectional service tunnel
  • SDPs are locally unique; the same SDP ID can be used on another router
  • SDPs use the system IP address to identify far-end destination
  • An SDP is not specific to one service; many services can use the same SDP
  • All services bound to the same SDP will have the same transport encapsulation
  • Any operations on an SDP will affect all services that are bound to that SDP
    
    
• Configuring the physical port in access mode and Enabling the port using the no shutdown command need to be configured before a SAP appears
  
  
• Set the ip-mtu of the IES to match the service MTU of the VPLS is the recommended approach for making sure that MTUs between a VPLS and its spoke IES termination match
  
  
• Topology:
  CE1 - PE1 - P1 - P2 - PE2 - CE2 - 192.168.20.1
  A: CE1# traceroute 192.168.20.1
  traceroute to 192.168.20.1, 30 hops max, 40 byte pakets
    <output omitted>
  PE1 and PE2 are providing a VPRN for the CEs. The traceroute run on CE1 will only show 3 hops: CE1-PE1, PE1-PE2 and PE2-CE2
  
  A routing policy is not required on PE1 to advertise a CE1's system interface to PE2; the default behaviour on the 7750 SR is to advertise all VPRN routes between PE routers
  
  
• IES Spoke SDP Termination to a VPLS - IP MTU:
  The MTU values can be made to match by:
  
  • Changing the VC-MTU of the IES using the ip-mtu command (preferred method)
    
    • For Layer 3 service: the signalled VC-MTU = configured IP-MTU
      A: PE-1# configure service ies 100 interface "To_VPLS_1000"
        ip-mtu 1500
  • Adjusting the SDP path MTU (not recommended)
  • Adjusting the network port MTU (not recommended)

  Whereas in epipe and VPLS services the signalled VC-MTU = configured service-mtu - 14 (Ethernet header)
  

• If the router is rebooted after an "admin save" has been performed, Only the mirror source must be re-configured
  
  
• A network consists of four PE routers. A customer requires a VPLS and has sites connected to each PE. The VPLS is fully meshed using IP/MPLS. 3 SDPs must be configured on each PE
  
  
• Hierarchical VPLS (H-VPLS):
  
  • Enables VPLS services to span multiple metro networks
  • Creates scalable VPLS. They allow a VPLS to scale more easily. They simplify the configuration required when adding new PEs
    
  • A spoke SDP is used to connect smaller meshed VPLSs together
    
    
• The purpose of an MP-BGP in a VPRN:
  
  • The service provider uses MP-BGP to distribute the routes for the different customer networks
  • In a VPRN service, MP-BGP is used to exchange customer routes across the VPRN
  • Targeted (targeted) LDP/T-LDP or MP-BGP is used to establish/creates an end-to-end connection-oriented session between PEs, and providing/propagates the inner/service label
    
    
• Transport tunnels:
  
  • RSVP-TE or LDP signalled LSP:
    
    • Labels are signalled using RSVP-TE or LDP
    • The MPLS-encapsulated data is forwarded to the egress PE for the service
  • GRE tunnel:
    
    • The data is encapsulated with an IP header
    • The source IP address is the ingress PE router and the destination address is the egress PE router
    • Typically used when there are routers in the transport network that do not support MPLS label switching
      
      
• Service tunnels:
  
  • MP-BGP or T-LDP are used to set up per-VPN service tunnels
    
    
• Multiprotocol BGP (MP-BGP):
  
  • Multiprotocol BGP (MP-BGP) extensions allow VPN-IPv4 prefixes to distribute VPRN routing information across the service provider's network
  • The VPN-IPv4 address family is only used in the provider core control plane when exchanging MP-BGP routing updates
    
    
• Virtual Private Routed Network (VPRN):
  
  • VPRN is an IP (Layer 3) service that connects multiple sites in a single routed domain over the provider-managed IP/MPLS network
    

• Complete the VPRN service configuration on PE for Customer Blue:
  A: PE# configure service vprn 10 customer 10 create
    description "Customer Blue"
    router-id 10.10.10.1
    autonomous-system 64496
    route-distinguisher 64496:1
    auto-bind ldp
    vrf-target target:64496:10
    interface "toR3" create
      address 10.1.3.1/27
      sap 1/1/3 create
      exit
    exit
    bgp
      group "toCE1"
        neighbor 10.1.3.3
          export "mbgp-bgp"
          peer-as 64497
        exit
      exit
    exit
    no shutdown
  
  
• MP-BGP protocol is used to signal the service label for a Layer 3 VPRN service
  
  
• A service:
  
  • Provides connectivity between customer access points
  • A logical entity that provides a uniform, end-to-end configuration, management and billing model for provisioning either the Internet or VPN connectivity
  • A service that can either be local or distributed
    
    
• adspec command is used in an RSVP signalled MPLS tunnel to validate the path MTU based on signalling across the LSP
  
  
• Conditions are necessary in order for service labels to be signalled between two PE routers:
  
  • LDP must be enabled on both PE routers
  • The transport tunnel must be operationally up between the two PE routers in both directions
  • The VC-ID must match between the two PE routers in both directions
    
    
• # show service id 333 base command can indicate that an SDP is up or down
  # show router ldp bindings service-id 333 command
  
  • Can show the service MTU on peer has been set to a different value or not
  • Can be used to compare the VC MTU signalled between two PE routers
  • RMTU = 0 means peer has not sent a label to this router yet
    
  
  
• An IES must have at least one SAP defined
  
  
• In a Layer 2 encapsulation, using Martini, the first (top) label represent Tunnel Label
  
  
• Configuring an SDP between an IES and a VPLS, the SDP must be a spoke and the layer 2 MTUs must match between the IES and the VPLS
  
  
• In a Layer 2 VPN service, the FCS is stripped when a customer packet arrives at the ingress PE and regenerated on egress
  
  
• VPN-IPv4 address family:
  
  • A VPN-IPv4 prefix is composed of a route distinguisher (RD) and an IPv4 address
  • PE routers are responsible for creating VPN-IPv4 prefixes
  • VPN-IPv4 allows multiple customers to have overlapping IP addresses
    
    
• On the spoke SDP in the E-pipe component is vc-type configured to create an E-pipe service that preserves the VLAN tag during transport
  
  
• The OAM command svc-ping can be used with options local-sdp and remote-sdp, local-sdp indicates that the ping is sent in-band, and remote-sdp indicates the return ping is in-band
  
  
• 6 service labels must be signalled to bring up a fully-meshed VPLS among three PE routers (3x(3-1))
  
  
• A route target is:
  
  • Route target attributes are earned in an MP-BGP as attributes of the route
  • Used by the PE router to identify the VRF that a VPN-IPv4 prefix is associated with
  • A mechanism from which VPRN controls the distribution of VPN routing information
  • A BGP extended community used to identify the VRF table for a prefix at the receiving PE
    
    
• Routing information between the CE and PE can be exchanged using the BGP, RIP, OSPF, static routes, and OSPF3 methods
  
  
• SAPs:
  
  • VPWS: SAPs can be defined on Ethernet, POS, SONET/SDH, or TDM channels
  • VPWS: Two SAPs can be defined for a service that originates and terminates on the same router
  • VPLS: More than two SAPs can be defined in a service
    
    
• By default, Maintains a different MAC Forwarding Database for each service does a router do to support VPLS services for different customers
  
  
• Flood the frame to all PEs participating in the service does a PE do when a frame is received in a VPLS service with an unknown destination address by default
  
  
• Routes are exchanged between CE1 and PE1 using BGP. CE2 and PE2 use static routes to forward traffic to and from the VPRN:
  
  • An export policy is required on PE1 to advertise routes to CE1
  • An export policy is required on CE1 to advertise local routes to PE1
  • No export policy is required on PE2 or CE2 due to the static routes
    
    
• A customer has sites on three different routers. The customer requires a fully-meshed VPLS. Each router requires 2 SDPs
  
  
• When configuring distributed services across a network, it is considered best practice to configure Customer ID and Service ID parameters as globally significant
  
  
• The keys benefit of a VPLS service:
  
  • The customer maintains complete control over routing
  • The clear demarcation of functionality between service provider and customer makes troubleshooting easier
  • The adding of new sites is simplified; no re-configuration is required at existing sites
    
    
• Dot1Q SAPs:
  
  • The dot1Q default SAP (port:*) accepts all untagged frames and any frames with tag values that are not used as a service-delimiting value on another SAP
  • A dot1q null SAP (port:0) and a dot1q default SAP (port:*) cannot both be defined on the same port
  • The dot1Q default SAP (port:*) can be used to pass VLAN tags transparently through a network
    
    
• Customers can connect to the same service using different subnets is a benefit of VPRN as compared to VPLS
  
  
• A SAP configured in the form of 1/1/1:0/32 would be used for A-pipe type of VPWS
  
  
• 20 service labels must be signalled to bring up a fully-meshed VPLS among five PE routers
  
  
• A separate FDB is maintained for each VPLS service to track MAC addresses learned from each service
  
  
• An IES interface has an IP address assigned to it and IES has a configurable IP-MTU are the two major differences between configuring an IES service and configuring VPWS or VPLS services
  
  
• Example of IES Configuration:
  
  A: PE-1# configure service ies 100
    interface "to-Site1" create
      address 192.168.100.2/27
      sap 1/1/4:1 create
      exit
    exit
    interface "to-Site2" create
      address 192.168.200.2/27
      sap 1/1/4:2 create
      exit
    exit
    no shutdown
  
  A: CE1# configure router
    interface "IES_1"
      address 192.168.100.1/27
      port 1/1/3:1
    exit
    interface "IES_2"
      address 192.168.200.1/27
      port 1/1/3:2
    exit
  
  
• A fully meshed VPLS service with a default setting:
  
  • The signalling on all PE routers will default to TLDP in the configuration of the SDPs; therefore, no configuration change is required for dynamic signalling
  • The vc-id on the mesh-sdp must be explicitly configured
  • The VPLS service id, on all PE routers, must match
    
    
• Ingress label, MAC filter, and IP filter can be used as a mirror source, Egress label CANNOT

• Properly configure a single/multiple-area OSPF instance:
  
  • Enable the OSPF context
  • Create an area/many areas as needed
    
  • Add to this/each area the system and the physical interfaces on which OSPF is to be spoken
  • Select the proper interface type (point-to-point or broadcast)
  • Specify the type needed for each area
    
  
  
• configure router ospf area <area-id>
  configure router ospf area <area-id> interface <interface-name> [interface-type <type>]
  configure router ospf area 0 interface toR2 interface-type point-to-point
  configure router policy-options
    begin
    prefix-list loopback
      prefix-list 4.4.4.4/32 exact
    exit
    policy-statement from-direct-to-ospf
      entry 10
        from
          protocol direct
          prefix-list loopback
        exit
        to
          protocol ospf
        exit
        action accept
        exit
      exit
    exit
    commit
  configure router ospf export <policy-name>
  configure router ospf export from-direct-to-ospf
  configure router ospf asbr
  configure router ospf [no] shutdown
  show router ospf status: provides information as to whether the protocol is operational
  show router ospf <instance-number> interface : lists the interfaces that are running OSPF and whether they are operational; it also displays the area that the interface belongs to
  show router ospf <instance-number> neighbors : displays a list of neighbours that have been discovered and the status of the adjacency that is being formed with each of them; it also displays the area that the adjacency belongs to
  show router ospf <instance-number> database : displays the list of LSAs (Link State Advertisements) that have been exchanged with adjacent neighbours; it also displays the area that each LSA belongs to
  show router ospf routes : displays the list of IP sub-networks that have been discovered as well as the calculated next hop for each one of them
  
  
• Loop Free Alternate (LFA) or IP Fast ReRoute:
  The goal is to reduce failure reaction time to 10s of milliseconds by using a pre-computed alternate next-hop, in the event that the currently selected primary next-hop fails so that the alternate can be rapidly used when the failure is detected
  
  
• LFA is based on two principles:
  
  • local rerouting
  • pre-computed detours
    
    
• LFA paths can only be calculated when the router works in chassis mode d, default is a
  show chassis
  configure system chassis-mode d: no service impact
  configure router ospf loopfree-alternate
  show router route-table
    Flags: L = LFA
  show router route-table alternative
  
  
• show router fib <slot-number>
  show router fib 1
  To allow the router to use the alternative paths found, the following command needs to be issued:
  configure router ip-fast-reroute
  
  
• The primary path and the LFA path do not constantly share the traffic load. Only the primary path is active and the LFA path will only become active if the primary one fails. The goal of enabling LFA is resiliency, not load-balancing
  
  
• An OSPF ASBR does not need interface in the backbone area 0.0.0.0
  
  
• configure router ospf area <area-id> stub
  configure router ospf area <area-id> stub no summaries
  configure router ospf area <area-id> nssa
  configure router ospf area <area-id> nssa originate-default-route
  
  
• Features are supported by IS-IS:
  
  • The ability to customize the link cost metric
  • PDU authentication
  • Classless routing
    
    
• IS-IS packet types:
  
  • Hello: discover neighbouring routers, assess if they are compatible to establish an adjacency, elect the DIS on broadcast links, As keep-alive after an adjacency has been formed
  • Partial Sequence Number PDU - PSNP describes contents of the local LSDB in a condensed manner, partial list of the LSPs included in LSDB
  • Complete Sequence Number PDU - CSNP describes contents of the local LSDB in a condensed manner complete list of the LSPs included LSDB
  • Link-State PDU - LSP share topology & IPv6 reachability info to calculate the shortest path to any sub-network
    
    
• IS-IS adjacency states:
  
  
  • Down:
    
    • If neighbour has not been discovered

  • INIT:
    

    • one-way communication has been verified via Hello messages
    • If adjacency is stuck either Down or INIT state, some parameters are not compatible (area for L1, authentication, interface types - point-to-point vs. broadcast)
      
  • UP:
    
    • two-way communication has been verified via Hello messages
    • If adjacency is UP, but routing info is not shared, authentication for Hello messages is properly configured, but authentication for other types of messages is misconfigured
      
    
    
• Properly configure a single-area/multiple areas IS-IS instance:
  
  • Enable the IS-IS context
  • Associate the router to the proper area
  • Add to the IS-IS context the system and the physical interfaces on which IS-IS is to be spoken (remember that in IS-IS it is the router which belongs to one area or another, not the interfaces)
    
  • Select the proper interface type (point-to-point or broadcast)
  • Make sure that routers at the border between two areas are L1/L2 capable and that there is a continuous backbone of L1/L2-capable routers in the network
    
  
  
• configure router isis area-id <area-id>
  configure router isis area-id 49.00
  configure router isis interface <interface-name> [interface-type <type>]
  configure router isis interface system
  configure router isis interface toR2 interface-type point-to-point
  configure router isis export <policy-name>
  configure router isis [no] shutdown
  show router isis <instance-number> status : provides information as to whether the protocol is operational
  show router isis <instance-number> interface : lists the interfaces that are running IS-IS and whether they are operational; it also displays if the interface is L1- or L2-capable (or both)
  show router isis <instance-number> adjacency : displays a list of neighbours that have been discovered and the status of the adjacency that is being formed with each of them; it also displays the level that the adjacency belongs to (L1, L2 or both)
  show router isis <instance-number> database : displays the list of LSPs (Link State PDUs) that have been exchanged with adjacent neighbours; it also displays the level that the LSP belongs to (L1 or L2)
  show router isis <instance-number> routes : displays the list of IP sub-networks that have been discovered as well as the calculated next hop for each one of them
  
  
• configure router isis loopfree-alternate
  required: configure router ip-fast-reroute
  

• PE# configure service sdp 2
    far-end 10.10.10.2
    lsp "to-PE2"
    keep-alive
      shutdown
    exit
    no shutdown
  # show service sdp
  
  
• Changing the SAP & Network Port MTU:
  configure port 1/1/4 shutdown
  configure port 1/1/4 ethernet mtu 1522
  configure port 1/1/4 no shutdown
  
  show service sap-using
  
  
• L3VPN Configuration with BGP PE-CE routing:
  
  /configure service customer 2100 create
              description "Customer"
  
  /configure qos
      scheduler-policy "Limit3M-L3" create
          description "Limit3M-L3"
          tier 3
              scheduler "root" create
                  rate 3225 cir 3225
              exit
          exit
      scheduler-policy "Shape3M-L3" create
          description "Shape3M-L3"
          tier 3
              scheduler "root" create
                  rate 3225 cir 3225
              exit
          exit
  
  /configure router policy-options
      begin
      prefix-list "to_Customer"
          prefix x.x.x.x/x exact
      exit
  
      policy-statement "Export_BGP"
          entry 10
              from
                  protocol bgp-vpn
                  prefix-list "to_Customer"
              exit
              action accept
              exit
          exit
      exit
  
      prefix-list "from_Customer"
          prefix y.y.y.y/y exact
      exit
  
      policy-statement "Import_BGP"
          entry 10
              from
                  protocol bgp
                  prefix-list "from_Customer"
              exit
              action accept
              exit
          exit
      exit
      commit
  
  /configure service vprn 71010348 customer 2100 create
      interface Intf.2137 create
          description "Customer1"
          address z.z.z.z/30
          remote-proxy-arp
          sap lag-90:2137.0 create
              ingress
                  scheduler-policy "Limit3M-L3"
                  qos 11
              exit
              egress
                  scheduler-policy "Shape3M-L3"
                  qos 11
              exit
          exit
          no shutdown
      exit
  
      bgp
          min-route-advertisement 1
          router-id z.z.z.z
          rapid-withdrawal
          group "to-Customer1"
              import "Import_BGP"
              export "Export_BGP"
              neighbor z.z.z.a
                  peer-as bb
              exit
          exit
          no shutdown
      exit
      no shutdown
   exit
  
  
• The primary objective for SR (Segment Routing) is source routing what is the ability for a node to specify a unicast forwarding path, other than the normal shortest path, that a particular packet will traverse