Protocol Configurations

This validated solution design topology uses OSPFv2/v3 as the interior gateway protocols to distribute IP routing information among the routers in an Autonomous System (AS). The Label Distribution Protocol (LDP) is used to exchange label mapping information for MPLS traffic. And, iBGP is used for exchanging routing and reachability information within ASs.

One thus needs to configure the following protocols:

OSPFv2/v3: To ensure IP connectivity on the core network.
LDP: To establish MPLS LSP tunnels for MPLS data transmission on the network.
iBGP: To exchange routing information within an AS.

Configure OSPFv2/v3

The following steps provide the commands to execute various functionalities of the OSPFv2/v3 protocols. For more detailed information about OSPF configuration, see OSPF User Guide.

Configure OSPFv2/v3 address family, hostname, interface, area, segment routing, and instance ID (for IPv6).

set instance default protocol ospf address-family ipv4 hostname C-BNG
set instance default protocol ospf address-family ipv4 segment-routing srgb base 100000
set instance default protocol ospf address-family ipv4 segment-routing srgb range 2000
set instance default protocol ospf address-family ipv4 area 0.0.0.0
set instance default protocol ospf address-family ipv4 area 0.0.0.0 interface ifl-0/1/17/10
set instance default protocol ospf address-family ipv4 area 0.0.0.0 interface ifl-0/1/17/10 network-type p2p
set instance default protocol ospf address-family ipv4 area 0.0.0.0 interface lo-0/0/1/0
set instance default protocol ospf address-family ipv4 area 0.0.0.0 interface lo-0/0/1/0 segment-routing index 100
set instance default protocol ospf address-family ipv6 instance-id 0
set instance default protocol ospf address-family ipv6 instance-id 0 hostname C-BNG
set instance default protocol ospf address-family ipv6 instance-id 0 segment-routing srgb base 200000
set instance default protocol ospf address-family ipv6 instance-id 0 segment-routing srgb range 2000
set instance default protocol ospf address-family ipv6 instance-id 0 area 0.0.0.0
set instance default protocol ospf address-family ipv6 instance-id 0 area 0.0.0.0 interface ifl-0/1/17/10
set instance default protocol ospf address-family ipv6 instance-id 0 area 0.0.0.0 interface ifl-0/1/17/10 network-type p2p
set instance default protocol ospf address-family ipv6 instance-id 0 area 0.0.0.0 interface lo-0/0/1/0
set instance default protocol ospf address-family ipv6 instance-id 0 area 0.0.0.0 interface lo-0/0/1/0 segment-routing index 100
commit

OSPFv2/v3 instance configuration on interface is shown below:

supervisor@rtbrick>C-BNG.rtbrick.net: cfg> show config instance default protocol ospf address-family
{
  "rtbrick-config:address-family": {
    "ipv4": {
      "hostname": "C-BNG",
      "segment-routing": {
        "srgb": {
          "base": 100000,
          "range": 2000
        }
      },
      "area": [
        {
          "area-id": "0.0.0.0",
          "interface": [
            {
              "name": "ifl-0/1/17/10",
              "network-type": "p2p"
            },
            {
              "name": "lo-0/0/1/0",
              "segment-routing": {
                "index": 100
              }
            }
          ]
        }
      ]
    },
    "ipv6": {
      "instance-id": [
        {
          "instance-id": 0,
          "hostname": "C-BNG",
          "segment-routing": {
            "srgb": {
              "base": 200000,
              "range": 2000
            }
          },
          "area": [
            {
              "area-id": "0.0.0.0",
              "interface": [
                {
                  "name": "ifl-0/1/17/10",
                  "network-type": "p2p"
                },
                {
                  "name": "lo-0/0/1/0",
                  "segment-routing": {
                    "index": 100
                  }
                }
              ]
            }
          ]
        }
      ]
    }
  }
}

Configure LDP on the Interfaces

The following steps provide the commands to execute various LDP functionalities. For more detailed information about LDP configuration, see LDP User Guide.

Configure LDP on the router interface.

set instance default protocol ldp router-id 192.0.2.64
set instance default protocol ldp interface ifl-0/0/1/10
set instance default protocol ldp interface lo-0/0/1/0
commit

Configuration for LDP on the interface is shown below:

supervisor@rtbrick>C-BNG.rtbrick.net: cfg> show config instance default protocol ldp
{
  "rtbrick-config:ldp": {
    "router-id": "192.0.2.64",
    "interface": [
      {
        "name": "ifl-0/0/1/10"
      },
      {
        "name": "lo-0/0/1/0"
      }
    ]
  }
}

Configure BGP

The following steps provide the commands to execute the various BGP functionalities quickly. For more detailed information about BGP configuration, see BGP User Guide.

Configure BGP local AS, router-id, and hostname

set instance default protocol bgp local-as 4200000001
set instance default protocol bgp router-id 192.0.2.64
commit

BGP local AS, router-id, and hostname configurations are shown below:

supervisor@rtbrick>C-BNG.rtbrick.net: cfg> show config instance default protocol bgp
{
  "rtbrick-config:bgp": {
    "local-as": 4200000001,
    "router-id": "192.0.2.64",

<....>

Enable the IPv4 and IPv6 address families which are to be supported on the specific BGP instance.

set instance default protocol bgp address-family ipv4 unicast
set instance default protocol bgp address-family ipv4 unicast resolve-nexthop safi labeled-unicast
set instance default protocol bgp address-family ipv4 unicast redistribute direct
set instance default protocol bgp address-family ipv6 labeled-unicast
set instance default protocol bgp address-family ipv6 unicast
set instance default protocol bgp address-family ipv6 unicast resolve-nexthop safi labeled-unicast
set instance default protocol bgp address-family ipv6 unicast redistribute direct
commit

BGP address family configuration is shown below:

supervisor@rtbrick>C-BNG.rtbrick.net: cfg> show config instance default protocol bgp address-family
{
  "rtbrick-config:address-family": [
    {
      "afi": "ipv4",
      "safi": "unicast",
      "resolve-nexthop": {
        "safi": "labeled-unicast"
      },
      "redistribute": [
        {
          "source": "direct"
        }
      ]
    },
    {
      "afi": "ipv6",
      "safi": "labeled-unicast"
    },
    {
      "afi": "ipv6",
      "safi": "unicast",
      "resolve-nexthop": {
        "safi": "labeled-unicast"
      },
      "redistribute": [
        {
          "source": "direct"
        }
      ]
    }
  ]
}

Create the peer group with the specific remote AS configurations and the address family that is to be negotiated with the peer which will be attached to the peer group later.

set instance default protocol bgp peer-group RR
set instance default protocol bgp peer-group RR remote-as 4200000001
set instance default protocol bgp peer-group RR address-family ipv4 unicast
set instance default protocol bgp peer-group RR address-family ipv6 labeled-unicast
set instance default protocol bgp peer-group RR address-family ipv6 unicast
set instance default protocol bgp peer-group RR address-family ipv6 unicast send-label true
commit

BGP peer-group configuration is shown below:

supervisor@rtbrick>C-BNG.rtbrick.net: cfg> show config instance default protocol bgp peer-group
{
  "rtbrick-config:peer-group": [
    {
      "pg-name": "RR",
      "remote-as": 4200000001,
      "address-family": [
        {
          "afi": "ipv4",
          "safi": "unicast"
        },
        {
          "afi": "ipv6",
          "safi": "labeled-unicast"
        },
        {
          "afi": "ipv6",
          "safi": "unicast",
          "send-label": "true"
        }
      ]
    }
  ]
}
supervisor@rtbrick>C-BNG.rtbrick.net: cfg>

Add a BGP peer and associate it with the specific peer group.

set instance default protocol bgp peer
set instance default protocol bgp peer ipv4 198.51.100.3 192.0.2.64
set instance default protocol bgp peer ipv4 198.51.100.3 192.0.2.64 peer-group RR
commit

Configuration for adding a BGP peer and associating it with a peer group is shown below:

supervisor@rtbrick>C-BNG.rtbrick.net: cfg> show config instance default protocol bgp peer
{
  "rtbrick-config:peer": {
    "ipv4": [
      {
        "peer-address": "198.51.100.3",
        "update-source": "192.0.2.64",
        "peer-group": "RR"
      }
    ]
  }
}

Configure the IPv6 unicast address family with send-label as true, then address-family IPv6 labeled-unicast gets negotiated with the peer.

set instance default protocol bgp peer-group RR address-family ipv6 unicast send-label true
commit

The following configuration shows the BGP IPv6 unicast address family with send-label as true.

supervisor@rtbrick>C-BNG.rtbrick.net: cfg> show config instance default protocol bgp peer-group RR address-family ipv6 unicast
{
  "rtbrick-config:address-family": [
    {
      "afi": "ipv6",
      "safi": "unicast",
      "send-label": "true"
    }
  ]
}

Set the resolve-nexthop, if the BGP nexthop attribute of the BGP routes needs to be resolved under ipv4/ipv6 labeled-unicast routing table. It configures only resolve-nexthop safi. Based on the nexthop-type (ipv4 or ipv6), it gets looked up into either IPv4 labeled-unicast or IPv6 labeled-unicast.

set instance default protocol bgp address-family ipv4 unicast resolve-nexthop safi labeled-unicast
commit

Resolve nexthop configuration is shown below:

supervisor@rtbrick>C-BNG.rtbrick.net: cfg> show config instance default protocol bgp address-family ipv4 unicast resolve-nexthop
{
  "rtbrick-config:resolve-nexthop": {
    "safi": "labeled-unicast"
  }
}
supervisor@rtbrick>C-BNG.rtbrick.net: cfg>

To redistribute the routes (belonging to a specific source) into BGP, execute the following command. The following command redistributes direct routes into BGP.

set instance default protocol bgp address-family ipv4 unicast redistribute direct
commit

supervisor@rtbrick>C-BNG.rtbrick.net: cfg> show config instance default protocol bgp address-family ipv4 unicast redistribute
{
  "rtbrick-config:redistribute": [
    {
      "source": "direct"
    }
  ]
}
supervisor@rtbrick>C-BNG.rtbrick.net: cfg>

Configuring the Service Node

Configuring Interfaces on the Service Node for RADIUS Connectivity from C-BNG

To configure interfaces on the Service Node for RADIUS connectivity from C-BNG, enter the following commands:

sudo ip link add link SN-2-DT name SN-2-DT.100 type vlan id 100
sudo ifconfig SN-2-DT.100 192.0.2.34/27

SN-2-DT is the internal nomenclature that denotes the interface name on Service Node that connects to the C-BNG.

Configuring Interfaces on the Service Node for NTP and TACACS Connectivity from C-BNG

To configure interfaces on the Service Node for NTP and TACACS connectivity from C-BNG, enter the following commands:

sudo ip link add link SN-2-DT name SN-2-DT.200 type vlan id 200
sudo ifconfig SN-2-DT.200 192.0.2.98/27
sudo ifconfig lo:1 192.0.2.129 netmask 255.255.255.255 up
sudo ifconfig lo:2 192.0.2.130 netmask 255.255.255.255 up

Configuring Routes on the Service Node

To configure routes on the Service Node that provide reachability to the RADIUS, TACACS and NTP servers, enter the following commands:

sudo ip route add 192.0.2.74/32 via 192.0.2.33
sudo ip route add 192.0.2.131/32 via 192.0.2.97
sudo ip route add 192.0.2.128/32 via 192.0.2.97

BNG Blaster Configuration for Protocols

BNG Blaster is an open-source network testing platform for access and routing protocols. It can emulate massive PPPoE and IPoE (DHCP) subscribers including IPTV, and L2TP (LNS). There are various routing protocols supported such as OSPFv2/v3 and BGP. So, one can use this platform for end-to-end BNG and non-BNG router testing.

For more information about BNG Blaster, see https://github.com/rtbrick/bngblaster

For information about installing BNG Blaster, see https://rtbrick.github.io/bngblaster/install.html

Downloading the Blaster Configuration File

The following is the configuration file that is used in BNG Blaster for validating PPPoE, IPoE, BGP, OSPFv2/v3, and LDP.

Click here to download the BNG Blaster configuration file (blaster_cgnat.json).

Generating Supporting Files for Protocols

Generating BGP Internet Prefixes

Enter the following commands to generate BGP internet prefixes.

bgpupdate -f internet.bgp -a 4200000001 -n 198.51.100.2 -N 1 -p 172.16.0.0/24 -P 1000000
bgpupdate -f internet.bgp -a 4200000001 -n 198.51.100.2 -N 1 -p 2004::/48 -m 10000 -M 5 -P 150000 --append

Ensure that the command execution has finished (as shown below) before continuing.

[2023-04-05 10:19:32][INFO   ] init 1000000 IPv4 prefixes
[2023-04-05 10:19:56][INFO   ] open file internet.bgp (replace)
[2023-04-05 10:25:31][INFO   ] finished

After the generation of the internet.bgp file, the "raw-update-file" attribute of the blaster_cgnat.json file needs to be updated as follows:

"raw-update-file": "/home/supervisor/internet.bgp"

For more information about downloading the blaster_cgnat.json file, see section Downloading the Blaster Configuration File.

Generating MRT File for OSPF

The .mrt file, which is used by BNG Blaster, represents the simulated topology of the network that includes R-1 and R-2.

Below are the JSON files (ospfv2_3node.json and ospfv3_3node.json) which are used to simulate R-1, R-2, and RR on BNG Blaster.

Click here to download the ospfv2_3node.json file.

Click here to download the ospfv3_3node.json file.

The ospfv2_3node.json file needs to be converted to MRT format using the following command:

lspgen -r ospfv2_3node.json -m ospf.mrt

The ospfv3_3node.json file needs to be converted to MRT format using the following command:

lspgen -r ospfv3_3node.json -m ospfv3.mrt

After converting the files to ospf.mrt and ospfv3.mrt, it needs to be updated in the OSPF section in the blaster_cgnat.json file as shown below.

"mrt-file": "/home/supervisor/ospfv3.mrt"

"mrt-file": "/home/supervisor/ospfv3.mrt"

Generate labels for the OSPF prefixes using "ldpupdate" command as shown below:

ldpupdate -l 192.0.2.65 -p 198.51.100.1/32 -P 3 -M 3 -f out.ldp

The detail of the generated file needs to be added to the LDP section in the blaster_cgnat.json file as shown below:

"raw-update-file": "/home/supervisor/out.ldp"

Starting BNG Blaster

In the following command line string, a BNG Blaster instance is started and the blaster_cgnat.json file is used.

sudo bngblaster -C blaster_cgnat.json -I

The -C blaster_cgnat.json argument specifies the blaster configuration file. The -I flag enables the interactive blaster UI.

Validating Protocols on RBFS Consolidated BNG

Validating OSPF Adjacency, Routes and Reachability

Run the following command to show OSPF adjacency.

supervisor@rtbrick>C-BNG.rtbrick.net: op> show ospf neighbor
Instance: default, Address family: ipv4
  Address                        Interface            Router          Area            State      Priority  DR
   BDR             Uptime          Expires
  192.0.2.2                      ifl-0/0/1/10      R1              0.0.0.0         Full       64        0.0.0.0         0.0.0.0         0d:00h:00m:03s  38s

After configuring OSPF protocol, check the IPv4 unicast routes, populated by OSPF using the following command:

supervisor@rtbrick>C-BNG.rtbrick.net: op> show route ipv4 unicast source ospf instance default
Instance: default, AFI: ipv4, SAFI: unicast
Prefix/Label                                Source            Pref    Next Hop                                    Interface
192.0.2.65/32                               ospf              10      192.0.2.2                                   ifl-0/0/1/10
198.51.100.1/32                             ospf              10      192.0.2.2                                   ifl-0/0/1/10
198.51.100.2/32                             ospf              10      192.0.2.2                                   ifl-0/0/1/10
198.51.100.3/32                             ospf              10      192.0.2.2                                   ifl-0/0/1/10
198.51.100.100/31                           ospf              10      192.0.2.2                                   ifl-0/0/1/10
198.51.100.102/31                           ospf              10      192.0.2.2                                   ifl-0/0/1/10
198.51.100.104/31                           ospf              10      192.0.2.2                                   ifl-0/0/1/10

Ping the address 192.0.2.65 as follows:

supervisor@rtbrick>C-BNG.rtbrick.net: op> ping 192.0.2.65
68 bytes from 192.0.2.65: icmp_seq=1 ttl=64 time=8.2474 ms
68 bytes from 192.0.2.65: icmp_seq=2 ttl=64 time=1.3832 ms
68 bytes from 192.0.2.65: icmp_seq=3 ttl=64 time=4.2682 ms
68 bytes from 192.0.2.65: icmp_seq=4 ttl=64 time=1.1797 ms
68 bytes from 192.0.2.65: icmp_seq=5 ttl=64 time=1.2778 ms
Statistics: 5 sent, 5 received, 0% packet loss

Validating LDP Adjacency, Routes and Reachability

Run the following commands to show LDP neighbor and LDP session.

supervisor@rtbrick>C-BNG.rtbrick.net: op> show ldp neighbor
Instance: default
  Interface/Peer      LDP ID              Transport IP              Up Since                  Expires
  ifl-0/0/1/10     192.0.2.65:0        192.0.2.65                Thu Mar 21 06:27:38       in 14s

supervisor@rtbrick>C-BNG.rtbrick.net: op> show ldp session
Instance: default
  LDP ID            Peer IP                   State             Up/Down           FECRcvd   FECSent
  192.0.2.65:0      192.0.2.65                Operational       0d:00h:02m:56s          5         5

After configuring the LDP protocol, check the IPv4 labeled unicast routes, populated by LDP using the following command:

supervisor@rtbrick>C-BNG.rtbrick.net: op> show  route ipv4 labeled-unicast source ldp
Instance: default, AFI: ipv4, SAFI: labeled-unicast
Prefix/Label                                Source            Pref    Next Hop                                    Interface                      Label
192.0.2.65/32                               ldp               9       192.0.2.2                                   ifl-0/0/1/10                -
198.51.100.1/32                             ldp               9       192.0.2.2                                   ifl-0/0/1/10                10000
198.51.100.2/32                             ldp               9       192.0.2.2                                   ifl-0/0/1/10                10001
198.51.100.3/32                             ldp               9       192.0.2.2                                   ifl-0/0/1/10                10002

Ping the labeled unicast address 198.51.100.1 as follows:

supervisor@rtbrick>C-BNG.rtbrick.net: op> ping 198.51.100.1 instance default afi ipv4 safi labeled-unicas
t
68 bytes from 198.51.100.1: icmp_seq=1 ttl=64 time=.2344 ms
68 bytes from 198.51.100.1: icmp_seq=2 ttl=64 time=4.1493 ms
68 bytes from 198.51.100.1: icmp_seq=3 ttl=64 time=6.9031 ms
68 bytes from 198.51.100.1: icmp_seq=4 ttl=64 time=.2507 ms
68 bytes from 198.51.100.1: icmp_seq=5 ttl=64 time=3.2822 ms
Statistics: 5 sent, 5 received, 0% packet loss

The command argument labeled-unicast takes the ICMP requests through a labeled path while validating IP connectivity and hence, it prepends an MPLS label.

Validating BGP Adjacency, Routes and Reachability

Run the following commands to show BGP session and state.

supervisor@rtbrick>C-BNG.rtbrick.net: op> show bgp peer
Instance: default
  Peer                                     Remote AS    State         Up/Down Time               PfxRcvd              PfxSent
  198.51.100.3                             4200000001   Established   0d:00h:04m:14s             1150000              5

After configuring BGP, check the IPv4 unicast routes, populated by BGP using the following command:

supervisor@rtbrick>C-BNG.rtbrick.net: op> show route ipv4 unicast source bgp instance default show route ipv4 unicast source bgp instance default
Instance: default, AFI: ipv4, SAFI: unicast
Prefix/Label                                Source            Pref    Next Hop                                    Interface
172.16.0.0/24                               bgp               200     198.51.100.2                                ifl-0/0/1/10
172.16.1.0/24                               bgp               200     198.51.100.2                                ifl-0/0/1/10
172.16.2.0/24                               bgp               200     198.51.100.2                                ifl-0/0/1/10
172.16.3.0/24                               bgp               200     198.51.100.2                                ifl-0/0/1/10
172.16.4.0/24                               bgp               200     198.51.100.2                                ifl-0/0/1/10
172.16.5.0/24                               bgp               200     198.51.100.2                                ifl-0/0/1/10
172.16.6.0/24                               bgp               200     198.51.100.2                                ifl-0/0/1/10
172.16.7.0/24                               bgp               200     198.51.100.2                                ifl-0/0/1/10
172.16.8.0/24                               bgp               200     198.51.100.2                                ifl-0/0/1/10
172.16.9.0/24                               bgp               200     198.51.100.2                                ifl-0/0/1/10
<...>

This command will list all the 1 million IPv4 BGP internet prefixes.

Pinging an IPv4 route (source: bgp) from the C-BNG.

supervisor@rtbrick>C-BNG.rtbrick.net: op> ping 172.16.1.0
68 bytes from 172.16.1.0: icmp_seq=1 ttl=64 time=4.3976 ms
68 bytes from 172.16.1.0: icmp_seq=2 ttl=64 time=1.5301 ms
68 bytes from 172.16.1.0: icmp_seq=3 ttl=64 time=3.0536 ms
68 bytes from 172.16.1.0: icmp_seq=4 ttl=64 time=5.3049 ms
68 bytes from 172.16.1.0: icmp_seq=5 ttl=64 time=4.4273 ms
Statistics: 5 sent, 5 received, 0% packet loss

Check the IPv6 unicast routes, populated by BGP using the following command:

supervisor@rtbrick>C-BNG.rtbrick.net: op> show route ipv6 unicast source bgp instance default show route ipv6 unicast source bgp instance default
Instance: default, AFI: ipv6, SAFI: unicast
Prefix/Label                                Source            Pref    Next Hop                                    Interface
2004::/48                                   bgp               200     198.51.100.2                                ifl-0/0/1/10
2004:0:1::/48                               bgp               200     198.51.100.2                                ifl-0/0/1/10
2004:0:2::/48                               bgp               200     198.51.100.2                                ifl-0/0/1/10
2004:0:3::/48                               bgp               200     198.51.100.2                                ifl-0/0/1/10
2004:0:4::/48                               bgp               200     198.51.100.2                                ifl-0/0/1/10
2004:0:5::/48                               bgp               200     198.51.100.2                                ifl-0/0/1/10
2004:0:6::/48                               bgp               200     198.51.100.2                                ifl-0/0/1/10
2004:0:7::/48                               bgp               200     198.51.100.2                                ifl-0/0/1/10
2004:0:8::/48                               bgp               200     198.51.100.2                                ifl-0/0/1/10
2004:0:9::/48                               bgp               200     198.51.100.2                                ifl-0/0/1/10
2004:0:a::/48                               bgp               200     198.51.100.2                                ifl-0/0/1/10

<...>

Pinging an IPv6 route (source: bgp) from the C-BNG.

supervisor@rtbrick>C-BNG.rtbrick.net: op> ping 2004:0:1::
68 bytes from 2004:0:1::: icmp_seq=1 ttl=255 time=2.2185 ms
68 bytes from 2004:0:1::: icmp_seq=2 ttl=255 time=1.1854 ms
68 bytes from 2004:0:1::: icmp_seq=3 ttl=255 time=5.3917 ms
68 bytes from 2004:0:1::: icmp_seq=4 ttl=255 time=2.3068 ms
68 bytes from 2004:0:1::: icmp_seq=5 ttl=255 time=5.4419 ms
Statistics: 5 sent, 5 received, 0% packet loss