cisco+frrouting vpn/bgp+mpls ibgp

README.md

cisco+frrouting vpn/bgp+mpls ibgp

• with next-hop-self
• with loopback
• with ldp
• without bgp labeled-unicast
• without route-reflector
• without multi-hop ebgp

Linux の MPLS は loopback を使うことが前提になっている。Linux では LDP を動作させなくても 192.168.0.1 が label 付きパケットを受け取るという前提で動作してしまう。 Cisco は LDP を動作させてから疎通するようになる。以下は LDP をオンにする前後の状態。

before

R1#show mpls ip binding all detail
  100.0.0.1/32, rev 2, chkpt: none
        in label:     imp-null   (owner LDP)
  100.0.0.2/32, rev 6, chkpt: none
        in label:     16         (owner LDP)
  192.168.0.0/24, rev 4, chkpt: none
        in label:     imp-null   (owner LDP)
R1#show mpls ldp bindings
  lib entry: 100.0.0.1/32, rev 2
        local binding:  label: imp-null
  lib entry: 100.0.0.2/32, rev 6
        local binding:  label: 16
  lib entry: 192.168.0.0/24, rev 4
        local binding:  label: imp-null
R1#show mpls forwarding-table
Local  Outgoing      Prefix            Bytes Label   Outgoing   Next Hop
Label  Label or VC   or Tunnel Id      Switched      interface
16     No Label      100.0.0.2/32      0             Fa0/0      192.168.0.2
17     No Label      192.168.1.0/24[V] 0             aggregate/A

after

R1#show mpls ip binding all detail
  100.0.0.1/32, rev 2, chkpt: none
        in label:     imp-null   (owner LDP)
          Advertised to:
          100.0.0.2:0
        out label:    16        lsr: 100.0.0.2:0
  100.0.0.2/32, rev 6, chkpt: none
        in label:     16         (owner LDP)
          Advertised to:
          100.0.0.2:0
        out label:    imp-null  lsr: 100.0.0.2:0      inuse
  192.168.0.0/24, rev 4, chkpt: none
        in label:     imp-null   (owner LDP)
          Advertised to:
          100.0.0.2:0
        out label:    imp-null  lsr: 100.0.0.2:0
R1#show mpls ldp bindings
  lib entry: 100.0.0.1/32, rev 2
        local binding:  label: imp-null
        remote binding: lsr: 100.0.0.2:0, label: 16
  lib entry: 100.0.0.2/32, rev 6
        local binding:  label: 16
        remote binding: lsr: 100.0.0.2:0, label: imp-null
  lib entry: 192.168.0.0/24, rev 4
        local binding:  label: imp-null
        remote binding: lsr: 100.0.0.2:0, label: imp-null
R1#show mpls forwarding-table
Local  Outgoing      Prefix            Bytes Label   Outgoing   Next Hop
Label  Label or VC   or Tunnel Id      Switched      interface
16     Pop Label     100.0.0.2/32      0             Fa0/0      192.168.0.2
17     No Label      192.168.1.0/24[V] 0             aggregate/A

r1.ios

version 12.4
ip cef

ip vrf A
  rd 65000:1
  route-target both 65000:100

interface lo 0
  ip addr 100.0.0.1 255.255.255.255

interface f 0/0
  ip addr 192.168.0.1 255.255.255.0
  mpls ip
  no shutdown

interface e 1/0
  ip vrf forwarding A
  ip addr 192.168.1.1 255.255.255.0
  no shutdown

router bgp 65000
  neighbor 100.0.0.2 remote-as 65000
  neighbor 100.0.0.2 update-source lo0
  address-family vpnv4
    neighbor 100.0.0.2 activate
    neighbor 100.0.0.2 next-hop-self
  address-family ipv4 vrf A
    redistribute connected

ip route 100.0.0.2 255.255.255.255 192.168.0.2

end

r2.vtysh

int lo
  ip addr 100.0.0.2/32

int eth0
  ip addr 192.168.0.2/24

int eth1 vrf A
  ip addr 192.168.2.1/24

mpls ldp
  address-family ipv4
    discovery transport-address 100.0.0.2
    interface eth0

router bgp 65000
  neighbor 100.0.0.1 remote-as 65000
  neighbor 100.0.0.1 update-source lo
  address-family ipv4 vpn
    neighbor 100.0.0.1 activate
    neighbor 100.0.0.1 next-hop-self

router bgp 65000 vrf A
  address-family ipv4
    import vpn
    export vpn
    rd vpn export 65000:2
    rt vpn both 65000:100
    label vpn export auto
    redistribute connected

ip route 100.0.0.1/32 192.168.0.1

end