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infra-estrutura:cisco:cisco_l2tp

Configurando túnel L2TP

L2TPv3 (Layer Two Tunneling Protocol Version 3) é um ponto-a-ponto camada 2 sobre um tunnel ip(camada 3).

Por este túnel camada 2 você pode trafegar protocolos como: Ethernet, Frame-relay, ATM, HDLC, PPP, etc. Isto é útil caso você precise que duas subnets remotas fiquei no mesmo dominio de broadcast (estender uma subnet para outro site), ou ainda para aplicações que requerem que as duas subnets estejam na mesma subnet.

L2TPv3 é um padrão IETF(RFC3931) com o número de protocolo 115(https://www.iana.org/assignments/protocol-numbers/protocol-numbers.xhtml) e combina duas tecnologias:

  • Cisco L2F (Layer 2 Forwarding)
  • Microsoft Point to Point Tunneling Protocol (PPTP)

Para teste de um túnel L2TP utilizaremos o seguinte ambiente abaixo.

Configurando R1

Para a configuração do R1 utilizaremos a seguinte conf.

pseudowire-class R1_R2
 encapsulation l2tpv3
 ip local interface Ethernet0/1
!
interface Ethernet0/0
 no ip address
 no keepalive
 xconnect 192.168.12.2 12 pw-class R1_R2
!
interface Ethernet0/1
 ip address 192.168.12.1 255.255.255.0
!

Configurando R2

Para o R2 da mesma forma

pseudowire-class R2_R1
 encapsulation l2tpv3
 ip local interface Ethernet0/1
!
interface Ethernet0/0
 no ip address
 no keepalive
 xconnect 192.168.12.1 12 pw-class R2_R1
!
interface Ethernet0/1
 ip address 192.168.12.2 255.255.255.0
!

Testando o túnel L2TP

Pingando a partir do 192.168.1.101 para o endereço 192.168.1.102


PC-1> ping 192.168.1.102
84 bytes from 192.168.1.102 icmp_seq=1 ttl=64 time=1.500 ms
84 bytes from 192.168.1.102 icmp_seq=2 ttl=64 time=1.500 ms
84 bytes from 192.168.1.102 icmp_seq=3 ttl=64 time=1.501 ms
84 bytes from 192.168.1.102 icmp_seq=4 ttl=64 time=1.500 ms
84 bytes from 192.168.1.102 icmp_seq=5 ttl=64 time=1.500 ms

PC-1>

Pingando a partir do 192.168.1.102 para o endereço 192.168.1.101

PC-2> ping 192.168.1.101
84 bytes from 192.168.1.101 icmp_seq=1 ttl=64 time=1.500 ms
84 bytes from 192.168.1.101 icmp_seq=2 ttl=64 time=1.500 ms
84 bytes from 192.168.1.101 icmp_seq=3 ttl=64 time=1.500 ms
84 bytes from 192.168.1.101 icmp_seq=4 ttl=64 time=1.501 ms
84 bytes from 192.168.1.101 icmp_seq=5 ttl=64 time=1.500 ms

PC-2>

Visualizando o tunel L2TP

Visualizando a sessão L2TP(show l2tp e show l2tp session)

R2#show l2tp

L2TP Tunnel and Session Information Total tunnels 1 sessions 1

LocTunID   RemTunID   Remote Name   State  Remote Address  Sessn L2TP Class/
                                                           Count VPDN Group
998253310  1122394201 R1            est    192.168.12.1    1     l2tp_default_cl

LocID      RemID      TunID      Username, Intf/      State  Last Chg Uniq ID
                                 Vcid, Circuit
4205256635 472596089  998253310  12, Et0/0            est    00:23:51 1
R2#
R2#
R2#show l2tp session

L2TP Session Information Total tunnels 1 sessions 1

LocID      RemID      TunID      Username, Intf/      State  Last Chg Uniq ID
                                 Vcid, Circuit
4205256635 472596089  998253310  12, Et0/0            est    00:23:55 1
R2#

* show l2tp session all*

R2#show l2tp session all

L2TP Session Information Total tunnels 1 sessions 1

Session id 4205256635 is up, logical session id 32768, tunnel id 998253310
  Remote session id is 472596089, remote tunnel id 1122394201
  Locally initiated session
  Unique ID is 1
Session Layer 2 circuit, type is Ethernet, name is Ethernet0/0
  Session vcid is 12
  Circuit state is UP
    Local circuit state is UP
    Remote circuit state is UP
Call serial number is 6800001
Remote tunnel name is R1
  Internet address is 192.168.12.1
Local tunnel name is R2
  Internet address is 192.168.12.2
IP protocol 115
  Session is L2TP signaled
  Session state is established, time since change 00:24:46
    24 Packets sent, 24 received
    2860 Bytes sent, 2860 received
  Last clearing of counters never
  Counters, ignoring last clear:
    24 Packets sent, 24 received
    2860 Bytes sent, 2860 received
    Receive packets dropped:
      out-of-order:             0
      other:                    0
      total:                    0
    Send packets dropped:
      exceeded session MTU:     0
      other:                    0
      total:                    0
  DF bit off, ToS reflect disabled, ToS value 0, TTL value 255
  Sending UDP checksums are disabled
  Received UDP checksums are verified
  No session cookie information available
  FS cached header information:
    encap size = 24 bytes
    45000014 00000000 ff732223 c0a80c02
    c0a80c01 1c2b3e79
  Sequencing is off
  Conditional debugging is disabled
  SSM switch id is 4096, SSM segment id is 8193
R2#

*show l2tun*

R2#show l2tun counters tunnel l2tp
Global L2TP tunnel control message statistics:

          XMIT         RE-XMIT      RCVD         DROP
          ==========   ==========   ==========   ==========
ZLB       2            0            27           0
SCCRQ     1            1            0            0
SCCRP     0            0            1            0
SCCCN     1            0            0            0
StopCCN   0            0            0            0
Hello     24           0            0            0
OCRQ      0            0            0            0
OCRP      0            0            0            0
OCCN      0            0            0            0
ICRQ      1            0            0            0
ICRP      0            0            1            0
ICCN      1            0            0            0
CDN       0            0            0            0
WEN       0            0            0            0
SLI       1            0            1            0
EXP ACK   0            0            0            0
SRRQ      0            0            0            0
SRRP      0            0            0            0
CiscoACK  0            0            0            0
Total     31           1            30           0

R2#

*show l2tun session brief*

R2#show l2tun session brief

L2TP Session Information Total tunnels 1 sessions 1

LocID      TunID      Peer-address    State     Username, Intf/
                                      sess/cir  Vcid, Circuit
4205256635 998253310  192.168.12.1    est,UP    12, Et0/0
R2#

* show xconnect *

R2#show xconnect interface ethernet 0/0
Legend:    XC ST=Xconnect State  S1=Segment1 State  S2=Segment2 State
  UP=Up       DN=Down            AD=Admin Down      IA=Inactive
  SB=Standby  RV=Recovering      NH=No Hardware

XC ST  Segment 1                         S1 Segment 2                         S2
------+---------------------------------+--+---------------------------------+--
UP     ac   Et0/0(Ethernet)              UP l2tp 192.168.12.1:12              UP
R2#
R2#
R2#show xconnect interface ethernet 0/1
Legend:    XC ST=Xconnect State  S1=Segment1 State  S2=Segment2 State
  UP=Up       DN=Down            AD=Admin Down      IA=Inactive
  SB=Standby  RV=Recovering      NH=No Hardware

XC ST  Segment 1                         S1 Segment 2                         S2
------+---------------------------------+--+---------------------------------+--
Xconnect entry does not exist
R2#
R2#show xconnect peer 192.168.12.1 all
Legend:    XC ST=Xconnect State  S1=Segment1 State  S2=Segment2 State
  UP=Up       DN=Down            AD=Admin Down      IA=Inactive
  SB=Standby  RV=Recovering      NH=No Hardware

XC ST  Segment 1                         S1 Segment 2                         S2
------+---------------------------------+--+---------------------------------+--
UP     ac   Et0/0(Ethernet)              UP l2tp 192.168.12.1:12              UP
R2#

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infra-estrutura/cisco/cisco_l2tp.txt · Última modificação: 2019/05/19 16:22 por ricardobarbosams