L2TPv3 Interworking
Layer 2 VPN (L2VPN) Interworking allows you to connect disparate attachment circuits. You can connect various types of L2 networks (Ethernet, VLAN, Frame Relay, ATM, PPP etc.) over L2TPV3. But it is supported on specific routers and line cards only. You can check Cisco documentation for specific requirements.
Here we will connect Site-1 Ethernet link to Site-2 Serial PPP link.
Topology
Configuration
R1 - Provider Edge Router connected to Customer Routers hostname R1 ! ip cef ! pseudowire-class PW-CLASS encapsulation l2tpv3 interworking ip ip local interface Loopback0 ! interface Loopback0 ip address 10.1.1.1 255.255.255.255 ! interface FastEthernet0/0 ip address 10.1.13.1 255.255.255.0 ip ospf network point-to-point ! interface FastEthernet0/1 description To Cust-A Site-1 R4 no ip address no keepalive xconnect 10.1.1.2 101 pw-class PW-CLASS ! router ospf 1 log-adjacency-changes network 10.1.0.0 0.0.255.255 area 0 ! R2 - Provider Edge Router connected to Customer Routers hostname R2 ! ip cef ! pseudowire-class PW-CLASS encapsulation l2tpv3 interworking ip ip local interface Loopback0 ! interface Loopback0 ip address 10.1.1.2 255.255.255.255 ! interface FastEthernet0/0 ip address 10.1.23.2 255.255.255.0 ip ospf network point-to-point ! interface Serial1/0 description To Cust-A Site-2 R5 no ip address encapsulation ppp serial restart-delay 0 xconnect 10.1.1.1 101 pw-class PW-CLASS ! router ospf 1 log-adjacency-changes network 10.1.0.0 0.0.255.255 area 0 ! R3 - Service Provider Core Network Router hostname R3 ! ip cef ! interface FastEthernet0/0 ip address 10.1.13.3 255.255.255.0 ip ospf network point-to-point ! interface FastEthernet0/1 ip address 10.1.23.3 255.255.255.0 ip ospf network point-to-point ! router ospf 1 log-adjacency-changes network 10.1.0.0 0.0.255.255 area 0 ! R4 - Customer-A Site-1 Edge Router hostname R4 ! interface FastEthernet0/0 ip address 172.16.4.4 255.255.255.0 ! interface FastEthernet0/1 ip address 172.16.45.1 255.255.255.252 ! router eigrp 100 network 172.16.0.0 ! R5 - Customer-A Site-2 Edge Router hostname R5 ! interface FastEthernet0/0 ip address 172.16.5.5 255.255.255.0 ! interface Serial1/0 ip address 172.16.45.2 255.255.255.252 encapsulation ppp serial restart-delay 0 ! router eigrp 100 network 172.16.0.0 !
Verification & Testing
R1#show l2tun tunnel all L2TP Tunnel Information Total tunnels 1 sessions 1 Tunnel id 3964089202 is up, remote id is 2104878685, 1 active sessions Locally initiated tunnel Tunnel state is established, time since change 00:36:16 Tunnel transport is IP (115) Remote tunnel name is R2 Internet Address 10.1.1.2, port 0 Local tunnel name is R1 Internet Address 10.1.1.1, port 0 L2TP class for tunnel is l2tp_default_class Counters, taking last clear into account: 475 packets sent, 475 received 28562 bytes sent, 28524 received Last clearing of counters never Counters, ignoring last clear: 475 packets sent, 475 received 28562 bytes sent, 28524 received Control Ns 37, Nr 9 Local RWS 1024 (default), Remote RWS 1024 Control channel Congestion Control is disabled Tunnel PMTU checking disabled Retransmission time 1, max 1 seconds Unsent queuesize 0, max 0 Resend queuesize 0, max 3 Total resends 1, ZLB ACKs sent 5 Total out-of-order dropped pkts 0 Total out-of-order reorder pkts 0 Total peer authentication failures 0 Current no session pak queue check 0 of 5 Retransmit time distribution: 0 1 0 0 0 0 0 0 0 Control message authentication is disabled R1#show l2tun session all L2TP Session Information Total tunnels 1 sessions 1 Session id 2788289264 is up, logical session id 32768, tunnel id 3964089202 Remote session id is 1736473654, remote tunnel id 2104878685 Locally initiated session Unique ID is 1 Session Layer 2 circuit, type is Ethernet, name is FastEthernet0/1 Session vcid is 101 Interworking type is IP Circuit state is UP Local circuit state is UP Remote circuit state is UP Call serial number is 959200001 Remote tunnel name is R2 Internet address is 10.1.1.2 Local tunnel name is R1 Internet address is 10.1.1.1 IP protocol 115 Session is L2TP signaled Session state is established, time since change 00:36:35 479 Packets sent, 480 received 28802 Bytes sent, 28824 received Last clearing of counters never Counters, ignoring last clear: 479 Packets sent, 480 received 28802 Bytes sent, 28824 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 ff73a572 0a010101 0a010102 67807c36 Sequencing is off Conditional debugging is disabled SSM switch id is 4096, SSM segment id is 8193 R2#show l2tun tunnel all L2TP Tunnel Information Total tunnels 1 sessions 1 Tunnel id 2104878685 is up, remote id is 3964089202, 1 active sessions Remotely initiated tunnel Tunnel state is established, time since change 00:36:54 Tunnel transport is IP (115) Remote tunnel name is R1 Internet Address 10.1.1.1, port 0 Local tunnel name is R2 Internet Address 10.1.1.2, port 0 L2TP class for tunnel is l2tp_default_class Counters, taking last clear into account: 484 packets sent, 484 received 29064 bytes sent, 29102 received Last clearing of counters never Counters, ignoring last clear: 484 packets sent, 484 received 29064 bytes sent, 29102 received Control Ns 9, Nr 37 Local RWS 1024 (default), Remote RWS 1024 Control channel Congestion Control is disabled Tunnel PMTU checking disabled Retransmission time 1, max 1 seconds Unsent queuesize 0, max 0 Resend queuesize 0, max 3 Total resends 0, ZLB ACKs sent 34 Total out-of-order dropped pkts 0 Total out-of-order reorder pkts 0 Total peer authentication failures 0 Current no session pak queue check 0 of 5 Retransmit time distribution: 0 0 0 0 0 0 0 0 0 Control message authentication is disabled R2#show l2tun session all L2TP Session Information Total tunnels 1 sessions 1 Session id 1736473654 is up, logical session id 65537, tunnel id 2104878685 Remote session id is 2788289264, remote tunnel id 3964089202 Remotely initiated session Unique ID is 1 Session Layer 2 circuit, type is PPP, name is Serial1/0 Session vcid is 101 Interworking type is IP Circuit state is UP Local circuit state is UP Remote circuit state is UP Call serial number is 959200001 Remote tunnel name is R1 Internet address is 10.1.1.1 Local tunnel name is R2 Internet address is 10.1.1.2 IP protocol 115 Session is L2TP signaled Session state is established, time since change 00:37:08 487 Packets sent, 487 received 29244 Bytes sent, 29282 received Last clearing of counters never Counters, ignoring last clear: 487 Packets sent, 487 received 29244 Bytes sent, 29282 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 ff73a572 0a010102 0a010101 a631eaf0 Sequencing is off Conditional debugging is disabled SSM switch id is 4096, SSM segment id is 8193
R4#sh int f0/1 FastEthernet0/1 is up, line protocol is up Hardware is i82543 (Livengood), address is ca03.3344.0006 (bia ca03.3344.0006) Internet address is 172.16.45.1/30 MTU 1500 bytes, BW 100000 Kbit/sec, DLY 100 usec, reliability 255/255, txload 1/255, rxload 1/255 Encapsulation ARPA, loopback not set Keepalive set (10 sec) Full-duplex, 100Mb/s, 100BaseTX/FX ARP type: ARPA, ARP Timeout 04:00:00 Last input 00:00:00, output 00:00:01, output hang never Last clearing of "show interface" counters never Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0 Queueing strategy: fifo Output queue: 0/40 (size/max) 5 minute input rate 0 bits/sec, 0 packets/sec 5 minute output rate 0 bits/sec, 0 packets/sec 785 packets input, 58107 bytes Received 8 broadcasts (0 IP multicasts) 0 runts, 0 giants, 0 throttles 0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored 0 watchdog 0 input packets with dribble condition detected 1219 packets output, 103455 bytes, 0 underruns 0 output errors, 0 collisions, 3 interface resets 0 unknown protocol drops 0 babbles, 0 late collision, 0 deferred 0 lost carrier, 0 no carrier 0 output buffer failures, 0 output buffers swapped out R5#sh int s1/0 Serial1/0 is up, line protocol is up Hardware is M4T Internet address is 172.16.45.2/30 MTU 1500 bytes, BW 1544 Kbit/sec, DLY 20000 usec, reliability 255/255, txload 1/255, rxload 1/255 Encapsulation PPP, LCP Open Open: IPCP, CDPCP, crc 16, loopback not set Keepalive set (10 sec) Restart-Delay is 0 secs Last input 00:00:03, output 00:00:03, output hang never Last clearing of "show interface" counters 01:00:27 Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0 Queueing strategy: weighted fair Output queue: 0/1000/64/0 (size/max total/threshold/drops) Conversations 0/1/256 (active/max active/max total) Reserved Conversations 0/0 (allocated/max allocated) Available Bandwidth 1158 kilobits/sec 5 minute input rate 0 bits/sec, 0 packets/sec 5 minute output rate 0 bits/sec, 0 packets/sec 1515 packets input, 61892 bytes, 0 no buffer Received 0 broadcasts (0 IP multicasts) 0 runts, 0 giants, 0 throttles 0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort 1585 packets output, 82294 bytes, 0 underruns 0 output errors, 0 collisions, 0 interface resets 0 unknown protocol drops 0 output buffer failures, 0 output buffers swapped out 0 carrier transitions DCD=up DSR=up DTR=up RTS=up CTS=up R4#ping 172.16.45.2 Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 172.16.45.2, timeout is 2 seconds: !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 68/94/148 ms R4#show ip eigrp neighbors EIGRP-IPv4 Neighbors for AS(100) H Address Interface Hold Uptime SRTT RTO Q Seq (sec) (ms) Cnt Num 0 172.16.45.2 Fa0/1 11 01:00:21 199 1194 0 3 R4#show ip route | beg Gate Gateway of last resort is not set 172.16.0.0/16 is variably subnetted, 5 subnets, 3 masks C 172.16.4.0/24 is directly connected, FastEthernet0/0 L 172.16.4.4/32 is directly connected, FastEthernet0/0 D 172.16.5.0/24 [90/30720] via 172.16.45.2, 01:00:42, FastEthernet0/1 C 172.16.45.0/30 is directly connected, FastEthernet0/1 L 172.16.45.1/32 is directly connected, FastEthernet0/1 R4#ping 172.16.5.5 source 172.16.4.4 Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 172.16.5.5, timeout is 2 seconds: Packet sent with a source address of 172.16.4.4 !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 40/76/168 ms
