The Cisco 1700, 2600, and 3600 Series Routers support the Asymmetric Digital Subscriber Line (ADSL) WAN Interface Card (WIC). All three platforms are configured essentially the same, but there are differences in hardware and in the Cisco IOS® Software release required for each one. Throughout this document the Cisco 1700/2600/3600 will be called the "Cisco ADSL WIC."
In Cisco IOS® Software Release 12.1(3)XG, a Point-to-Point Protocol over Ethernet (PPPoE) client feature was introduced for the Cisco ADSL WIC. This feature allows the PPPoE functionality to be moved to the router. Multiple PCs can be installed behind the Cisco ADSL WIC and before their traffic is sent to the PPPoE session, it can be encrypted, filtered, etc. and Network Address Translation (NAT) can run.
This document shows a PPPoE client configured on the Asynchronous Transfer Mode (ATM) interface (the DSL interface) of the Cisco ADSL WIC.
The configuration on the Cisco 6400 node route processor (NRP) can also be used on another router used as an aggregator and with an ATM interface.
This configuration was developed and tested using the hardware and software versions below.
To support the ADSL WIC on the Cisco 2600/3600, the following hardware is required:
| 2600 | 3600 |
| Chassis WIC slots | NM-1FE1R2W |
| NM-2W | NM-1FE2W |
| NM-2FE2W | |
| NM-2W |
Important: For the Cisco 3600, the following do not support the ADSL WIC:
To support the ADSL WIC, the following minimum Cisco IOS Software releases are required:
When you download the image for the Cisco 1700, make sure you select the image name of 1700. Do not download a 1720 or a 1750 image; the features will not support the ADSL WIC.
PPPoE is configured on the Cisco ADSL WIC with the VPDN commands. Make sure you configure these commands first.
Note: For information about changing the size of the maximum transmission unit (MTU), see Troubleshooting MTU Size in PPPoE Dialin Connectivity.
| Cisco ADSL WIC |
|---|
! vpdn enable no vpdn logging !--- default ! vpdn-group pppoe request-dialin !--- we are the PPPoE client requesting to establish !--- a session with the aggregation unit (6400 NRP) protocol pppoe ! !--- internal Ethernet network ! interface FastEthernet0 ip address 10.92.1.182 255.255.255.0 ip nat inside !--- DSL interface ! interface ATM0 no ip address no atm ilmi-keepalive bundle-enable dsl operating-mode auto hold-queue 224 in !--- all defaults !--- PPPoE runs on top of AAL5SNAP, but the !--- encap aal5snap command is not used. ! interface ATM0.1 point-to-point pvc 1/1 pppoe-client dial-pool-number 1 !--- pvc 1/1 is an example value that must be changed !--- to match the value used by the ISP ! !--- The PPPoE client code ties into a dialer interface upon !--- which a virtual-access interface is cloned. ! interface Dialer1 ip address negotiated ip mtu 1492 !--- Ethernet MTU default = 1500 (1492 + PPPoE headers = 1500) ip nat outside encapsulation ppp dialer pool 1 !--- ties to atm interface ppp authentication chap callin ppp chap hostname <username> ppp chap password <password> ! !--- The ISP will instruct you regarding !--- the type of authentication to use. !--- To change from PPP CHAP to PPP PAP, !--- replace the following three lines: !--- ppp authentication chap callin !--- ppp chap hostname <username> !--- ppp chap password <password> !--- with the following two lines: !--- ppp authentication pap callin !--- ppp pap sent-username <username> password <password> !--- For NAT we are going to overload on the Dialer1 !--- interface and add a default route out !--- since dialer ip address can change ip nat inside source list 1 interface Dialer1 overload ip classless ip route 0.0.0.0 0.0.0.0 dialer1 no ip http server ! access-list 1 permit 10.92.1.0 0.0.0.255 !--- for NAT ! |
| Cisco 6400 |
|---|
*** local ppp user !--- or you could use aaa username <username> password <password> !--- begin with the VPDN commands !--- notice that we are binding the PPPoE here to !--- a virtual-template instead of on the ATM interface !--- You cannot (at this time) use more than one !--- virtual-template (or vpdn group) for PPPoE !--- beginning with the VPDN commands vpdn enable no vpdn logging ! vpdn-group pppoe accept-dialin !--- PPPoE server mode protocol pppoe virtual-template 1 ! ! interface ATM0/0/0 no ip address no atm ilmi-keepalive hold-queue 500 in !--- The binding to the virtual-template !--- interface is configured in the vpdn group ! interface ATM0/0/0.182 point-to-point pvc 1/82 encapsulation aal5snap !--- need the command on the server side protocol pppoe ! ! !--- virtual-template used instead of dialer interface ! interface Virtual-Template1 ip unnumbered Loopback10 ip mtu 1492 peer default ip address pool ippool ppp authentication chap ! ! interface Loopback10 ip address 8.8.8.1 255.255.255.0 ! ip local pool ippool 9.9.9.1 9.9.9.5 |
To debug the PPPoE client on the Cisco ADSL WIC or Cisco 6400, you must consider the protocol stack. You could troubleshoot beginning at the bottom.
Make sure the line is up and trained.
show int atm0
ATM0 is up, line protocol is up
Hardware is PQUICC_SAR (with Alcatel ADSL Module)
show dsl interface atm0
!--- Look for "Showtime" in the first few lines.
ATU-R (DS) ATU-C (US)
Modem Status: Showtime (DMTDSL_SHOWTIME)
If the ATM interface is up, you can use the debug atm packets command to see if anything is coming in from the ISP.
Note: You will not see outgoing packets with this command because of the way the packets are processed.
You should see output similar to the following, with the same Type, SAP, CTL, and OUI fields showing that the incoming ATM packet is AAL5SNAP.
debug atm packet 03:21:32: ATM0(I): VCD:0x2 VPI:0x1 VCI:0x1 Type:0x0 SAP:AAAA CTL:03 OUI:0080C2 TYPE:0007 Length:0x30 03:21:32: 0000 0050 7359 35B7 0001 96A4 84AC 8864 1100 0001 000E C021 09AB 000C 0235 03:21:32: 279F 0000 0000 03:21:32:
Complete Ethernet frames are in the AAL5SNAP packets. There is no debug ethernet packet command, but we should perform some VPDN debugs to see the PPPoE frames.
For reference, an Ethernet frame which is a PPPoE frame will contain one of two ethertypes:
One important note is that there are two sessions in PPPoE. The PPPoE session which is a VPDN L2TP type session and the PPP session. So, to establish PPPoE we have a PPPoE session establishment phase and a PPP session establishment phase.
Termination usually involves a PPP termination phase and a PPPoE termination phase.
The PPPoE establishment phase consists of identifying the PPPoE client and server (the MAC addresses), and assigning a session ID. After that is complete, the normal PPP establishment will occur just like any other PPP connection.
To debug, we can use VPDN PPPoE debugs to determine if we the PPPoE connect phase is successful.
#debug vpdn pppoe-events 06:17:58: Sending PADI: vc=1/1 !--- A broadcast Ethernet frame (in our case encapsulated in ATM) !--- requesting a PPPoE server, "Are there any PPPoE servers out there??" 06:18:00: PPPOE: we've got our pado and the pado timer went off !--- This is a unicast reply from a PPPoE server (very similar to a DHCP offer). 06:18:00: OUT PADR from PPPoE tunnel !--- This is a unicast reply accepting the offer. 06:18:00: IN PADS from PPPoE tunnel !--- This is a confirmation and completes the establishment.
The PPP establishment will now begin as in any other PPP initiation. After the PPPoE session is established, you can use show vpdn commands to get the status.
#show vpdn %No active L2TP tunnels %No active L2F tunnels PPPoE Tunnel and Session Information Total tunnels 1 sessions 1 PPPoE Tunnel Information Session count: 1 PPPoE Session Information SID RemMAC LocMAC Intf VASt OIntf VC
1 0050.7359.35b7 0001.96a4.84ac Vi1 UP AT0 1 1
You can get packet count information using the show vpdn session all command.
show vpdn session all %No active L2TP tunnels %No active L2F tunnels PPPoE Session Information Total tunnels 1 sessions 1 session id: 1 local MAC address: 0001.96a4.84ac, remote MAC address: 0050.7359.35b7 virtual access interface: Vi1, outgoing interface: AT0, vc: 1/1 1656 packets sent, 1655 received, 24516 bytes sent, 24486 received
Other debug commands:
After the PPPoE session has been established, the PPP debugs are the same as for any other PPP establishment.
The same debug ppp negotiation and debug ppp authentication commands are used. Following is sample output.
Note: In the following sample, the hostname is "client1" and the name of the remote Cisco 6400 is "nrp-b".
06:36:03: Vi1 PPP: Treating connection as a callout 06:36:03: Vi1 PPP: Phase is ESTABLISHING, Active Open [0 sess, 1 load] 06:36:03: Vi1 PPP: No remote authentication for call-out 06:36:03: Vi1 LCP: O CONFREQ [Closed] id 1 len 10 06:36:03: Vi1 LCP: MagicNumber 0x03013D43 (0x050603013D43) 06:36:03: Vi1 LCP: I CONFACK [REQsent] id 1 len 10 06:36:03: Vi1 LCP: MagicNumber 0x03013D43 (0x050603013D43) 06:36:05: Vi1 LCP: I CONFREQ [ACKrcvd] id 2 len 15 06:36:05: Vi1 LCP: AuthProto CHAP (0x0305C22305) 06:36:05: Vi1 LCP: MagicNumber 0x65E315E5 (0x050665E315E5) 06:36:05: Vi1 LCP: O CONFACK [ACKrcvd] id 2 len 15 06:36:05: Vi1 LCP: AuthProto CHAP (0x0305C22305) 06:36:05: Vi1 LCP: MagicNumber 0x65E315E5 (0x050665E315E5) 06:36:05: Vi1 LCP: State is Open 06:36:05: Vi1 PPP: Phase is AUTHENTICATING, by the peer [0 sess, 1 load] 06:36:05: Vi1 CHAP: I CHALLENGE id 9 len 26 from "nrp-b" 06:36:05: Vi1 CHAP: Using alternate hostname client1 06:36:05: Vi1 CHAP: Username nrp-b not found 06:36:05: Vi1 CHAP: Using default password 06:36:05: Vi1 CHAP: O RESPONSE id 9 len 28 from "client1" 06:36:05: Vi1 CHAP: I SUCCESS id 9 len 4 06:36:05: Vi1 PPP: Phase is FORWARDING [0 sess, 1 load] 06:36:05: Vi1 PPP: Phase is AUTHENTICATING [0 sess, 1 load] 06:36:05: Vi1 PPP: Phase is UP [0 sess, 1 load] 06:36:05: Vi1 IPCP: O CONFREQ [Closed] id 1 len 10 06:36:05: Vi1 IPCP: Address 0.0.0.0 (0x030600000000) 06:36:05: Vi1 CDPCP: O CONFREQ [Closed] id 1 len 4 06:36:05: Vi1 IPCP: I CONFREQ [REQsent] id 1 len 10 06:36:05: Vi1 IPCP: Address 8.8.8.1 (0x030608080801) 06:36:05: Vi1 IPCP: Address 8.8.8.1 (0x030608080801) 06:36:05: Vi1 IPCP: Address 9.9.9.2 (0x030609090902) 06:36:05: Vi1 IPCP: O CONFREQ [ACKsent] id 2 len 10 06:36:05: Vi1 IPCP: Address 9.9.9.2 (0x030609090902) 06:36:05: Vi1 LCP: I PROTREJ [Open] id 3 len 10 protocol CDPCP (0x820701010004) 06:36:05: Vi1 CDPCP: State is Closed 06:36:05: Vi1 IPCP: I CONFACK [ACKsent] id 2 len 10 06:36:05: Vi1 IPCP: Address 9.9.9.2 (0x030609090902) 06:36:05: Vi1 IPCP: State is Open 06:36:05: Di1 IPCP: Install negotiated IP interface address 9.9.9.2 06:36:05: Di1 IPCP: Install route to 8.8.8.1 06:36:06: %LINEPROTO-5-UPDOWN: Line protocol on Interface Virtual-Access1, changed state to up
To debug the Cisco 6400 (the PPPoE server), you can use the same bottom-up procedure used for the Cisco ADSL WIC (the client). The difference is in the DSL physical layer, where you need to check the DSLAM.
To check the DSL physical layer, you need to see the DSL statistics on the DSLAM. For Cisco DSLAMs, the show dsl interface command can be used.
On the Cisco 6400 side, you can also use a debug atm packet command and enable the Cisco 6400 for a specific PVC.
debug atm packet interface atm 0/0/0.182 vc 1/82
You should see output similar to the following, with the same Type, SAP, CTL, and OUI fields showing that the incoming ATM packet is AAL5SNAP.
4d04h: ATM0/0/0.182(I): VCD:0x3 VPI:0x1 VCI:0x52 Type:0x900 SAP:AAAA CTL:03 OUI:0080C2 TYPE:0007 Length:0x30 4d04h: 0000 0001 96A4 84AC 0050 7359 35B7 8864 1100 0001 000E C021 0A2E 000C 65E3 4d04h: 15E5 0000 0000
Note: You will not see outgoing packets with this command because of the way the packets are processed.
The same VPDN show commands and debugs used on the Cisco ADSL WIC can be used on the Cisco 6400 to look at the PPPoE establishment.
#debug vpdn pppoe-events 4d04h: IN PADI from PPPoE tunnel 4d04h: OUT PADO from PPPoE tunnel 4d04h: IN PADR from PPPoE tunnel 4d04h: PPPoE: Create session 4d04h: PPPoE: VPN session created. 4d04h: OUT PADS from PPPoE tunnel #show vpdn %No active L2TP tunnels %No active L2F tunnels PPPoE Tunnel and Session Information Total tunnels 1 sessions 1 PPPoE Tunnel Information Session count: 1 PPPoE Session Information SID RemMAC LocMAC Intf VASt OIntf VC 1 0001.96a4.84ac 0050.7359.35b7 Vi4 UP AT0/0/0 1 82 #show vpdn session all nrp-b#show vpdn session all %No active L2TP tunnels %No active L2F tunnels PPPoE Session Information Total tunnels 1 sessions 1 session id: 1 local MAC address: 0050.7359.35b7, remote MAC address: 0001.96a4.84ac virtual access interface: Vi4, outgoing interface: AT0/0/0, vc: 1/82 30 packets sent, 28 received, 422 bytes sent, 395 received
Other debug commands:
Following is PPP debug output from the Cisco 6400 that corresponds to the earlier debug from the Cisco ADSL WIC.
debug ppp negotiation and debug ppp authentication4d04h: Vi2 PPP: Treating connection as a dedicated line 4d04h: Vi2 PPP: Phase is ESTABLISHING, Active Open [0 sess, 1 load] 4d04h: Vi2 LCP: O CONFREQ [Closed] id 1 len 15 4d04h: Vi2 LCP: AuthProto CHAP (0x0305C22305) 4d04h: Vi2 LCP: MagicNumber 0x65F62814 (0x050665F62814) 4d04h: Vi2 LCP: I CONFREQ [REQsent] id 1 len 10 4d04h: Vi2 LCP: MagicNumber 0x03144FF9 (0x050603144FF9) 4d04h: Vi2 LCP: O CONFACK [REQsent] id 1 len 10 4d04h: Vi2 LCP: MagicNumber 0x03144FF9 (0x050603144FF9) 4d04h: Vi3 LCP: I ECHOREQ [Open] id 60 len 8 magic 0xA60C0000 4d04h: Vi3 LCP: O ECHOREP [Open] id 60 len 8 magic 0x51A0BEF6 4d04h: Vi2 LCP: TIMEout: State ACKsent 4d04h: Vi2 LCP: O CONFREQ [ACKsent] id 2 len 15 4d04h: Vi2 LCP: AuthProto CHAP (0x0305C22305) 4d04h: Vi2 LCP: MagicNumber 0x65F62814 (0x050665F62814) 4d04h: Vi2 LCP: I CONFACK [ACKsent] id 2 len 15 4d04h: Vi2 LCP: AuthProto CHAP (0x0305C22305) 4d04h: Vi2 LCP: MagicNumber 0x65F62814 (0x050665F62814) 4d04h: Vi2 LCP: State is Open 4d04h: Vi2 PPP: Phase is AUTHENTICATING, by this end [0 sess, 1 load] 4d04h: Vi2 CHAP: O CHALLENGE id 10 len 26 from "nrp-b" 4d04h: Vi2 CHAP: I RESPONSE id 10 len 28 from "client1" 4d04h: Vi2 PPP: Phase is FORWARDING [0 sess, 1 load] 4d04h: Vi2 PPP: Phase is AUTHENTICATING [0 sess, 1 load] 4d04h: Vi2 CHAP: O SUCCESS id 10 len 4 4d04h: Vi2 PPP: Phase is UP [0 sess, 1 load] 4d04h: Vi2 IPCP: O CONFREQ [Closed] id 1 len 10 4d04h: Vi2 IPCP: Address 8.8.8.1 (0x030608080801) 4d04h: Vi2 IPCP: I CONFREQ [REQsent] id 1 len 10 4d04h: Vi2 IPCP: Address 0.0.0.0 (0x030600000000) 4d04h: Vi2 IPCP: Pool returned 9.9.9.2 4d04h: Vi2 IPCP: O CONFNAK [REQsent] id 1 len 10 4d04h: Vi2 IPCP: Address 9.9.9.2 (0x030609090902) 4d04h: Vi2 CDPCP: I CONFREQ [Not negotiated] id 1 len 4 4d04h: Vi2 LCP: O PROTREJ [Open] id 3 len 10 protocol CDPCP (0x820701010004) 4d04h: Vi2 IPCP: I CONFACK [REQsent] id 1 len 10 4d04h: Vi2 IPCP: Address 8.8.8.1 (0x030608080801) 4d04h: Vi2 IPCP: I CONFREQ [ACKrcvd] id 2 len 10 4d04h: Vi2 IPCP: Address 9.9.9.2 (0x030609090902) 4d04h: Vi2 IPCP: O CONFACK [ACKrcvd] id 2 len 10 4d04h: Vi2 IPCP: Address 9.9.9.2 (0x030609090902) 4d04h: Vi2 IPCP: State is Open 4d04h: Vi2 IPCP: Install route to 9.9.9.2 4d04h: %LINEPROTO-5-UPDOWN: Line protocol on Interface Virtual-Access2, changed state to up
All contents are Copyright © 1992--2001 Cisco Systems, Inc. All rights reserved. Important Notices and Privacy Statement.