[cisco-nas] L2TP & multink problem

Mark Johnson mljohnso at cisco.com
Mon May 3 14:49:18 EDT 2004


At 08:13 PM 5/3/2004 +0300, Tassos Chatzithomaoglou wrote:
>We have the following 2 cases.
>
>1. multilink is NOT enabled under dialer interface on LAC
>2. multilink is enabled under dialer interface on LAC
>
>LNS has multilink enabled under vt on both cases and "lcp renegotiation 
>always" configured under the appropriate vpdn group.
>
>The client uses WinXP & ISDN TA (with its own ppp stack) and has enabled 
>multilink on both..
>
>
>LAC = AS5300 (12.2(15)T11) & AS5350 (12.3(6))
>LNS = 7140 (12.3(6a))
>
>
>1st case
>--------
>LAC
>---
>ay  3 19:27:06.420: Se2:9 PPP: Using dialer call direction
>May  3 19:27:06.420: Se2:9 PPP: Treating connection as a callin
>May  3 19:27:06.420: Se2:9 PPP: Phase is ESTABLISHING, Passive Open
>May  3 19:27:06.420: Se2:9 LCP: State is Listen
>May  3 19:27:06.808: Se2:9 LCP: I CONFREQ [Listen] id 1 len 28
>May  3 19:27:06.808: Se2:9 LCP:    MagicNumber 0x261212E8 (0x0506261212E8)
>May  3 19:27:06.808: Se2:9 LCP:    Callback 6  (0x0D0306)
>May  3 19:27:06.808: Se2:9 LCP:    MRRU 1506 (0x110405E2)
>May  3 19:27:06.808: Se2:9 LCP:    EndpointDisc 4 Magic 
>(0x130B040406C31157F09327)
>May  3 19:27:06.808: Se2:9 LCP: O CONFREQ [Listen] id 14 len 14
>May  3 19:27:06.808: Se2:9 LCP:    AuthProto PAP (0x0304C023)
>May  3 19:27:06.808: Se2:9 LCP:    MagicNumber 0xD6A470C1 (0x0506D6A470C1)
>May  3 19:27:06.812: Se2:9 LCP: O CONFREJ [Listen] id 1 len 11
>May  3 19:27:06.812: Se2:9 LCP:    Callback 6  (0x0D0306)
>May  3 19:27:06.812: Se2:9 LCP:    MRRU 1506 (0x110405E2)
>May  3 19:27:06.844: Se2:9 LCP: I CONFACK [REQsent] id 14 len 14
>May  3 19:27:06.844: Se2:9 LCP:    AuthProto PAP (0x0304C023)
>May  3 19:27:06.844: Se2:9 LCP:    MagicNumber 0xD6A470C1 (0x0506D6A470C1)
>May  3 19:27:08.768: Se2:9 LCP: I CONFREQ [ACKrcvd] id 2 len 13
>May  3 19:27:08.768: Se2:9 LCP:    MagicNumber 0x261212E8 (0x0506261212E8)
>May  3 19:27:08.768: Se2:9 LCP:    Callback 6  (0x0D0306)
>May  3 19:27:08.768: Se2:9 LCP: O CONFREJ [ACKrcvd] id 2 len 7
>May  3 19:27:08.768: Se2:9 LCP:    Callback 6  (0x0D0306)
>May  3 19:27:08.804: Se2:9 LCP: I CONFREQ [ACKrcvd] id 3 len 10
>May  3 19:27:08.804: Se2:9 LCP:    MagicNumber 0x261212E8 (0x0506261212E8)
>May  3 19:27:08.804: Se2:9 LCP: O CONFACK [ACKrcvd] id 3 len 10
>May  3 19:27:08.804: Se2:9 LCP:    MagicNumber 0x261212E8 (0x0506261212E8)
>May  3 19:27:08.804: Se2:9 LCP: State is Open
>May  3 19:27:08.804: Se2:9 PPP: Phase is AUTHENTICATING, by this end
>
>
>
>LNS
>---
>May  3 19:27:08.910: ppp1570 PPP: Phase is ESTABLISHING
>May  3 19:27:08.910: ppp1570 LCP: O CONFREQ [Closed] id 1 len 24
>May  3 19:27:08.910: ppp1570 LCP:    AuthProto PAP (0x0304C023)
>May  3 19:27:08.910: ppp1570 LCP:    MagicNumber 0x17819888 (0x050617819888)
>May  3 19:27:08.910: ppp1570 LCP:    MRRU 1524 (0x110405F4)
>May  3 19:27:08.910: ppp1570 LCP:    EndpointDisc 1 mmp (0x1306016D6D70)
>May  3 19:27:08.926: ppp1570 LCP: I CONFREJ [REQsent] id 1 len 8
>May  3 19:27:08.926: ppp1570 LCP:    MRRU 1524 (0x110405F4)
>May  3 19:27:08.926: ppp1570 LCP: O CONFREQ [REQsent] id 2 len 20
>May  3 19:27:08.926: ppp1570 LCP:    AuthProto PAP (0x0304C023)
>May  3 19:27:08.926: ppp1570 LCP:    MagicNumber 0x17819888 (0x050617819888)
>May  3 19:27:08.926: ppp1570 LCP:    EndpointDisc 1 mmp (0x1306016D6D70)
>May  3 19:27:08.974: ppp1570 LCP: I CONFREQ [REQsent] id 6 len 10
>May  3 19:27:08.974: ppp1570 LCP:    MagicNumber 0x261212E8 (0x0506261212E8)
>May  3 19:27:08.974: ppp1570 LCP: O CONFACK [REQsent] id 6 len 10
>May  3 19:27:08.974: ppp1570 LCP:    MagicNumber 0x261212E8 (0x0506261212E8)
>May  3 19:27:08.978: ppp1570 LCP: I CONFACK [ACKsent] id 2 len 20
>May  3 19:27:08.978: ppp1570 LCP:    AuthProto PAP (0x0304C023)
>May  3 19:27:08.978: ppp1570 LCP:    MagicNumber 0x17819888 (0x050617819888)
>May  3 19:27:08.978: ppp1570 LCP:    EndpointDisc 1 mmp (0x1306016D6D70)
>May  3 19:27:08.978: ppp1570 LCP: State is Open
>May  3 19:27:08.978: ppp1570 PPP: Phase is AUTHENTICATING, by this end
>
>
>
>2nd case
>--------
>LAC
>---
>May  3 19:25:07.957: Se2:8 PPP: Using dialer call direction
>May  3 19:25:07.957: Se2:8 PPP: Treating connection as a callin
>May  3 19:25:07.957: Se2:8 PPP: Phase is ESTABLISHING, Passive Open
>May  3 19:25:07.957: Se2:8 LCP: State is Listen
>May  3 19:25:09.957: Se2:8 LCP: TIMEout: State Listen
>May  3 19:25:09.957: Se2:8 LCP: O CONFREQ [Listen] id 26 len 24
>May  3 19:25:09.957: Se2:8 LCP:    AuthProto PAP (0x0304C023)
>May  3 19:25:09.957: Se2:8 LCP:    MagicNumber 0xD6A2A84C (0x0506D6A2A84C)
>May  3 19:25:09.957: Se2:8 LCP:    MRRU 1524 (0x110405F4)
>May  3 19:25:09.957: Se2:8 LCP:    EndpointDisc 1 mmp (0x1306016D6D70)
>May  3 19:25:09.993: Se2:8 LCP: I CONFACK [REQsent] id 26 len 24
>May  3 19:25:09.993: Se2:8 LCP:    AuthProto PAP (0x0304C023)
>May  3 19:25:09.993: Se2:8 LCP:    MagicNumber 0xD6A2A84C (0x0506D6A2A84C)
>May  3 19:25:09.993: Se2:8 LCP:    MRRU 1524 (0x110405F4)
>May  3 19:25:09.993: Se2:8 LCP:    EndpointDisc 1 mmp (0x1306016D6D70)
>May  3 19:25:10.293: Se2:8 LCP: I CONFREQ [ACKrcvd] id 2 len 28
>May  3 19:25:10.293: Se2:8 LCP:    MagicNumber 0x3EA82025 (0x05063EA82025)
>May  3 19:25:10.293: Se2:8 LCP:    Callback 6  (0x0D0306)
>May  3 19:25:10.293: Se2:8 LCP:    MRRU 1506 (0x110405E2)
>May  3 19:25:10.293: Se2:8 LCP:    EndpointDisc 4 Magic 
>(0x130B0477EE0B102D1884F3)
>May  3 19:25:10.293: Se2:8 LCP: O CONFREJ [ACKrcvd] id 2 len 7
>May  3 19:25:10.293: Se2:8 LCP:    Callback 6  (0x0D0306)
>May  3 19:25:10.329: Se2:8 LCP: I CONFREQ [ACKrcvd] id 3 len 25
>May  3 19:25:10.329: Se2:8 LCP:    MagicNumber 0x3EA82025 (0x05063EA82025)
>May  3 19:25:10.329: Se2:8 LCP:    MRRU 1506 (0x110405E2)
>May  3 19:25:10.329: Se2:8 LCP:    EndpointDisc 4 Magic 
>(0x130B0424C084A65B44C123)
>May  3 19:25:10.329: Se2:8 LCP: O CONFACK [ACKrcvd] id 3 len 25
>May  3 19:25:10.329: Se2:8 LCP:    MagicNumber 0x3EA82025 (0x05063EA82025)
>May  3 19:25:10.329: Se2:8 LCP:    MRRU 1506 (0x110405E2)
>May  3 19:25:10.329: Se2:8 LCP:    EndpointDisc 4 Magic 
>(0x130B0424C084A65B44C123)
>May  3 19:25:10.329: Se2:8 LCP: State is Open
>May  3 19:25:10.329: Se2:8 PPP: Phase is AUTHENTICATING, by this end
>
>
>
>LNS
>---
>May  3 19:25:10.454: ppp972 PPP: Phase is ESTABLISHING
>May  3 19:25:10.454: ppp972 LCP: O CONFREQ [Closed] id 1 len 24
>May  3 19:25:10.454: ppp972 LCP:    AuthProto PAP (0x0304C023)
>May  3 19:25:10.454: ppp972 LCP:    MagicNumber 0x177FC929 (0x0506177FC929)
>May  3 19:25:10.454: ppp972 LCP:    MRRU 1524 (0x110405F4)
>May  3 19:25:10.454: ppp972 LCP:    EndpointDisc 1 mmp (0x1306016D6D70)
>May  3 19:25:10.502: ppp972 LCP: I CONFREQ [REQsent] id 6 len 25
>May  3 19:25:10.502: ppp972 LCP:    MagicNumber 0x3EA82025 (0x05063EA82025)
>May  3 19:25:10.502: ppp972 LCP:    MRRU 1506 (0x110405E2)
>May  3 19:25:10.502: ppp972 LCP:    EndpointDisc 4 Magic 
>(0x130B047EE40FA42EBF1911)
>May  3 19:25:10.502: ppp972 LCP: O CONFACK [REQsent] id 6 len 25
>May  3 19:25:10.506: ppp972 LCP:    MagicNumber 0x3EA82025 (0x05063EA82025)
>May  3 19:25:10.506: ppp972 LCP:    MRRU 1506 (0x110405E2)
>May  3 19:25:10.506: ppp972 LCP:    EndpointDisc 4 Magic 
>(0x130B047EE40FA42EBF1911)
>May  3 19:25:10.506: ppp972 LCP: I CONFACK [ACKsent] id 1 len 24
>May  3 19:25:10.506: ppp972 LCP:    AuthProto PAP (0x0304C023)
>May  3 19:25:10.506: ppp972 LCP:    MagicNumber 0x177FC929 (0x0506177FC929)
>May  3 19:25:10.506: ppp972 LCP:    MRRU 1524 (0x110405F4)
>May  3 19:25:10.506: ppp972 LCP:    EndpointDisc 1 mmp (0x1306016D6D70)
>May  3 19:25:10.506: ppp972 LCP: State is Open
>May  3 19:25:10.506: ppp972 PPP: Phase is AUTHENTICATING, by this end
>
>
>As you can see on the 1st case (LNS), we have the MRRU which gets CONFREJ 
>from the client, and i suppose this is the reason we can't establish the 
>multilink bundle.
>Any idea why?

The Client isn't keen about completely renegotiating LCP, I suppose.
Since the LAC has already REJ the client's request for MRRU (Multilink),
a subsequent attempt on the part of the LNS to utilize Multilink is
being denied by the client.

RFC 1661 3.4 says:

    The receipt of the LCP Configure-Request causes a return to the Link
    Establishment phase from the Network-Layer Protocol phase or
    Authentication phase.

"return to the Link Establishment phase" means that anything is possible
once again.  I suspect your ISDN TA is at fault.

mark



More information about the cisco-nas mailing list