L2TPV3 tunnel id range different on IOS 12.2(33)SRE/12.4(15)T

[Takeo Tung]

I was found the different IOS support L2TPV3 tunnel ID, like 12.2(33)SRE is support 32bit, 12.4(15)T is support 16bit.

so the 12.2(33)SRE can't xconnect/l2tpv3 to 12.4(15)T.

I found the 12.2(33)SRE Local Tunnel ID is over 65535, how about reduce it less 65535? or some other suggest to xconnect/l2tpv3 on different IOS?

bcoz using same IOS series is normal. like 12.4T and 12.4T / 12.2SRE and 12.2SRE

some result is following.

12.4(15)T:

xxxx#sh xconnect interface gigabitEthernet 0/2.209 detail
Legend: XC ST=Xconnect State, S1=Segment1 State, S2=Segment2 State
UP=Up, DN=Down, AD=Admin Down, IA=Inactive, NH=No Hardware
XC ST  Segment 1                         S1 Segment 2                         S2
------+---------------------------------+--+---------------------------------+--
DN     ac   Gi0/2.209 209(Eth VLAN)      UP l2tp 152.xxx.xxx.120:500           DN
            Interworking: none                   Session ID: 15758
                                                 Tunnel ID: 60524
                                                 Protocol State: DOWN
                                                 Remote Circuit State: DOWN
                                                 pw-class: vlan-xconnect

xxxx#sh l2tun tun

L2TP Tunnel Information Total tunnels 1 sessions 1

LocID RemID Remote Name   State  Remote Address  Port  Sessions L2TP Class/
                                                                VPDN Group
50018 55075 xxxx     est    152.xxx.xxx.120  0     1        l2tp_default_cl

xxxx#sh l2tun session

L2TP Session Information Total tunnels 1 sessions 1

LocID      RemID      TunID      Username, Intf/      State  Last Chg Uniq ID  
                                 Vcid, Circuit                                 
15770      0          14624      500, Gi0/2.209:209   wicrp  00:00:26 40

12.2(33)SRE:

xxxx#sh xconnect interface g0/3.209 detail
Legend:    XC ST=Xconnect State  S1=Segment1 State  S2=Segment2 State
  UP=Up       DN=Down            AD=Admin Down      IA=Inactive
  SB=Standby  HS=Hot Standby     RV=Recovering      NH=No Hardware

XC ST  Segment 1                         S1 Segment 2                         S2
------+---------------------------------+--+---------------------------------+--
DN     ac   Gi0/3.209:209(Eth VLAN)      UP l2tp 202.xxx.xxx.12:500            DN
            Interworking: none                   Session ID: 0                 
                                                 Tunnel ID: 0                  
                                                 Protocol State: DOWN          
                                                 Remote Circuit State: DOWN    
                                                 pw-class: vlan-xconnect

xxxxx#show l2tun      

L2TP Tunnel and Session Information Total tunnels 1 sessions 0

LocTunID   RemTunID   Remote Name   State  Remote Address  Sessn L2TP Class/
                                                           Count VPDN Group
384183004  19877      xxxx wscccn 202.xxx.xxx.12   0     l2tp_default_cl
xxxx#show l2tun session

L2TP Session Information Total tunnels 1 sessions 0

[hbruyere]

Hello,

The Tunnel ID in the show xconnect command correspond to the Control Connection ID in the l2tpv3 RFC, and has local significance only.

Each side of the session has his own 32 bit session id. The value does not need to match.

http://tools.ietf.org/search/rfc3931#section-3.2.1

   The Control Connection ID field contains the identifier for the
   control connection.  L2TP control connections are named by
   identifiers that have local significance only.  That is, the same
   control connection will be given unique Control Connection IDs by
   each LCCE from within each endpoint's own Control Connection ID
   number space.  As such, the Control Connection ID in each message is
   that of the intended recipient, not the sender.  Non-zero Control
   Connection IDs are selected and exchanged as Assigned Control
   Connection ID AVPs during the creation of a control connection.

So if the l2tpv3 tunnel does not come up, that must be for another reason.

Regards,

Herve

[vineetccnp]

I have the same problem while forming L2dTP tunnel between ciso 1941 running 15.2M and cisco 3845 running 12.4.

But when i replaced 1941 with cisco 2800 with ios 12.4, l2tp was up with the same configuration.

Please help urgently