Troubleshooting L2Tp - 3Com MSR 50 Series Configuration Manual

Troubleshooting L2TP

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[LNS-isp-aaa.net] ip pool 1 10.0.2.10 10.0.2.100
[LNS-isp-aaa.net] quit
# Create two virtual interface templates.
[LNS]interface virtual-template 1
[LNS-Virtual-Template1] ip address 1.1.2.2 255.255.255.0
[LNS-Virtual-Template1] remote address pool 1
[LNS-Virtual-Template1] ppp authentication-mode chap domain bbb.net
[LNS-Virtual-Template1] quit
[LNS] interface virtual-template 2
[LNS-Virtual-Template2] ip address 1.1.2.2 255.255.255.0
[LNS-Virtual-Template2] remote address pool 1
[LNS-Virtual-Template2] ppp authentication-mode chap domain aaa.net
[LNS-Virtual-Template2] quit
# Create two L2TP groups.
[LNS] l2tp-group 3
[LNS-l2tp3] tunnel authentication
[LNS-l2tp3] allow l2tp virtual-template 1 remote LAC domain aaa.net
[LNS-l2tp3] tunnel password simple 12345
[LNS-l2tp3] quit
[LNS] l2tp-group 4
[LNS-l2tp4] tunnel authentication
[LNS-l2tp4] allow l2tp virtual-template 2 remote LAC domain bbb.net
[LNS-l2tp4] tunnel password simple 12345
If the RADIUS authentication is required on the LNS, modifying the AAA
configurations as needed. For AAA configuration details, refer to "Configuring
AAA" on page 1761.
Complicated Network A security gateway can serve as an LAC and an LNS simultaneously. Additionally, it
Application has the ability to support more than one incoming call. Should there be enough
memory and physical lines, L2TP can receive and make multiple calls at the same
time. You can refer to the above examples for complicated network configuration.
Note that many L2TP applications rely on static routes to initiate connection
requests.
Troubleshooting L2TP
The VPN connection setup process is rather complicated. The following presents
an analysis of some common faults occurred in the process. Before
troubleshooting the VPN, make sure that the LAC and LNS are connected properly
across the public network.
Symptom 1:
Users cannot log in.
Analysis and solution:
Possible reasons for login failure are as follows:
1 Tunnel setup failure. In this case, it is possible that:
The address of the LNS is set incorrectly on the LAC.
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