allow-address-change

Function

The allow-address-change command configures the device to use the changed source IP address of packets replied by the LNS as the destination IP address of packets to be sent during tunnel establishment or hello detection process.

The undo allow-address-change command restores the default configuration.

By default, the device does not respond to the LNS's source IP address change during tunnel establishment or hello detection process.

This command is supported only on the NetEngine 8000 F1A.

Format

allow-address-change { setup-only | always }

undo allow-address-change [ setup-only | always ]

Parameters

Parameter	Description	Value
setup-only	Uses the changed source IP address of SCCRP packets replied by the LNS as the destination IP address of packets for subsequent tunnel negotiation.	-
always	Uses the changed source IP address of SCCRP, Hello, or ZLB packets replied by the LNS as the destination IP address of packets for subsequent tunnel negotiation or detection.	-

Parameter

Description

Value

setup-only

Uses the changed source IP address of SCCRP packets replied by the LNS as the destination IP address of packets for subsequent tunnel negotiation.

always

Uses the changed source IP address of SCCRP, Hello, or ZLB packets replied by the LNS as the destination IP address of packets for subsequent tunnel negotiation or detection.

Views

L2TP group view

Default Level

2: Configuration level

Task Name and Operations

Task Name	Operations
l2tp	write

Usage Guidelines

Usage Scenario

When the device functions as an LAC to communicate with an LNS of another vendor, if source IP addresses of packets sent from the LNS always change, and the destination IP address of packets sent from the LAC is different from that configured on the LNS, tunnel establishment fails. To prevent this problem, run the allow-address-change command.

If the source IP addresses change on the LNS only in tunnel establishment phase, run the allow-address-change setup-only command in the L2TP group view of the device.

If the source IP addresses change on the LNS in both the tunnel establishment and hello detection phases, run the allow-address-change always command in the L2TP group view of the device.

Configuration Impact

After the allow-address-change command is run, the device uses the source IP address of packets replied by the LNS as the destination IP address of packets to be sent for tunnel negotiation and detection.

In the display l2tp tunnel command output, the Remote Address field indicates the LNS IP address configured in the L2TP group or delivered by the RADIUS server; the Lns-reply Address field indicates the source IP address of SCCRP packets replied by the LNS.

Example

# Configure using the changed source IP address of packets replied by the LNS as the destination IP address of packets to be sent during tunnel establishment process.

<HUAWEI> system-view
[~HUAWEI] l2tp-group lac1
[~HUAWEI-l2tp-lac1] allow-address-change setup-only