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NE40E BARS NAT issue

Latest reply: Jun 30, 2018 03:02:36 1104 1 0 0 0
Issue Description

In a nat instance , already add 8120 address for private user to access Internet .

but only 7170 users can access Internet .other user cannot access .

When executed command "display aaa online-fail-record " get this error :Add nat user data fail(Port PreAlloc Fail)

transparent.gif Handling Process

Check nat instance configuration ,we find port-range is 8192 .but this command just for port pre-allocation.

And about the facing error :Add nat user data fail(Port PreAlloc Fail) ,because public address port not enough for user online.

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transparent.gif Root Cause

Public address port not enough for user online.

transparent.gif Solution

about other  users cannot online ,there are two ways to solve it :


1、  customer need extension the public address pool  for the online-fail nat instance

2、  modify port-range value , please refer below , need online user offline release resource , then new user can online .


         [HUAWEI] nat instance 1

[HUAWEI-nat-instance-1] undo port-range

[HUAWEI-nat-instance-1] port-range 4096



[HUAWEI-aaa]cut access-user domain domain-name   /// must kick off user offline , this configuration can work .

Or if not cut users offline , must wait user online again , this configuration can work .

  • x
  • convention:

Created Jun 30, 2018 03:02:36

Actully,The system supports port allocation modes: dynamic port allocation, static port pre-allocation, semi-dynamic port pre-allocation, and per-port allocation.
•Dynamic port allocation mode: By default, the system dynamically allocates ports to users. In this mode, the number of ports allocated to users is not limited.
Static port pre-allocation mode: This mode is supported when extended-port-range extended-port-range or extended-times extended-times is not specified. After the port-range command is run in the NAT instance view, the system pre-allocates a port range to private network users to perform NAT. Running the port-range command in the NAT instance view indicates that this NAT instance uses the static port pre-allocation mode. The port-range command also specifies the size of a port range. The start and end port numbers are automatically generated. (you configured)
•Semi-dynamic port pre-allocation mode: This mode is supported when both extended-port-range extended-port-range and extended-times extended-times are specified. In this mode, the system pre-allocates a port range to private network users. The system uses ports in this port range to perform NAT. When all ports in this port range are allocated, a pre-set range of ports are assigned to users. The number of times that the port range can be extended is configurable to determine the maximum number of assignable ports. If a newly assigned port range is no longer used, this port range can be reclaimed and allocated to other users.
•To configure the per-port allocation mode, run the port-single enable command. Per-port allocation is a dynamic port allocation mode. Specifically, a port, instead of a port segment, is allocated each time a flow table entry is created. Such a mode features the highest port usage of a public IP address and therefore is used when few IPv4 public IP addresses exist or when few ports are required for services.
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  • x
  • convention:


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