Why is the DHCP configuration lost on an AR after a while


If Auto-Config is enabled, the AR will periodically clear all DHCP configurations, causing DHCP configuration loss. To solve the problem, perform the following steps:
1. Run the undo autoconfig enable command on the AR to disable Auto-Config.
2. Wait for 4 or 5 minutes and run the display autoconfig-status command to check the Auto-Config status. If the value of Running is NO, the Auto-Config function has been disabled.
3. Perform the configuration and run the save command.

Other related questions:
Will the configuration of an AR router be lost after the SRU is replaced
The configuration file of an AR router is stored in the storage medium of the SRU. For a single-control router, the configuration of a router is subject to the new SRU. For a dual-control router, the router automatically copies the configuration file to the standby SRU after the active SRU is switched over to the standby SRU.

How do I solve the DHCP configuration loss problem after device restart

After the device restarts, there is a low probability that the DHCP configuration is lost.

Auto-Config is enabled by default. About two and a half minutes after the device restarts, the Auto-Config module checks whether the configuration file exists and determine whether the Auto-Config process is executed. If the save command is used at this time, files conflict. As a result, the Auto-Config module determines that the configuration file does not exist, and incorrectly executes the Auto-Config process. In this case, information about option fields or intermediate file required for executing the Auto-Config process is not configured on the DHCP server. Consequently, the Auto-Config process is suspended, and the DHCP configuration (including the configuration during configuration recovery and the Auto-Config process) is deleted.

After the device restarts, run the undo autoconfig enable command in the system view to disable Auto-Config.

The packets sent to an IP address in a configured NAT address pool are discarded
Q: The packets sent to an IP address in a configured NAT address pool are discarded. You can run the ip route-static command to configure a static route to the IP address. The default priority of a static route is 60, which is higher than that of the UNR. This prevents packets sent to an IP address in the address pool from being discarded. The causes are as follows: After a NAT address pool is configured on an interface, a 32-bit local user network route (UNR) is automatically generated, and its priority is 64. When a packet to be sent to an IP address in the address pool passes the router, it matches the 32-bit local UNR and is sent to the protocol stack. However, the router cannot forward the packet because it does not have the protocol stack of the IP address. The packet is discarded. Therefore, you need to configure a static route with the default priority higher than that of the UNR.

Packets are lost after A2A VPN is deployed on the AR
After A2A VPN is deployed, if the size of A2A VPN packets exceeds the interface MTU and the DF flag is not set to 0, the A2A VPN packets are discarded, causing packet loss. In this case, run the ipsec df-bit clear command to allow A2A VPN packets to be fragmented.

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