Feature Requirements |
Series |
Models |
|---|---|---|
When a DHCPv4 client goes online with Option 82 information, if the path of the DHCPv4 relay return packet is different from that of the DHCPv4 request packet, you need to configure the backup DHCPv4 relay agent to parse Option 82 information to ignore the host name and forward the packet. In this case, the response packet does not contain Option 82 information in the DHCPv4 request packet. If a client needs to parse the Option 82 field in a DHCP Reply packet, the client may fail to go online. Use the following methods to ensure that the incoming and outgoing paths of packets are consistent: 1. Use Option 82's sub-option 5 to specify the network segment for address allocation, and set a different IP address for the giaddr field. The server must support sub-option 5. 2. Set a different source IP address for Option 82's sub-option 9. The route between two relay agents must be reachable, and the agents must be Huawei devices. 3. Configure a different source IP address. The server must use the source IP address of a request message as the destination IP address of a reply message. 4. Set different IP addresses of the same network segment for the giaddr field on the master and backup relay agents. The server must reserve two IP addresses in the address pool as gateway IP addresses for the master and backup relay agents. |
NetEngine 8000 F |
NetEngine 8000 F2A/NetEngine 8000 F1A |
When the UNR generated after a Layer 3 web user goes online from a BRAS conflicts with the ARP Vlink route, no Vlink route is generated. |
NetEngine 8000 F |
NetEngine 8000 F1A |
If the path of the DHCPv4 relay return packet is different from that of the DHCPv4 request packet, the relay service interface does not support address unnumbered. If the path for DHCPv4 relay return packets is different from that for DHCPv4 request packets and the address unnumbered function is enabled, the backup relay agent cannot forward packets after the master relay agent fails. As a result, service traffic is interrupted. It is recommended that static routes be configured for the IP addresses that users apply for. |
NetEngine 8000 F |
NetEngine 8000 F2A/NetEngine 8000 F1A |
One-to-many mapping between one MAC address and multiple sessions cannot be configured if an online user exists on the DHCP server. In addition, this function does not support multiple VRs. Log out the online user for the one-to-many mapping between one MAC address and multiple sessions to take effect. |
NetEngine 8000 F |
NetEngine 8000 F1A |
Addresses in the same address pool of the DHCP server cannot be allocated to DHCP clients that have the same MAC address but different VLANs. You are advised to enable one-to-many mapping between one MAC address and many sessions on the DHCP server. |
NetEngine 8000 F |
NetEngine 8000 F1A |
When the path of the DHCPv4 relay return packet is different from that of the DHCPv4 request packet and the Sub5 suboption of the Option 82 field is used to ensure consistent incoming and outgoing paths, the server must allocate addresses based on the Sub5 suboption of the Option 82 field. Otherwise, users cannot go online. Use the following methods: 1. Use Option 82 to ignore the host name matching check. The original request messages received by a relay agent cannot contain Option 82. 2. Set a different source IP address for Option 82's sub-option 9. The route between two relay agents must be reachable, and the agents must be Huawei devices. 3. Configure a different source IP address. The server must use the source IP address of a request message as the destination IP address of a reply message. 4. Set different IP addresses of the same network segment for the giaddr field on the master and backup relay agents. The server must reserve two IP addresses in the address pool as gateway IP addresses for the master and backup relay agents. |
NetEngine 8000 F |
NetEngine 8000 F2A/NetEngine 8000 F1A |
When the BAS gateway address is the same as the network-side DHCP relay gateway address, users with the same MAC address are not allowed to exist. You are advised to plan the network properly. |
NetEngine 8000 F |
NetEngine 8000 F2A/NetEngine 8000 F1A |
In a DHCPv4 relay dual-device hot backup scenario, to set different IP addresses of the same network segment for the giaddr field on the master and backup relay agents to ensure consistent incoming and outgoing paths, the DHCPv4 server must reserve two IP addresses in the address pool as gateway IP addresses for the master and backup relay agents.otherwise, Users may fail to obtain addresses. Use the following methods: 1. Use Option 82's sub-option 5 to specify the network segment for address allocation, and set a different IP address for the giaddr field. The server must support sub-option 5. 2. Use Option 82 to ignore the host name matching check. The original request messages received by a relay agent cannot contain Option 82. 3. Set a different source IP address for Option 82's sub-option 9. The route between two relay agents must be reachable, and the agents must be Huawei devices. 4. Configure a different source IP address. The server must use the source IP address of a request message as the destination IP address of a reply message. |
NetEngine 8000 F |
NetEngine 8000 F2A/NetEngine 8000 F1A |
The DHCP server function has been enabled using the dhcp server enable command on an interface if the interface needs to be used as a DHCP server, otherwise, Users may fail to obtain addresses: 1.If multiple interfaces need to be used as DHCP servers, for security purposes, you are advised to preferentially run the dhcp server enable command on the interfaces to enable the DHCP server function. If high security is not required, you run the dhcp server request-packet all-interface enable command in the system view to enable the DHCP server function for all interfaces. 2.If the DHCP server function is not enabled, a DHCP server does not process DHCP request messages. |
NetEngine 8000 F |
NetEngine 8000 F2A/NetEngine 8000 F1A |
In address pool allocation mode, when the DHCP server sends a FORCERENEW message to a specified user and reclaims the IP address of the user when the user does not respond, the IP address may be incorrectly reclaimed. For example, the FORCERENEW message fails to be sent or is lost or the RENEW message sent by the user is lost, because the link connected to the user is faulty or network congestion occurs. In scenarios where the DHCP server incorrectly reclaims the IP address of a user, if the user is still using the IP address, a conflict occurs when another user applies for this IP address. |
NetEngine 8000 F |
NetEngine 8000 F2A/NetEngine 8000 F1A |
If the path of DHCPv4 relay return packets is different from that of DHCPv4 request packets and the Sub9 suboption of Option 82 is used to ensure consistent incoming and outgoing paths, both the master and backup DHCPv4 relay agents must support the configuration of the Sub9 suboption of Option 82. Otherwise, users cannot go online. Use the following methods: 1. Use Option 82's sub-option 5 to specify the network segment for address allocation, and set a different IP address for the giaddr field. The server must support sub-option 5. 2. Use Option 82 to ignore the host name matching check. The original request messages received by a relay agent cannot contain Option 82. 3. Configure a different source IP address. The server must use the source IP address of a request message as the destination IP address of a reply message. 4. Set different IP addresses of the same network segment for the giaddr field on the master and backup relay agents. The server must reserve two IP addresses in the address pool as gateway IP addresses for the master and backup relay agents. |
NetEngine 8000 F |
NetEngine 8000 F2A/NetEngine 8000 F1A |
In a DHCPv6 relay dual-device hot backup scenario, the DHCPv6 relay service interface and VRRP interface must belong to the same main interface.The backup VRRP device does not process VRRP packets. If the DHCPv6 relay service interface and VRRP interface do not belong to the same main interface, DHCPv6 relay services cannot go online after the master device's VRRP interface associated with the relay service interface goes down. |
NetEngine 8000 F |
NetEngine 8000 F2A/NetEngine 8000 F1A |
After the DHCP server is enabled to allocate IP addresses based on Option 60, Option 60 cannot be changed during user migration. If Option 60 changes, users may fail to go online. |
NetEngine 8000 F |
NetEngine 8000 F2A/NetEngine 8000 F1A |
After a DHCP server is enabled to allocate IP addresses based on Option 60, a user fails to be migrated from address pool 1 to address pool 2 if the two address pools assign the same IP address to the user. Users go offline from address pool 1 and then go online from address pool 2, or the address segments assigned to address pool 1 and address pool 2 are different. |
NetEngine 8000 F |
NetEngine 8000 F2A/NetEngine 8000 F1A |
FORCERENEW messages sent by the DHCP server do not support authentication, and therefore the interconnected DHCP client is required not to authenticate FORCERENEW messages. If the DHCP client authenticates a FORCERENEW message, this message is discarded. |
NetEngine 8000 F |
NetEngine 8000 F2A/NetEngine 8000 F1A |
When the return packet path of the DHCPv4 relay agent is different from the request packet path and the source IP address of the DHCP packet is specified by the relay agent to ensure consistent incoming and outgoing paths, the server must use the source IP address of the request packet as the destination IP address of the response packet. Otherwise, users cannot go online. Use the following methods: 1. Use Option 82's sub-option 5 to specify the network segment for address allocation, and set a different IP address for the giaddr field. The server must support sub-option 5. 2. Use Option 82 to ignore the host name matching check. The original request messages received by a relay agent cannot contain Option 82. 3. Set a different source IP address for Option 82's sub-option 9. The route between two relay agents must be reachable, and the agents must be Huawei devices. 4. Set different IP addresses of the same network segment for the giaddr field on the master and backup relay agents. The server must reserve two IP addresses in the address pool as gateway IP addresses for the master and backup relay agents. |
NetEngine 8000 F |
NetEngine 8000 F2A/NetEngine 8000 F1A |