1. The AP of the same model is already online, so it is not a version problem;
2. Check whether the license is sufficient, we find that the license is sufficient.
Total number of APs: 4058
Total number of connected APs: 3880
Total number of connected manual APs: 3873
Total number of connected auto APs: 7
Total number of connected common APs: 231
Total number of connected WTUs: 3487
Total number of inside APs: 0
Maximum supported APs: 4096
Remaining APs: 378
Total AP licenses: 1536
Local AP licenses: 1536
Server AP licenses: 0
Remaining Local AP licenses: 433.25
Sync AP licenses: 0
State : I = Idle, J = Join, JA = JoinAck, IL = ImageLoad
C = Config, DC = DataCheck, R = Run, M = Master, B = Backup
3. After checking the communication between AC and the new AP IP, we found that AP did not get the address normally.
4.Check the address pool on AC and find that the address pool has been allocated, but there are not that many AP"s.Looking at the pool of conflicting addresses, you find a large number of conflicting addresses.
5. Check the arp information of the access switch and find that one MAC corresponds to more than one IP, corresponding to the address in the conflicting address pool.
Type: S-Static D-Dynamic
IP Address MAC Address VLAN ID Interface Aging Type
10.100.44.173 80f6-2e4e-9c60 2110 GE1/0/2 17 D
10.100.44.252 80f6-2e4e-9c60 2110 GE1/0/2 17 D
10.100.45.50 80f6-2e4e-9c60 2110 GE1/0/2 17 D
10.100.45.106 80f6-2e4e-9c60 2110 GE1/0/2 17 D
10.100.36.170 80f6-2e4c-4a00 2110 GE1/0/6 17 D
10.100.44.190 80f6-2e4c-4a00 2110 GE1/0/6 17 D
10.100.44.254 80f6-2e4c-4a00 2110 GE1/0/6 17 D
10.100.45.44 80f6-2e4c-4a00 2110 GE1/0/6 17 D
10.100.44.182 70ba-efca-1f20 2110 GE1/0/8 17 D
10.100.44.198 70ba-efca-1f20 2110 GE1/0/8 17 D
10.100.45.22 70ba-efca-1f20 2110 GE1/0/8 17 D
10.100.45.32 70ba-efca-1f20 2110 GE1/0/8 17 D
10.100.45.52 70ba-efca-1f20 2110 GE1/0/8 17 D
10.100.45.107 70ba-efca-1f20 2110 GE1/0/8 17 D
6.Analyze the principle of DHCP
(1) The client broadcasts a DHCP-DISCOVER message to locate a DHCP server.
(2) Each DHCP server offers configuration parameters such as an IP address to the client in a
DHCP-OFFER message. The sending mode of the DHCP-OFFER is determined by the flag
field in the DHCP-DISCOVER message. For more information, see "DHCP message format."
(3) If the client receives multiple offers, it accepts the first received offer, and broadcasts it in a
DHCP-REQUEST message to formally request the IP address. (IP addresses offered by other
DHCP servers can be assigned to other clients.)
(4) All DHCP servers receive the DHCP-REQUEST message. However, only the server selected by the client does one of the following operations:
Returns a DHCP-ACK message to confirm that the IP address has been allocated to the
Returns a DHCP-NAK message to deny the IP address allocation.
After receiving the DHCP-ACK message, the client verifies the following details before using the
assigned IP address:
• The assigned IP address is not in use. To verify this, the client broadcasts a gratuitous ARP
packet. The assigned IP address is not in use if no response is received within the specified
• The assigned IP address is not on the same subnet as any IP address in use on the client.
Otherwise, the client sends a DHCP-DECLINE message to the server to request an IP address
7. There should be a loop below, which causes the terminal to repeatedly apply for the address, leading to the exhaustion of the address pool, and then the newly added AP cannot obtain the address, leading to the failure to go online.
Clear the conflict address pool, remove the loop and AP will normally get the address.