Troubleshooting: A STA Fails to Obtain an IP Address
Troubleshooting Roadmap
This document applies to WLAN devices of V200R006 and later versions.
- Check whether the link between a STA and the DHCP server is normal.
- Check whether the WLAN configuration is correct.
- Check whether the DHCP configuration is correct.
- Check whether address learning and strict address learning are configured.
- Check the mode of the wired interface.
Troubleshooting Procedure
- Check whether the link between the STA and server is normal.
- Check whether the interface is enabled to allow traffic from a specified VLAN to pass through and whether the VLAN configuration on the interface is incorrect.
- Check whether the gateway learns the MAC address entry of the STA.
- If the MAC address entry of the STA can be learned, the link between the STA and gateway is normal. If a DHCP relay agent is configured, go to 1.e. If no DHCP relay agent is configured, check whether the WLAN and DHCP configurations are correct.
<HUAWEI> display mac-address 14d6-4da7-3725 ------------------------------------------------------------------------------- MAC Address VLAN/VSI Learned-From Type ------------------------------------------------------------------------------- 14d6-4da7-3725 4094/- GE0/0/1 dynamic ------------------------------------------------------------------------------- Total items displayed = 1
- If the MAC address entry of the STA cannot be learned, the link between the STA and gateway is disconnected. In this case, go to 1.c and 1.d.
<HUAWEI> display mac-address 14d6-4da7-3725 ------------------------------------------------------------------------------- MAC Address VLAN/VSI Learned-From Type ------------------------------------------------------------------------------- ------------------------------------------------------------------------------- Total items displayed = 0
- If the MAC address entry of the STA can be learned, the link between the STA and gateway is normal. If a DHCP relay agent is configured, go to 1.e. If no DHCP relay agent is configured, check whether the WLAN and DHCP configurations are correct.
- In direct forwarding mode:
vap-profile name vap1 service-vlan vlan-id 1001 ssid-profile ssid1
- Check whether a service VLAN is created on the device between the AP and gateway. If no service VLAN is created, service VLAN packets fail to be forwarded. In this case, you need to create a service VLAN.
- Check whether the device between the AP and gateway allows packets from a service VLAN to pass through. If packets from a service VLAN are not allowed to pass through, service VLAN packets fail to be forwarded. In this case, you need to configure the device to allow packets from the server VLAN to pass through.
- In tunnel forwarding mode:
vap-profile name vap2 forward-mode tunnel service-vlan vlan-id 1001 ssid-profile ssid2
If the DHCP server is not an AC, the AC needs to be created and configured to transparently transmit service VLAN packets. Otherwise, the AC fails to forward service VLAN packets.
- Check whether the link between the DHCP relay agent and the DHCP server is normal.
interface Vlanif301 ip address 31.1.1.3 255.255.255.0 dhcp select relay dhcp relay server-ip 32.1.1.1
Use the IP address of the DHCP relay agent as the source IP address to ping the DHCP server.[HUAWEI] ping -a 31.1.1.3 32.1.1.1 PING 32.1.1.1: 56 data bytes, press CTRL_C to break Request time out Request time out Request time out Request time out Request time out --- 32.1.1.1 ping statistics --- 5 packet(s) transmitted 0 packet(s) received 100.00% packet loss- If the ping operation succeeds, the DHCP relay agent and DHCP server are routable to each other. Check whether the WLAN and DHCP configurations are correct.
- If the ping operation fails, the DHCP relay agent and DHCP server are unroutable to each other. In this case, check and add the route between the DHCP relay agent and DHCP server.
- If the local forwarding and bridging functions are configured, you are advised to disable ARP broadcast-to-unicast conversion.
[HUAWEI-wlan-traffic-prof-a] undo traffic-optimize bcmc unicast-send arp Warning: After configuration synchronization is enabled, an exception of the local or backup controller may lead to a configuration synchronization failure. [HUAWEI-wlan-traffic-prof-a] display this | include unicast-send arp undo traffic-optimize bcmc unicast-send arp
- Check whether the WLAN configuration is correct.
- In direct forwarding mode, check whether an AP's wired interface is configured as a DHCP snooping trusted interface.
Since V200R005, DHCP snooping is enabled on APs by default.
After the dhcp snooping enable command is configured on the interface connected to wireless users and the dhcp snooping trusted command is configured on the interface connected to the DHCP server, you can view the DHCP snooping configuration on the AP.
In direct forwarding mode, the correct configuration is as follows: <4862-76fb-cf20> display dhcp snooping configuration # dhcp snooping enable # interface GigabitEthernet0/0/0 dhcp snooping trusted # interface Wlan-Bss0 dhcp snooping enable # interface Wlan-Bss1 dhcp snooping enable # interface Wlan-Capwap0 dhcp snooping trusted #
In direct forwarding mode, if the undo dhcp trust port command is configured in an AP wired port profile and the profile is bound to the AP's uplink interface, the AP's uplink interface cannot be configured as the DHCP snooping trusted interface. As a result, DHCP request packets of STAs cannot be sent from the AP.
Run the command to check configuration about the undo dhcp trust port command. [HUAWEI] display current-configuration | include trust undo dhcp trust port Bind an AP wired port profile to the AP's uplink interface. wired-port-profile name wired1 undo dhcp trust port ap-group name group1 wired-port-profile wired1 gigabitethernet 0 In direct forwarding mode, the AP's uplink interface G0/0/0 is not configured as the DHCP snooping trusted interface. As a result, STAs cannot obtain IP addresses. <4862-76fb-cf20> display dhcp snooping configuration # dhcp snooping enable # interface Wlan-Bss0 dhcp snooping enable # interface Wlan-Bss1 dhcp snooping enable # interface Wlan-Capwap0 dhcp snooping trusted #
To solve this problem, run the undo dhcp trust port command on the AC or unbind the AP wired port profile from the AP's uplink interface.
- Check whether the service VLAN and management VLAN are the same.
You are advised to use different VLANs for the management VLAN and service VLAN. The management VLAN and service VLAN can be the same only when the AP is configured with the management-vlan command in direct forwarding mode and no PVID is configured for the management VLAN on the interface connecting the access switch to the AP. In other scenarios, if the management VLAN is the same as the service VLAN, STAs cannot obtain IP addresses.
- If a VLAN pool is configured as the service VLAN, ensure that the VLANs configured on the gateway are the same as the VLANs configured in the VLAN pool of the service VLAN.
- In direct forwarding mode, check whether an AP's wired interface is configured as a DHCP snooping trusted interface.
- Check whether the DHCP configuration is correct.
- Check whether DHCP snooping is configured on the access switch.
Wireless user mobility is high. A user does not send a DHCP Release packet to release the IP address upon going offline. As a result, the number of DHCP snooping binding entries reaches the maximum, and new user cannot obtain the IP address.
[S5720-36C-EI] display dhcp snooping DHCP snooping global running information : DHCPv4 snooping : Enable DHCPv6 snooping : Enable Static user max number : 256 Current static user number : 0 Dhcp user max number : 256 (default) Current dhcp user number : 256
By default, DHCP snooping is enabled on APs for wireless users. You are advised to delete the DHCP snooping configuration on the access switch. If a wired terminal is connected to the access switch and DHCP snooping must be enabled, you are advised to run the dhcp snooping enable no-user-binding command on the interface connected to an AP so that DHCP snooping binding entries are not generated for users connected to the interface.
- Check whether the DHCP server is configured correctly.
When the DHCP client and DHCP server are located on the same network segment, the DHCP server can assign an IP address to the DHCP client from an interface address pool.
[HUAWEI] interface Vlanif 10 [HUAWEI-vlanif10] display this # interface Vlanif10 ip address 192.168.1.1 255.255.255.0 dhcp select interface # return
When the DHCP client and DHCP server are located on the same network segment, the DHCP server can also assign an IP address to the DHCP client from the global address pool.
[HUAWEI] ip pool pool1 [HUAWEI-ip-pool-pool1] display this # ip pool pool1 gateway-list 192.168.1.1 network 192.168.1.0 mask 255.255.255.0 lease day 0 hour 8 minute 0 dns-list 114.114.114.114 # return [HUAWEI] interface Vlanif 10 [HUAWEI-vlanif10] display this # interface Vlanif10 ip address 192.168.1.1 255.255.255.0 dhcp select global #
When the DHCP client and DHCP server are located on different network segments, the DHCP server can assign an IP address to the DHCP client only from the global address pool.
[HUAWEI] ip pool pool1 [HUAWEI-ip-pool-pool1] display this # ip pool pool1 gateway-list 192.168.1.1 network 192.168.1.0 mask 255.255.255.0 lease day 0 hour 8 minute 0 dns-list 114.114.114.114 # return [HUAWEI] interface Vlanif 20 [HUAWEI-vlanif20] display this # interface Vlanif20 ip address 192.168.2.1 255.255.255.0 dhcp select global #
- Check whether the DHCP relay configuration is correct.
When the DHCP client and DHCP server are on different network segments, DHCP relay must be configured.
[HUAWEI] interface Vlanif 10 [HUAWEI-vlanif10] display this # interface Vlanif10 ip address 192.168.1.1 255.255.255.0 dhcp select relay//This command enables the DHCP relay function. If the function is disabled, enable it. dhcp relay server-ip 192.168.2.1//This command specifies an IP address for the DHCP server. If the IP address of a DHCP server is not specified or is incorrect, DHCP request packets cannot be forwarded to the DHCP server. As a result, the DHCP client cannot obtain the IP address. #
- Check whether there are available IP addresses in the address pool.
Run the display ip pool command to check whether there are available IP addresses in the address pool.
<HUAWEI> display ip pool interface Vlanif100 Pool-name: Vlanif100 Pool-No: 0 ... ------------------------------------------------------------------------------- Network section StartEndTotalUsed Idle(Expired) Conflict Disabled ------------------------------------------------------------------------------- 192.168.4.1192.168.4.2542540254(0)00 -------------------------------------------------------------------------------
If the value of Idle(Expired) is 0(0), no IP address is available for the server. In this case, you can extend the IP address range of the IP address pool or run the lease command (the dhcp server lease command is configured for the interface address pool) to reduce the IP address lease time. It is noted that the lease command takes effect only for new users. Online users need to go online again or use the new lease only after the lease is renewed successfully. Otherwise, the online users continue to use the old lease.
- Check whether the address pool information is cleared.
Run the display reset-reason command to check whether the server has been restarted.
<HUAWEI> display reset-reason The MPU frame[0] board[0]'s reset total 9, detailed information: --1. 2016-05-1714:48:41, Reset No.: 3 Reason: Reset by user command --2. 2016-05-1709:45:04, Reset No.: 2 Reason: Reset by user command --3. 2016-05-1609:26:42, Reset No.: 1 Reason: Reset forpower off
Run the display history-command command to check whether the address pool is cleared.
<HUAWEI> display history-command reset ip pool name 1 display history-command display reset-reason
If the DHCP server has been restarted or the address pool information has been cleared, the client information in the address pool may be lost. As a result, the DHCP server does not respond when a DHCP client goes online in two steps. In this case, you can set a fixed IP address for the client and then configure the client to obtain an IP address through DHCP, enabling the DHCP client to go online in four steps.
- Check whether DHCP snooping is configured on the access switch.
- Check whether address learning and strict address learning are configured.
Run the display this | include dhcp-strict command in the VAP profile view to check whether strict address learning is configured.
[HUAWEI-wlan-vap-prof-xy] display this | include dhcp-strict learn-client-address dhcp-strict
If strict address learning has been configured, run the undo learn-client-address dhcp-strict command to disable strict address learning.
[HUAWEI-wlan-vap-prof-xy] undo learn-client-address dhcp-strict Warning: After configuration synchronization is enabled, an exception of the local or backup controller may lead to a configuration synchronization failure. [HUAWEI-wlan-vap-prof-xy] display this # forward-mode tunnel service-vlan vlan-id 101 ssid-profile xy # return
- Check the mode of the wired interface.
When the central AP is connected to an RU and STAs cannot obtain IP addresses, check whether the root mode is configured in the wired port profile view of the interface connecting the central AP to the RU.
[HUAWEI-wlan-wired-port-a] display this | include mode mode root
If the root mode is configured, run the undo mode command to cancel the root mode and restore the default mode. The configuration takes effect after the AP is restarted.
[HUAWEI-wlan-wired-port-a] undo mode Warning: If the AP goes online through a wired port, the incorrect port mode configuration will cause the AP to go out of management . This fault can be recovered only by modifying the configuration on the AP. Continue? [Y/N]:y Warning: This action will take effect after resetting AP. Warning: After configuration synchronization is enabled, an exception of the local or backup controller may lead to a configuration synchronization failure. [HUAWEI-wlan-wired-port-a] display this | include mode
- Enable the STA-based station-trace function in the diagnostic view of the AC and check trace information about a DHCP server.# Enable the station-trace function.
[HUAWEI-diagnose] station-trace sta-mac 482c-a042-8227
The following table lists common trace information about a DHCP server.Trace Information
Description
[BTRACE][2015/12/28 17:17:51][DHCPPRO][dc00-07c4-023c]:Receive DHCP packet (srcif:Vlanif127 orgif:GigabitEthernet1/0/7 length:321 mflg:UC/BC).
[BTRACE][2015/12/28 17:17:51][DHCPPRO][dc00-07c4-023c]:ReceivesDHCP DISCOVERpacket from interface GigabitEthernet1/0/7.
[BTRACE][2015/12/28 17:17:51][DHCPPRO][dc00-07c4-023c]:Receive DHCP DISCOVER message.orgif:GE1/0/7 srcif:Vlanif127 L3if:Vlanif127 dstif:GE1/0/7 srcmac:dc00-07c4-023c dstmac:ffff-ffff-ffff vsi:- vlan:127/0 srcip:0.0.0.0 dstip:255.255.255.255 VPN:- src-port:68 dst-port:67 msgtype:BOOT-REQUEST dhcp msgtype:DHCP DISCOVER bflag:bc chaddr:dc00-07c4-023c ciaddr:0.0.0.0 reqip:0.0.0.0 giaddr:0.0.0.0 serverid:0.0.0.0 yiaddr:0.0.0.0 xid:0x7531
[BTRACE][2015/12/28 17:17:51][DHCPPRO][dc00-07c4-023c]:Find old soft l2fdb entry(mac:dc00-07c4-023c interface:GE1/0/7 vsi:65535 vlan:127/0 vt-mode:0)
[BTRACE][2015/12/28 17:17:51][DHCPPRO][dc00-07c4-023c]:Update packet option.(BitMap:0x0 Total length:321, IP:303, UDP:283)
A DHCP Discover packet is received. Whether the DHCP Offer packet is sent in broadcast (bc) or unicast (uc) mode depends on the bflag field.
[BTRACE][2015/12/28 17:17:51][DHCPPRO][dc00-07c4-023c]:Broadcast packet within VLAN 127(pri:0) succeed(Except:GE1/0/7)!
The DHCP Discover packet is sent in broadcast mode in the VLAN.
[BTRACE][2015/12/28 17:17:51][DHCPS][dc00-07c4-023c]:Receives DHCP DISCOVER message from interface Vlanif127.(chaddr=dc00-07c4-023c, ciaddr=0.0.0.0, giaddr=0.0.0.0, serverid=0.0.0.0, VPN=-, expect leasetime=0)
[BTRACE][2015/12/28 17:17:51][DHCPS][dc00-07c4-023c]:Gateway=192.168.127.1, mask=255.255.255.0.
[BTRACE][2015/12/28 17:17:51][DHCPS][dc00-07c4-023c]:Get pool Vlanif127 by gateway 192.168.127.1 and vrf 0.
[BTRACE][2015/12/28 17:17:51][DHCPS][dc00-07c4-023c]:Req static IP(poolname: Vlanif127, usermac:dc00-07c4-023c).
[BTRACE][2015/12/28 17:17:51][DHCPS][dc00-07c4-023c]:Get pool Vlanif127 by gateway 192.168.127.1 and vrf 0.
[BTRACE][2015/12/28 17:17:51][AM][dc00-07c4-023c]:Receive REQUEST message.(ClientId:UserType: DHCP, MAC: dc00-07c4-023c pool:22 vrf:0 expect-time:0)
[BTRACE][2015/12/28 17:17:51][AM][dc00-07c4-023c]:Try allocate expired ip for client id. (ClientId: UserType: DHCP, MAC: dc00-07c4-023c , pool:22)
[BTRACE][2015/12/28 17:17:51][AM][dc00-07c4-023c]:Offer ip 192.168.127.52 to cid(UserType: DHCP, MAC: dc00-07c4-023c) with lease time 86400 seconds.
[BTRACE][2015/12/28 17:17:51][DHCPS][dc00-07c4-023c]:Assigned ip address 192.168.127.52 for dc00-07c4-023c.
The DHCP server processes the DHCP Discover packet and allocates an IP address.
[BTRACE][2015/12/28 17:17:51][DHCPS][dc00-07c4-023c]:Sending ICMP ECHO to target ip address: 192.168.127.52.
The DHCP server sends an ICMP Echo Request packet before sending a DHCP Offer packet.
[BTRACE][2015/12/28 17:17:51][DHCPPRO][dc00-07c4-023c]:DHCP server protocol stack ends with stop.
The DHCP Discover packet is received and processed by the DHCP server. The displayed information is proper.
[BTRACE][2015/12/28 17:17:52][DHCPS][dc00-07c4-023c]:Sending ICMP ECHO to target ip address: 192.168.127.52.
[BTRACE][2015/12/28 17:17:52][DHCPS][dc00-07c4-023c]:ICMP timeout and send DHCP OFFER to client. (ciaddr=192.168.127.52, chaddr=dc00-07c4-023c).
The DHCP server sends a DHCP Offer packet after the ICMP probe is completed and no conflict is detected.
[BTRACE][2015/12/28 17:17:52][DHCPPRO][dc00-07c4-023c]:Receive DHCP packet (srcif:null orgif:null length:346 mflg:BC/BC).
[BTRACE][2015/12/28 17:17:52][DHCPPRO][dc00-07c4-023c]:Receive DHCP OFFER message.orgif:null srcif:null L3if:null dstif:GE1/0/7 srcmac:5439-dfcd-c668 dstmac:ffff-ffff-ffff vsi:- vlan:127/0 srcip:192.168.127.1 dstip:255.255.255.255 VPN:- src-port:67 dst-port:68 msgtype:BOOT-REPLY dhcp msgtype:DHCP OFFER bflag:bc chaddr:dc00-07c4-023c ciaddr:0.0.0.0 reqip:0.0.0.0 giaddr:0.0.0.0 serverid:192.168.127.1 yiaddr:192.168.127.52 xid:0x7531
[BTRACE][2015/12/28 17:17:52][DHCPPRO][dc00-07c4-023c]:L3IF IPv4 protocol status is down.
[BTRACE][2015/12/28 17:17:52][DHCPPRO][dc00-07c4-023c]:Update packet option.(BitMap:0x0 Total length:346, IP:328, UDP:308)
[BTRACE][2015/12/28 17:17:52][DHCPPRO][dc00-07c4-023c]:Broadcast packet within VLAN 127(pri:0) succeed!
The DHCP Offer packet is successfully sent in broadcast mode. (If the DHCP Offer packet is sent in unicast mode, the message Unicast packet to interface GE1/0/7 within VLAN 127(pri:0) succeed is displayed.)
[BTRACE][2015/12/28 17:17:52][DHCPPRO][dc00-07c4-023c]:Receive DHCP packet (srcif:Vlanif127 orgif:GigabitEthernet1/0/7 length:344 mflg:UC/BC).
[BTRACE][2015/12/28 17:17:52][DHCPPRO][dc00-07c4-023c]:Receives DHCP REQUEST packet from interface GigabitEthernet1/0/7.
[BTRACE][2015/12/28 17:17:52][DHCPPRO][dc00-07c4-023c]:Receive DHCP REQUEST message.orgif:GE1/0/7 srcif:Vlanif127 L3if:Vlanif127 dstif:GE1/0/7 srcmac:dc00-07c4-023c dstmac:ffff-ffff-ffff vsi:- vlan:127/0 srcip:0.0.0.0 dstip:255.255.255.255 VPN:- src-port:68 dst-port:67 msgtype:BOOT-REQUEST dhcp msgtype:DHCP REQUEST bflag:bc chaddr:dc00-07c4-023c ciaddr:0.0.0.0 reqip:192.168.127.52 giaddr:0.0.0.0 serverid:192.168.127.1 yiaddr:0.0.0.0 xid:0x7531
[BTRACE][2015/12/28 17:17:52][DHCPPRO][dc00-07c4-023c]:Find old soft l2fdb entry(mac:dc00-07c4-023c interface:GE1/0/7 vsi:65535 vlan:127/0 vt-mode:0)
[BTRACE][2015/12/28 17:17:52][DHCPPRO][dc00-07c4-023c]:Update packet option.(BitMap:0x0 Total length:344, IP:326, UDP:306)
A DHCP Request packet is received. Whether the DHCP ACK packet is sent in broadcast (bc) or unicast (uc) mode depends on the bflag field.
[BTRACE][2015/12/28 17:17:52][DHCPPRO][dc00-07c4-023c]:Broadcast packet within VLAN 127(pri:0) succeed(Except:GE1/0/7)!
The DHCP Request packet is sent in broadcast mode in the VLAN.
[BTRACE][2015/12/28 17:17:52][DHCPS][dc00-07c4-023c]:Receives DHCP REQUEST message from interface Vlanif127.(chaddr=dc00-07c4-023c, ciaddr=0.0.0.0, giaddr=0.0.0.0, serverid=192.168.127.1, reqip=192.168.127.52, VPN=-, expect leasetime=0)
[BTRACE][2015/12/28 17:17:52][DHCPS][dc00-07c4-023c]:Process request_of_selecting message.
[BTRACE][2015/12/28 17:17:52][DHCPS][dc00-07c4-023c]:Gateway=192.168.127.1, mask=255.255.255.0.
[BTRACE][2015/12/28 17:17:52][DHCPS][dc00-07c4-023c]:Select gateway 192.168.127.1 and mask 255.255.255.0 by request address 192.168.127.52.
[BTRACE][2015/12/28 17:17:52][AM][dc00-07c4-023c]:Receive REQUEST message.(ClientId:UserType: DHCP, MAC: dc00-07c4-023c pool:22 vrf:0 expect-ip:192.168.127.52 expect-time:0)
[BTRACE][2015/12/28 17:17:52][AM][dc00-07c4-023c]:Try allocate leased ip for client.(ClientId : UserType: DHCP, MAC: dc00-07c4-023c, pool:22, Section:256)
[BTRACE][2015/12/28 17:17:52][AM][dc00-07c4-023c]:Get gateway and mask failed. (pool:22)
[BTRACE][2015/12/28 17:17:52][AM][dc00-07c4-023c]:Offer ip 192.168.127.52 to cid UserType: DHCP, MAC: dc00-07c4-023c.
[BTRACE][2015/12/28 17:17:52][DHCPS][dc00-07c4-023c]:DHCPS process Request. (ulServerAddr=192.168.127.1, ulMask=255.255.255.0)
[BTRACE][2015/12/28 17:17:52][DHCPS][dc00-07c4-023c]:Send DHCP ACK packet.(Chaddr=dc00-07c4-023c, Offer IP=192.168.127.52).
The DHCP server processes the DHCP Request packet and then sends a DHCP ACK packet.
[BTRACE][2015/12/28 17:17:52][DHCPPRO][dc00-07c4-023c]:DHCP server protocol stack ends with stop.
The DHCP Request packet is received and processed by the DHCP server. The displayed information is proper.
[BTRACE][2015/12/28 17:17:52][DHCPPRO][dc00-07c4-023c]:Receive DHCP packet (srcif:null orgif:null length:346 mflg:BC/BC).
[BTRACE][2015/12/28 17:17:52][DHCPPRO][dc00-07c4-023c]:Receive DHCP ACK message.orgif:null srcif:null L3if:null dstif:GE1/0/7 srcmac:5439-dfcd-c668 dstmac:ffff-ffff-ffff vsi:- vlan:127/0 srcip:192.168.127.1 dstip:255.255.255.255 VPN:- src-port:67 dst-port:68 msgtype:BOOT-REPLY dhcp msgtype:DHCP ACK bflag:bc chaddr:dc00-07c4-023c ciaddr:0.0.0.0 reqip:0.0.0.0 giaddr:0.0.0.0 serverid:192.168.127.1 yiaddr:192.168.127.52 xid:0x7531
[BTRACE][2015/12/28 17:17:52][DHCPPRO][dc00-07c4-023c]:L3IF IPv4 protocol status is down.
[BTRACE][2015/12/28 17:17:52][DHCPPRO][dc00-07c4-023c]:Update packet option.(BitMap:0x0 Total length:346, IP:328, UDP:308)
[BTRACE][2015/12/28 17:17:52][DHCPPRO][dc00-07c4-023c]:Broadcast packet within VLAN 127(pri:0) succeed!
The DHCP ACK packet is successfully sent in broadcast mode. (If the DHCP ACK packet is sent in unicast mode, the message Unicast packet to interface GE1/0/7 within VLAN 127(pri:0) succeed is displayed.)
