DHCP Troubleshooting
This guide addresses structured steps for troubleshooting DHCP issues with CE devices. The DHCP protocol automatically assigns IP addresses and any other network configurations to devices, reducing the complexity associated with network management. All devices may fail to connect to the network only after DHCP fails to work, thus causing connectivity. This document focuses on CE device DHCP verification and potential trouble areas.
Troubleshooting Steps
Access the CE Terminal
Log into the CE device and gain root access:
sudo su -
Verify the Last Applied Configuration
Check the CE device's configuration to verify that the DHCP settings were accepted. This may be done by looking at the running configuration or checking a specific configuration file. The command will vary depending on the operating system of the CE device. For example, on some systems, you might check the output of a command like:
cat /tmp/last_config_response.json | jq
If your CE device can review the last config response, which something like the example you've provided accomplishes, then that should be checked.
Verify DHCPv2 Configuration (if applicable)
If your device implement DHCPv2, you are able to examine its actual settings:
cat last_config_response.json | jq '.service | '.dhcpV2
Example Response
root@Backup_node:/tmp# cat last_config_response.json | jq '.service | '.dh
cpV2
{
"eth3": {
"sharedNetworkName": "dhcpServer_eth3",
"subnet": "172.30.1.0/24",
"dnsServer": "172.30.1.1",
"defaultRouter": "172.30.1.1",
"dhcpRanges": [
{
"start": "172.30.1.101",
"stop": "172.30.1.200"
}
]
}
}
This command will extract and display the last configuration response using DHCPv2 configuration. Especially useful in debugging situations that may not be related to specific DHCPv2 settings.
Validate the Assigned IP Address
Confirm that the CE device has required an IP address in the correct DHCP Range. Use the appropriate command to display network interface information. A common command is:
ifconfig
Examine the output for the interface connected to the DHCP server and verify the assigned IP address and subnet mask. Compare the assigned IP address against the expected DHCP Pool range. For example. if the expected range is 172.10.2.51 to 172.10.2.101, the assigned IP should fall within these values.
System Log Inspection
Check the system log for any DHCP-related errors or warnings. The location and format of the system log varies on CE devices. Common commands include:
logread
Verify Network Connectivity:
Make sure the CE device has a valid IP address, subnet mask, and gateway. Use the following command to check network configuration:
uci show network
(Example Response):
root@Backup_node:~# uci show network
network.loopback=interface
network.loopback.device='lo'
network.loopback.proto='static'
network.loopback.ipaddr='127.0.0.1'
network.loopback.netmask='255.0.0.0'
network.@globals[0]=globals
network.@globals[0].packet_steering='1'
network.eth0=interface
network.eth0.device='eth0'
network.eth0.default_wan='1'
network.eth0.disabled='0'
network.eth0.proto='static'
network.eth0.ipaddr='172.20.10.8'
network.eth0.netmask='255.255.255.0'
network.eth0.dns='172.20.10.1'
network.eth3=interface
network.eth3.device='eth3'
network.eth3.proto='static'
network.eth3.netmask='255.255.255.0'
network.eth3.disabled='0'
network.eth3.ipaddr='172.30.1.1'
network.@rule[0]=rule
network.@rule[0].priority='901'
network.@rule[0].lookup='main'
network.wlm0=interface
network.wlm0.disabled='1'
network.wlm0.proto='3g'
network.wlm0.pppname='wlm0'
network.wlm0.device='ttyUSB0'
network.wlm0.apn='comgt'
network.wlm0.ipv6='0'
network.wlm0.delegate='0'
network.wlm0.metric='2'
network.wlm0.ip4table='2'
network.f85c71f21c3040bdb4abcd168fa8e900=route
network.f85c71f21c3040bdb4abcd168fa8e900.target='172.30.2.0'
network.f85c71f21c3040bdb4abcd168fa8e900.netmask='255.255.255.0'
network.f85c71f21c3040bdb4abcd168fa8e900.gateway='172.31.0.2'
network.f85c71f21c3040bdb4abcd168fa8e900.table='main'
network.f85c71f21c3040bdb4abcd168fa8e900.proto='static'
network.f85c71f21c3040bdb4abcd168fa8e900.metric='1'
network.f85c71f21c3040bdb4abcd168fa8e900.interface='br25'
network.1777530465de4eafada07376f1239abf=route
network.1777530465de4eafada07376f1239abf.target='172.30.1.0'
network.1777530465de4eafada07376f1239abf.netmask='255.255.255.0'
network.1777530465de4eafada07376f1239abf.gateway='172.31.0.1'
network.1777530465de4eafada07376f1239abf.table='main'
network.1777530465de4eafada07376f1239abf.proto='static'
network.1777530465de4eafada07376f1239abf.metric='1'
network.eth1=interface
network.eth1.proto='static'
network.eth1.device='eth1'
network.eth1.ipaddr='100.100.100.2'
network.eth1.netmask='255.255.255.0'
network.eth1.dns='172.20.10.1'
This output contains information about network settings such as IP address, netmask and DNS server for each interface pay particular attention to the interface used for WAN connectivity ( in this example, probably eth0). It must have a valid IP address and configured DNS server too. In any case, wrong network settings can block the access of the essential for accessing various networks. Ensure that the routes required to access the hiCloud server are properly configured.
Check hiCLOUDS Configuration:
The configuration on the CE device can be verified using the following command.
uci show hiclouds
(Example Response):
root@Backup_node:~# uci show hiclouds
hiclouds.globals=hiclouds
hiclouds.globals.hub='hub.hi-clouds.com'
hiclouds.globals.uri='deviceApi/getEndpointUrl'
hiclouds.globals.request_timeout='30'
hiclouds.globals.machine_id='33b01673-94a7-343e-b403-8c47cabac692'
hiclouds.globals.router_id='08:00:27:82:fc:73'
hiclouds.globals.endpoint='dev.hi-clouds.com'
hiclouds.globals.device_id='677e6da4ab30043a8492148a'
hiclouds.globals.auth_token='eyJhbGciOiJIUzUxMiJ9.eyJzdWIiOiI2NzdlNmRhNGFiMzAwNDNhODQ5MjE0OGE6OmNlOjozM2IwMTY3My05NGE3LTM0M2UtYjQwMy04YzQ3Y2FiYWM2OTI6OjA4OjAwOjI3OjgyOmZjOjczIiwiaWF0IjoxNzM4NjcxOTg5LCJleHAiOjE3Mzg2NzU1ODl9.JU0WBSCzpCbS8PTPypXoCvjka01IKcuKVm54YJnPjtt9jUZdF_5fTyraDc3oirSh67ZzKU7MbYo7Osy84AmoeA'
hiclouds.register=hiclouds
hiclouds.register.interval='30'
hiclouds.register.uri='api/deviceApi/v1/devices/register'
hiclouds.status=hiclouds
hiclouds.status.keepalive_interval='10'
hiclouds.status.status_interval='30'
hiclouds.status.uri='api/deviceApi/v1/devices'
hiclouds.config=hiclouds
hiclouds.config.uri='api/deviceApi/v1/devices'
hiclouds.config.revision='64bd463d-f6ae-4cfc-b89d-c4d74b63a382'
hiclouds.edge=hiclouds_edge
hiclouds.edge.type='CE'
hiclouds.hiclouds=hiclouds
hiclouds.hiclouds.version='22.03.5'
hiclouds.hiclouds.build='b75'
root@Backup_node:~# uci show hiclouds
hiclouds.globals=hiclouds
hiclouds.globals.hub='hub.hi-clouds.com'
hiclouds.globals.uri='deviceApi/getEndpointUrl'
hiclouds.globals.request_timeout='30'
hiclouds.globals.machine_id='33b01673-94a7-343e-b403-8c47cabac692'
hiclouds.globals.router_id='08:00:27:82:fc:73'
hiclouds.globals.endpoint='dev.hi-clouds.com'
hiclouds.globals.device_id='677e6da4ab30043a8492148a'
hiclouds.globals.auth_token='eyJhbGciOiJIUzUxMiJ9.eyJzdWIiOiI2NzdlNmRhNGFiMzAwNDNhODQ5MjE0OGE6OmNlOjozM2IwMTY3My05NGE3LTM0M2UtYjQwMy04YzQ3Y2FiYWM2OTI6OjA4OjAwOjI3OjgyOmZjOjczIiwiaWF0IjoxNzM4NjcxOTg5LCJleHAiOjE3Mzg2NzU1ODl9.JU0WBSCzpCbS8PTPypXoCvjka01IKcuKVm54YJnPjtt9jUZdF_5fTyraDc3oirSh67ZzKU7MbYo7Osy84AmoeA'
hiclouds.register=hiclouds
hiclouds.register.interval='30'
hiclouds.register.uri='api/deviceApi/v1/devices/register'
hiclouds.status=hiclouds
hiclouds.status.keepalive_interval='10'
hiclouds.status.status_interval='30'
hiclouds.status.uri='api/deviceApi/v1/devices'
hiclouds.config=hiclouds
hiclouds.config.uri='api/deviceApi/v1/devices'
hiclouds.config.revision='64bd463d-f6ae-4cfc-b89d-c4d74b63a382'
hiclouds.edge=hiclouds_edge
hiclouds.edge.type='CE'
hiclouds.hiclouds=hiclouds
hiclouds.hiclouds.version='22.03.5'
hiclouds.hiclouds.build='b75'
This output displays the hiCLOUDS-related configurations, such as the hub address, endpoint, deviceId, authToken, and the keepalive_interval. Check whether the hub and endpoint are correct and if the authToken is valid and non-expired. The keepalive_interval specifies how often the device is set to send Keepalive requests. A very short interval may cause unnecessary overloading of the network, while a too big interval may cause the device to be determined as offline in case connectivity is temporarily lost