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DHCP client wont get ip from C9800 LC

AliDoskii
Level 1
Level 1

 

AliDoskii_1-1732878479313.png

Hello Cisco Community,

Hope everyone is well.

Recently i am facing difficulty with implementing my wireless network.
i have installed wireless access point and all of them successfully appearing in my wireless controller dashboard, WLAN created for them and SSID is working fine, i could see and connect to my SSID without problem.

The only problem that i have is, my wireless client cannot get ip address from DHCP.

I have made VLAN 50 to be relay as well but still no chance, whereas access point is getting ip address from DHCP without any problem.

can someone please help me with that?
Thanks in advance,
AliDoski

AliDoski
1 Accepted Solution

Accepted Solutions

Then create another vlan, for example vlan 60 layer2 only on the WLC and make layer3 on the core. Add this new vlan to your WLAN and use it for clients. Leave the vlan 50 for management.

 

FlavioMiranda_0-1732906127626.png

 

 

View solution in original post

29 Replies 29

marce1000
VIP
VIP

 

 - Start with a checkup of the C9800 configuration using the CLI command show  tech wireless and feed the output from
    that into Wireless Config Analyzer
                             (do not use a simple show tech as input for WirelessAnalyzer ; use the full command in green)

   - Further engage in full client debugging according to https://logadvisor.cisco.com/logadvisor/wireless/9800/9800ClientConnectivity , these debugs can be analyzed with Wireless Debug Analyzer

  -  - Outputs from the commands mentioned in https://www.cisco.com/c/en/us/support/docs/wireless/catalyst-9800-series-wireless-controllers/217738-monitor-catalyst-9800-kpis-key-performa.html#anc5 can also be useful , especially when changes are made to the configuration

 - Use this architecture for DHCP https://www.cisco.com/c/en/us/td/docs/wireless/controller/9800/technical-reference/c9800-best-practices.html#DHCPbridgingandDHCPrelay

 - Look into the controller software version , go for 17.12.3 , especially if you are currently on an older version , 

 M.



-- Each morning when I wake up and look into the mirror I always say ' Why am I so brilliant ? '
    When the mirror will then always repond to me with ' The only thing that exceeds your brilliance is your beauty! '

@AliDoskii 

Assuming you using Local mode and not flexconnect. Can you ping the WLC IP address on vlan 50 from the DHCP server?

Or, can you ping the DHCP server from the WLC?

@Flavio Miranda 
DHCP server is same as default gateway, yes i could ping without issue.
and yes, all my APs are operating in local mode as shown.

AliDoskii_0-1732879845304.png

AliDoskii_1-1732879887403.png

 

AP are getting IP from DHCP with no issue:

AliDoskii_3-1732880192120.png

 

 

 

AliDoski

Wlan is mapped to vlan 50 on WLC?

How can i verify this?

AliDoski

show wlan summary

AliDoskii_0-1732883985035.png

Here is my WLAN config :
WLC(config-wlan)#do show run wlan
!
aaa attribute list wlan_lobby_access
policy-map AutoQos-4.0-wlan-Port-Output-Policy
class AutoQos-4.0-Output-CAPWAP-C-Class
priority level 1
class AutoQos-4.0-Output-Voice-Class
priority level 2
class class-default
service-policy output AutoQos-4.0-wlan-Port-Output-Policy
service-policy output AutoQos-4.0-wlan-Port-Output-Policy
service-policy output AutoQos-4.0-wlan-Port-Output-Policy
service-policy output AutoQos-4.0-wlan-Port-Output-Policy
service-policy output AutoQos-4.0-wlan-Port-Output-Policy
wlan Radisson policy Radisson
wlan Radisson 1 Radisson-Starlink
security wpa psk set-key ascii 0 ciscocisco
no security wpa akm dot1x
security wpa akm psk
security pmf optional
no shutdown
!

AliDoski

I was expecting a different output from this command.  Take a look on this video and make sure you went through all the steps. On this video the dude show how to map WLAN to VLAN and setup DHCP server on the WLAN.

https://www.youtube.com/watch?v=5FpYS_rphik

 

This Video recording is the second in the series of the Cisco Catalyst 9800 series configuration based on the Cisco Cloud platform. ThisBasic WLAN Setup recordings will explain how to use "Basic setup" on the Cat9800 controller. This Video recording will be followed up by four additional episodes

i believe i made a mistake at the initial config of my controller in policy section of WLAN creation i chose default VLAN instead of VLAN 50.

AliDoski

That might be something like this. The WLC is not placing the DHCP request on the right vlan. Check the DHCP server is rihgt configured on the WLAN also.

I have changed WLAN VLAN to 50 as previously was default 1.
and  i have configured server DHCP in policy and put my server DHCP 10.10.50.1 and removed ip helper address under vlan 50 as they are all in some subnet.

but still my wireless users cannot get ip address from dhcp.

AliDoskii_0-1732893101672.pngAliDoskii_1-1732893143342.png

 

AliDoskii_2-1732893305464.png

 

 



AliDoski

 

 - May  I still remind you to execute the WirelessAnalyzer procedure when making configuration changes on the controller :
   using the CLI command show  tech wireless and feed the output from
    that into Wireless Config Analyzer
                             (do not use a simple show tech as input for WirelessAnalyzer ; use the full command in green)

   Consider mandatory after configuring has been done !!

 M.



-- Each morning when I wake up and look into the mirror I always say ' Why am I so brilliant ? '
    When the mirror will then always repond to me with ' The only thing that exceeds your brilliance is your beauty! '

sorry i missed first comment.
here is tech support file attached

AliDoski

 

   - I found no fundamental errors in WLCRESULTS.xlsx , you should debug a client which gets no ip address :
    according to https://logadvisor.cisco.com/logadvisor/wireless/9800/9800ClientConnectivity , these debugs can then be analyzed with Wireless Debug Analyzer

  M.



-- Each morning when I wake up and look into the mirror I always say ' Why am I so brilliant ? '
    When the mirror will then always repond to me with ' The only thing that exceeds your brilliance is your beauty! '
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