topic Re: Client cannot get IP from ex DHCP in Wireless

Client cannot get IP from ex DHCP

beta_admin66 — Mon, 23 Aug 2021 14:59:06 GMT

Hello,

client can not get an IP address from an external DHCP server.

Here is the debug on the WLC:

*DHCP Socket Task: <date/time>: [SA] <mac-address> DHCP received op BOOTREQUEST (1) (len xxx vlan xxx, port 8, encap 0xec03, xid 0xc96dd9c4)
*DHCP Socket Task: <date/time> : [SA] <mac-address> DHCP (encap type 0xec03) mstype 0ff:ff:ff:ff:ff:ff
*DHCP Socket Task:<date/time>: [SA] <mac-address> DHCP processing DHCP DISCOVER (1)
*DHCP Socket Task: <date/time> [SA] <mac-address> DHCP op: BOOTREQUEST, htype: Ethernet, hlen: 6, hops: 0
*DHCP Socket Task: <date/time>: [SA] <mac-address> DHCP xid: 0xc4d96dc9 (3302583753), secs: 0, flags: 0
*DHCP Socket Task: <date/time>: [SA] <mac-address> DHCP chaddr: <mac-address>
*DHCP Socket Task: <date/time>: [SA] <mac-address> DHCP ciaddr: 0.0.0.0, yiaddr: 0.0.0.0
*DHCP Socket Task: <date/time>: [SA] <mac-address> DHCP siaddr: 0.0.0.0, giaddr: 0.0.0.0
*DHCP Socket Task: <date/time>: [SA] <mac-address> DHCP received op BOOTREQUEST (1) (len 308,vlan 128, port 8, encap 0xec03, xid 0xc96dd9c4)

IP helper address is configured on the WLAN VLAN.

Is it an access point issue?

Thank you very much.

Re: Client cannot get IP from ex DHCP

Leo Laohoo — Mon, 23 Aug 2021 22:47:46 GMT

@beta_admin66 wrote:

client can not get an IP address from an external DHCP server.

IP helper address is configured on the WLAN VLAN.

Is this only affecting ONE wireless client or a lot?

Re: Client cannot get IP from ex DHCP

beta_admin66 — Tue, 24 Aug 2021 06:30:07 GMT

All wireless clients that want to connect to a specific access point are affected.

Re: Client cannot get IP from ex DHCP

Mark Elsen — Tue, 24 Aug 2021 07:16:13 GMT

- Try rebooting the particular access point, check if that can help.

Re: Client cannot get IP from ex DHCP

Leo Laohoo — Tue, 24 Aug 2021 08:50:16 GMT

What model of the access point?

What firmware is the controller running on?

Re: Client cannot get IP from ex DHCP

beta_admin66 — Mon, 30 Aug 2021 08:43:26 GMT

Hello,

The reboot of the access point was unsuccessful.

Does anyone have an idea?

Model of the access point: AIR-AP1852I-E-K9

Re: Client cannot get IP from ex DHCP

Arshad Safrulla — Mon, 30 Aug 2021 10:45:33 GMT

Which model WLC you have?

Also whats the code running in WLC?

AP's are in Flex or Local (as per the logs it looks like something centrally switched)? And whats the DHCP mode configured in the WLC? (Bridge or Proxy) Please keep in mind that if the proxy mode is configured, dhcp request will be sourced from the WLC virtual IP, for this to work correctly you must configure the DHCP server IP dynamic interface. If you are using bridge mode then you configure the IP helper under the upstream switch/router/Firewall interface.