AIR-CAP3502I cannot learn option 43 from MS server

[denz_cruel]

Hi All,

Can you please help me ragarding AP AIR-CAP3502I cannot learn option 43 from MS server but it can learn the DHCP ip address. We have 2 sites that option 43 does not learned by new AP's but other site works ok.  I tried also to delete and add the dhcp scope and same issue. My temporary solution will be  creating the DHCP pool with option 43 and 60 in the access switch and it work ok, new AP's able to show in the WLC. I just need more information why site AP's cannot learn the option 43 of the MS server but other site AP's work ok. Is this IOS bug? AP's issue? MS issue?

[Scott Fella · Accepted solution]

Well the best way to check is to console into the AP and reboot it. You will see the ap obtain an IP address and either it will show that the WLC IP was found from dhcp or not. This will prove out your option 43 configuration. This will also show if something might be blocking UDP 5246 and or UDP 5247.

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[denz_cruel]

Thank you scott, We are using MS DHCP server and unknown reason new AP's can learn IP address but unable to communicate to the WLC. We also tried SPAN capture and see few details below.

switch#sh cdp nei | i AP

APacf2.c506.825c Gig 4/0/23        155               T    AIR-CAP35 Gig 0 switch#sh cdp nei | i AP
APacf2.c506.825c Gig 4/0/23        155               T    AIR-CAP35 Gig 0

SPAN capture

98 69.493943000 ac:f2:c5:06:82:5c Broadcast ARP 60 Gratuitous ARP for 10.3.59.5 (Reply)

101 81.564210000 ac:f2:c5:06:82:5c CDP/VTP/DTP/PAgP/UDLD CDP 399 Device ID: APacf2.c506.825c  Port ID: GigabitEthernet0 

106 91.500446000 ac:f2:c5:06:82:5c Broadcast ARP 60 Who has 10.3.59.1?  Tell 10.3.59.5

107 91.501761000 Cisco_8b:45:c7 ac:f2:c5:06:82:5c ARP 60 10.3.59.1 is at ac:a0:16:8b:45:c7

108 92.494773000 10.3.59.5 10.90.58.26 DNS 105 Standard query A CISCO-CAPWAP-CONTROLLER.global.com

109 92.515052000 10.90.58.26 10.3.59.5 DNS 175 Standard query response, No such name

110 92.515276000 10.3.59.5 10.90.58.26 DNS 127 Standard query A CISCO-CAPWAP-CONTROLLER.global.com

111 92.535792000 10.90.58.26 10.3.59.5 DNS 197 Standard query response, No such name

What we did we add the DHCP pool on the switch and everything work ok and we managed to remotely configure the AP's on the WLC. We removed the DHCP pool in siwtch and let the MS DHCP server do the job. We did not open a ticket to MS becaasue we know it will take time.

[Leo Laohoo]

Ok, this sounds familiar.  Can you post the following command outputs:

1.  WLC:  sh sysinfo;

2.  AP:  sh version;

3.  AP:  sh inventory;

4.  Console into the AP and reboot.  Post the entire bootup process.

[denz_cruel]

Hi Leo,

See details below, I cannot reboot the AP's because it is all working and in production after using the DHCP pool in access switch. Please note that other sites also using the same WLC and DHCP server in the datacenter and AP's work ok. This site for unknown reason it failed to communicate to WLC using the MS DHCP server.

(Cisco Controller) >show sysinfo

Manufacturer's Name.............................. Cisco Systems Inc.
Product Name..................................... Cisco Controller
Product Version.................................. 7.0.116.0
Bootloader Version............................... 1.0.1
Field Recovery Image Version..................... 6.0.182.0
Firmware Version................................. FPGA 1.3, Env 1.6, USB console                                              1.27
Build Type....................................... DATA + WPS

System Name...................................... DC-CORE-WLC

System Location..................................
System Contact...................................
System ObjectID.................................. 1.3.6.1.4.1.9.1.1069
IP Address....................................... 10.190.241.21
Last Reset....................................... Power on reset
System Up Time................................... 10 days 16 hrs 15 mins 5 secs
System Timezone Location.........................
Current Boot License Level....................... base
Current Boot License Type........................ Permanent
Next Boot License Level.......................... base
Next Boot License Type........................... Permanent

Configured Country............................... Multiple Countries:CN,GB,HK,ID                                             ,JP,SG,TH,VN

Operating Environment............................ Commercial (0 to 40 C)
Internal Temp Alarm Limits....................... 0 to 65 C
Internal Temperature............................. +44 C
External Temperature............................. +27 C
Fan Status....................................... OK

State of 802.11b Network......................... Enabled
State of 802.11a Network......................... Enabled
Number of WLANs.................................. 4
Number of Active Clients......................... 14

Burned-in MAC Address............................ 64:00:F1:F1:9B:20
Power Supply 1................................... Present, OK
Power Supply 2................................... Present, OK
Maximum number of APs supported.................. 25

AP-1>sh ver
Cisco IOS Software, C3500 Software (AP3G1-K9W8-M), Version 12.4(23c)JA2, RELEASE                                              SOFTWARE (fc3)
Technical Support: http://www.cisco.com/techsupport
Copyright (c) 1986-2011 by Cisco Systems, Inc.
Compiled Wed 13-Apr-11 12:20 by prod_rel_team

ROM: Bootstrap program is C3500 boot loader
BOOTLDR: C3500 Boot Loader (AP3G1-BOOT-M) Version 12.4(23c)JA5, RELEASE SOFTWARE                                              (fc1)

AP-1 uptime is 2 hours, 43 minutes
System returned to ROM by reload
System image file is "flash:/ap3g1-k9w8-mx.124-23c.JA2/ap3g1-k9w8-mx.124-23c.JA2                                             "
Last reload reason:

This product contains cryptographic features and is subject to United
States and local country laws governing import, export, transfer and
use. Delivery of Cisco cryptographic products does not imply
third-party authority to import, export, distribute or use encryption.
Importers, exporters, distributors and users are responsible for
compliance with U.S. and local country laws. By using this product you
agree to comply with applicable laws and regulations. If you are unable
to comply with U.S. and local laws, return this product immediately.

A summary of U.S. laws governing Cisco cryptographic products may be found at:
http://www.cisco.com/wwl/export/crypto/tool/stqrg.html

If you require further assistance please contact us by sending email to
export@cisco.com.

cisco AIR-CAP3502E-C-K9    (PowerPC460exr) processor (revision A0) with 81910K/4                                             9152K bytes of memory.
Processor board ID FGL1646S1UB
PowerPC460exr CPU at 666Mhz, revision number 0x18A8
Last reset from reload
LWAPP image version 7.0.116.0
1 Gigabit Ethernet interface
2 802.11 Radio(s)

32K bytes of flash-simulated non-volatile configuration memory.
Base ethernet MAC Address: E4:D3:F1:71:61:99
Part Number                          : 73-12175-06
PCA Assembly Number                  : 800-32268-06
PCA Revision Number                  : A0
PCB Serial Number                    : FOC16422798
Top Assembly Part Number             : 800-32904-02
Top Assembly Serial Number           : FGL1646S1UB
Top Revision Number                  : A0
Product/Model Number                 : AIR-CAP3502E-C-K9

Configuration register is 0xF

AP-1>show inv
NAME: "AP3500", DESCR: "Cisco Aironet 3500 Series (IEEE 802.11n) Access Point"
PID: AIR-CAP3502E-C-K9 , VID: V02, SN: FGL1646S1UB

AP-1>

[Scott Fella]

So besides what Leo posted, if you do a show power inline on the switch, do you see the AP name or IEEE? You should see the AP name, if you see IEEE, then it's your cabling.

That's why I mentioned to test by putting the ap on the same subnet or even console into the ap and issue a capwap ap controller IP address . If the AP doesn't join, then it's probably a layer 1 issue.

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[denz_cruel]

Hi Scott,

UAC-1#show power inline | in AIR

Gi1/0/24  auto   on         15.4    AIR-CAP3502E-C-K9   3     15.4

Gi2/0/24  auto   on         15.4    AIR-CAP3502E-C-K9   3     15.4

Gi3/0/24  auto   on         15.4    AIR-CAP3502E-C-K9   3     15.4

Gi4/0/23  auto   on         15.4    AIR-CAP3502E-C-K9   3     15.4

Gi4/0/24  auto   on         15.4    AIR-CAP3502E-C-K9   3     15.4

We dont see any layer 1 issue because the AP's can learn the IP address from the MS DHCP server. The WLC cannot see the AP's and initially we cannot remote config the AP's. Workaround was on the UAC switch we configure the DHCP Pool with option 43 and option 60 and it works OK.

Strange was that other office using same WLC and MS DHCP server the AP's works ok (WLC can see AP's initially) except this office.