WIFI

[smarshalek]

I have a Cisco 871 and have been using it to connect my laptop via wireless for about a year.

Now my laptop comes back with "Cannot connect to DHCP server" (my ISP serves up DHCP).

I have updated the laptop wifi driver, Windows is current, etc The wifi card passes all diagnostics.

I can see the laptop connecting to the router.

I have rebooted the router, cable modem, etc.

Is there something on the router that needs to be reconfigured or any other thoughts?

[garapoglou]

Hi,

Has something that has to do with the configuration of the router changed by either you or the ISP?

Could you post the router's running configuration?

Best regards,

Giorgos

[smarshalek]

Hi,

For some reason I am having trouble piping the running config (it keeps coming up currupt on the Windows side!!)

However, I have not touched the config in well over 6 months, so that has not changed. Do I need to look for something specfic?

I also wanted to add that I am pulling good IP via DHCP on all my wired ethernet connections - even laptop. I am only having trouble with the DHCP/Wifi. It worked perfectly until 3 days ago!!!

Thanks!

[paul driver]

Hi Sran,

I would say the wlan router isn’t the cause, It will be to do with your changes on the laptop. As I assume the driver you installed is appropriate for the WLAN nic?

Can you delete the WLAN profile from you laptop, and re apply it making sure you apply the correct authentication and ssid details etc..

res

Paul

[smarshalek]

Hi Paul,

I would agree, but I didn't make any changes to the previously working laptop/WLAN nic config when it stopped working. It had been working for years and then just stopped. Thats only when I updated the nic driver - yes, I updated using the exact same nic model from Dells support site. I checked the SSID, etc and it is all correct. I can see the laptop connecting to the router - it just is not pulling a valid IP via DHCP. I suppose deleting the profile might make sense, I am just wondering if the router needs a certain config for wifi...Any other thoughts?

Thanks.

[Manesh Rajan]

Hi Stran,

First confirm modem is okay and working fine, then check the router and reconfigure the router. I believe that would clear the issue..

Thanks

[smarshalek]

Hi Manesh,

Well, there is no modem involved, but as I stated, I ran internal diags againt the WLAN NIC and it is working fine. In my last post I stated the laptop is connecting to the router via wifi - I just cannot pull a valid IP. As I previously asked, what config is required on the router for WIFI/DHCP? I can pull valid IP using wired ethernet.

[smarshalek]

Ok, I deleted the Network Connection and the WLAN profile on the laptop and recreated. Still getting "No or limited connectivity", yet the signal strength is Very Good. Looks like maybe Router. Can someone assist me with what to look for in my running config, please?

[garapoglou]

Hi Stan,

Could you post the running configuration to have a look?

Regards,

Giorgos

[smarshalek]

Here you go - thanks! The gremlins must be in there changing things - I have not!!

Current configuration : 3924 bytes
!
version 12.4
no service pad
service timestamps debug datetime msec
service timestamps log datetime localtime show-timezone
no service password-encryption
!
hostname SJMRouter
!
boot-start-marker
boot-end-marker
!
logging buffered 16384 informational
enable secret 5 $1$L595$KHbJKC0kS3Nb0h2u92ojf.
!
no aaa new-model
clock timezone EST -5
clock save interval 8
!
crypto pki trustpoint TP-self-signed-3636220250
enrollment selfsigned
subject-name cn=IOS-Self-Signed-Certificate-3636220250
revocation-check none
rsakeypair TP-self-signed-3636220250
!
!
crypto pki certificate chain TP-self-signed-3636220250
certificate self-signed 01
  3082024D 308201B6 A0030201 02020101 300D0609 2A864886 F70D0101 04050030
  31312F30 2D060355 04031326 494F532D 53656C66 2D536967 6E65642D 43657274
  69666963 6174652D 33363336 32323032 3530301E 170D3032 30373139 30313133
  32385A17 0D323030 31303130 30303030 305A3031 312F302D 06035504 03132649
  4F532D53 656C662D 5369676E 65642D43 65727469 66696361 74652D33 36333632
  32303235 3030819F 300D0609 2A864886 F70D0101 01050003 818D0030 81890281
  8100CF48 90F82435 DBE17A1F F5029D03 ED3B34CB 4ED603E2 6DAACB5E 12517DFD
  7CF44AC3 F69DD671 CF72F4D6 C736C7E3 E7D5297C 6F87EBD4 4F7255DF 09B30998
  7C40916A 325338F2 FF43717B 6D6B7598 186931A2 A6E97688 FC691B1C F9420E15
  92579F6E 89AB7D96 9A4F2380 310A3CD0 59C4C5DC E044ABE6 646E2992 0BDB18AC
  069B0203 010001A3 75307330 0F060355 1D130101 FF040530 030101FF 30200603
  551D1104 19301782 15534A4D 526F7574 65722E63 6F6D6361 73742E6E 6574301F
  0603551D 23041830 1680144F 249744C1 828F85DD F4ABD9F3 698EE514 9B0B3F30
  1D060355 1D0E0416 04144F24 9744C182 8F85DDF4 ABD9F369 8EE5149B 0B3F300D
  06092A86 4886F70D 01010405 00038181 00864127 E9D5E8C9 5C3AB322 33A336DB
  1C0CACDC E5138E1B AA194C60 0AA661C5 C9594EFA 686B96B9 EB1F4A19 B07D0F54
        quit
dot11 syslog
ip cef
no ip dhcp use vrf connected
ip dhcp excluded-address 192.168.1.1 192.168.1.99
!
ip dhcp pool LANDHCP
   import all
   network 192.168.1.0 255.255.255.0
   default-router 192.168.1.1
   dns-server 68.87.77.134 68.87.72.134
   lease 3
!
!
ip domain name comcast.net
!
!
!
!
archive
log config
  hidekeys
!
!
ip ssh version 2
!
!
!
interface Loopback0
no ip address
!
interface FastEthernet0
!
interface FastEthernet1
!
interface FastEthernet2
!
interface FastEthernet3
!
interface FastEthernet4
description INTERNET WAN PORT
ip address dhcp
ip nat outside
ip virtual-reassembly
duplex auto
speed auto
!
interface Dot11Radio0
description WLAN Port
no ip address
shutdown
speed basic-1.0 basic-2.0 basic-5.5 6.0 9.0 basic-11.0 12.0 18.0 24.0 36.0 48.0
54.0
station-role root
!
interface Vlan1
description $ETH-SW-LAUNCH$$INTF-INFO-HWIC 4ESW$
ip address 192.168.1.1 255.255.255.0
ip nat inside
ip virtual-reassembly
ip tcp adjust-mss 1452
!
ip default-gateway 76.112.248.1
ip forward-protocol nd
!
ip http server
ip http authentication local
ip http secure-server
ip http timeout-policy idle 60 life 86400 requests 10000
ip nat inside source list 1 interface FastEthernet4 overload
!
logging source-interface Loopback0
access-list 1 permit 192.168.1.0 0.0.0.255
no cdp run
!
!
!
control-plane
!
banner motd
=====================================================
This is a secure router, unauthorized logins
are restricted.
=====================================================

!
line con 0
exec-timeout 30 0
logging synchronous
login
no modem enable
line aux 0
line vty 0 4
access-class 23 in
exec-timeout 20 0
privilege level 15
logging synchronous
login local
transport input telnet ssh
!
scheduler max-task-time 5000
end

[sudharsan_n]

Hi Stan,

Regarding the Wireless side configuration,

     ======part of the config from your router ============

     !

     interface Dot11Radio0

     description WLAN Port

     no ip address

     shutdown

     speed basic-1.0 basic-2.0 basic-5.5 6.0 9.0 basic-11.0 12.0 18.0 24.0 36.0 48.0

     54.0

     station-role root

     !

     ====================

The interface dot11radio0 is your wireless interface. However the interface command is "SHUTDOWN". Meaning the wireless signal strength might be full or partial, since the interface is SHUTDOWN you may not access your LAN or WAN.

If you have not changed the config for months it may be from ISP side who have made the changes and might have by accident forgot to " no shutdown" that interface. You can contact them and with thier concurrence you can try enabling the interface "Dot11Radio0"

Hope that should help.

Cheers,

Sudharsan

[smarshalek]

Hi Sudharsan,

I noticed the same thing and thought that was strange. It seems logical that could be at least part of the problem.

I am sorry to ask you this, but what method do you use to edit the running config? It has been so long since I did that.

Can you help, please?

Thanks!

[sudharsan_n]

Since you have taken the running config, I assume you have the appropriate rights to edit that.

However to enable the interface, once you are in the privileged mode (i.e # prompt), you can try the follwing.

=======Enabling the Wireless interface ===================

SJMRouter#conf t

SJMRouter(config)#int Dot11Radio0

SJMRouter(config-if)#no shut

============ End ==============

========== Saving the config file from running to startup ==================

After doing the above changes, the following needs to be done to save in the startup config.

This will make the changes in the startup config as well, that means if ever rebooted the router, that running config will be erased and will be replaced with the old config file. To avoid that the following needs to be done.

          SJMRouter#copy run start

and hit enter. It will say

          Destination filename [startup-config]?

again hit enter. It will say

           [OK]

======End ====================

Hope that helps you.

Cheers,

Sudharsan.

[smarshalek]

Yes!! It came back to me once you sent that (I need to review the IOS command guide again!)

The only difference was I had to change the console mode to do the copy...

Thank you so much!

I need to go test now.

[smarshalek]

Hi Sudharsan and all,

Well, I am at a loss. Did not work. I was sure the shutdown on dot11radio0 was the problem.

I applied the correct changes, updated the startup, rebooted the router, but I get same error.

Limited or no connection. Yet the signal is good. My laptop is still pulling a 169.x.x.x IP.

Any other thoughts out there?

Thanks. again.