Macbook Pro wireless network connection problem

On the System Preferences->Network->Airport->Advanced on the Macbook Pro's that do not connect, check if you have several network names defined in the list and if the checkbox for Remember any network this computer has joined.

See if the preferred search order is choosing a cached entry which conflicts with your existing network. See if the Macbook Pros that work have a different list of network names and if their entries are correct.

I deleted all saved connections from 1 users mac and created a new one, but same issue. The Mac's Airport reports that they are connected to the wireless network, but they cannot load a web page.

Once the user is connected as you mentioned, open up a Terminal prompt on that machine and enter the following:

$ ifconfig en1

This will grab the information assigned to the wireless adapter (typically en1) and verify that the IP address and subnet mask assignments are correct for this WLAN (assuming the AP assigned a DHCP address to your machine)

$ netstat -rn

This will show the current routing table and verify that you have a default gateway that is pointing to the proper destination for the WLAN. If the wireless is enabled and you are also attached to a wired connection, ensure the gateways are not still pointing to your wired connection.

$ more /etc/resolv.conf

Verify that the assigned domain and nameserver entries are pointing the proper addresses for name resolution. Test this out as follows

$ dig www.yahoo.com

You should have it return the information/IP address information for the website. If not, you may not be pointing to a valid/allowed DNS source or your gateway could potentially be incorrect.

$ traceroute www.yahoo.com

If the dig command returns a valid IP, try using this command to verify your IP traffic is taking the path through the network as needed. You had mentioned that other Macs were working from the same AP so I would imagine that the same command issued on the working Mac and the one not working should deliver similar results

Assuming you may be using Safari, check under Safari->Preferences->Advanced->Proxies (click on Change Settings button) and verify on the working Mac the settings used for Proxies to determine if there is anything that might be missing on the other Macs

Lastly, verify if your network switch equipment is using a proxy redirection for port 80/443 and if so, is the working Mac listed in an exception table and the other Mac are not yet listed?

Thanks, I'll look at your suggestions.

Update: I was able to use the wireless connection to access the management console of the router and access points within our lan but no outside websites by name or IP address?

1. What are the results of the DIG, Traceroute, and other items previously mentioned

2. Verify settings for /etc/resolv.conf show domain/dns information assigned by your DHCP source

3. Verify that the subnet mask and gateway settings are correct and match the router's settings for Wifi
    You mentioned that jacked into ethernet works, but Wifi does not - double check the subnet mask definitions
    on AP/Router/Your Mac are all correct for the segment assigned to Wifi

4. Can Mac Browser access any HTTP source internal to your Lan correctly? (web interface of internal router?)

1. What are the results of the DIG, Traceroute, and other items previously mentioned: not completed, how to set up a terminal prompt on a mac, the Macs are the users personal equipment, they don't know how to do this.

2. Verify settings for /etc/resolv.conf show domain/dns information assigned by your DHCP source: not completed, how to set up a terminal prompt on the mac, the Macs are the users personal equipment, they dont know how to do this.
3. Verify that the subnet mask and gateway settings are correct and match the router's settings for Wifi
    You mentioned that jacked into ethernet works, but Wifi does not - double check the subnet mask definitions
    on AP/Router/Your Mac are all correct for the segment assigned to Wifi: All on same segment: 255.255.255.0.
4. Can Mac Browser access any HTTP source internal to your Lan correctly? (web interface of internal router?): Yes.

Provide these instructions to your users and return a snapshot of what they have:

Starting Terminal Session
1. From main Mac desktop use the Finder pulldown menu and click Go->Utilities and double click Terminal
2. Issue the following commands as shown in the sample below

Last login: Fri Dec  5 10:24:32 on ttys000
SieversMBP:~ admin$ ifconfig en0                             (NOTE: You enter ifconfig en0 and press return)

en0: flags=8863<UP,BROADCAST,SMART,RUNNING,SIMPLEX,MULTICAST> mtu 1500
    ether 00:16:cb:8b:be:49
    media: autoselect status: inactive
    supported media: autoselect 10baseT/UTP <half-duplex> 10baseT/UTP <full-duplex> 10baseT/UTP <full-duplex,hw-loopback> 10baseT/UTP <full-duplex,flow-control> 100baseTX <half-duplex> 100baseTX <full-duplex> 100baseTX <full-duplex,hw-loopback> 100baseTX <full-duplex,flow-control> 1000baseT <full-duplex> 1000baseT <full-duplex,hw-loopback> 1000baseT <full-duplex,flow-control> none
SieversMBP:~ admin$
SieversMBP:~ admin$

SieversMBP:~ admin$ ifconfig en1                            (NOTE: You enter ifconfig en1 and press return)
en1: flags=8863<UP,BROADCAST,SMART,RUNNING,SIMPLEX,MULTICAST> mtu 1500
    inet 192.168.0.14 netmask 0xffffff00 broadcast 192.168.0.255
    ether 00:1b:63:f0:40:03
    media: autoselect status: active
    supported media: autoselect
SieversMBP:~ admin$
SieversMBP:~ admin$

SieversMBP:~ admin$ cat /etc/resolv.conf                (NOTE: You enter cat /etc/resolv.conf and press return)
nameserver 68.87.64.146
nameserver 68.87.75.194
nameserver 68.87.71.226
SieversMBP:~ admin$
SieversMBP:~ admin$

SieversMBP:~ admin$ netstat -rn                                (NOTE: You enter netstat -rn and press return)
Routing tables

Internet:
Destination        Gateway            Flags    Refs      Use  Netif Expire
default            192.168.0.1        UGSc       58        3    en1
10.37.129/24       link#9             UCS         0        0    en2
10.37.129.3        127.0.0.1          UHS         0        0    lo0
10.211.55/24       link#10            UCS         0        0    en3
10.211.55.6        127.0.0.1          UHS         0        0    lo0
127                127.0.0.1          UCS         0        0    lo0
127.0.0.1          127.0.0.1          UH          1        2    lo0
169.254            link#6             UCS         0        0    en1
172.16.233/24      link#7             UC          0        0 vmnet8
192.168.0          link#6             UCS         4        0    en1
192.168.0.1        0:12:17:e9:cf:18   UHLW       15       20    en1    786
192.168.0.14       127.0.0.1          UHS         0        0    lo0
192.168.0.76       0:1f:32:63:d0:fa   UHLW        0        0    en1    791
192.168.185        link#8             UC          0        0 vmnet1

Internet6:
Destination                             Gateway                         Flags      Netif Expire
::1                                     link#1                          UHL         lo0
fe80::%lo0/64                           fe80::1%lo0                     Uc          lo0
fe80::1%lo0                             link#1                          UHL         lo0
ff01::/32                               ::1                             U           lo0
ff02::/32                               fe80::1%lo0                     UC          lo0
SieversMBP:~ admin$

3. After all data appears within the terminal use the Edit pulldown and click Select All
4. Click the Edit pulldown and click Copy
5. Open up your Mail application and use the Edit pulldown and click Paste
6. Have them email this to you and post the results obtained here so the folks online can help diagnose your issues