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Laptop restricted to LAN, can't use WAN resources

The WAN is divided into 4 LANs at 4 locations. We have a laptop which usually connects by wireless to the 10.2.1.x LAN and can use all network resources there without problems. (It's only just occurred to me that the user never attempted to connect to resources at branch locations from the head office.) Now the laptop is connected to the 10.2.4.x LAN and can only use network resources on the local network. Pinging addresses in other locations gets "Reply from 10.2.4.1: Destination host unreachable" messages.

The laptop is configured to obtain IP addresses automatically and now has a 10.2.4.x address as expected. Subnet mask is unchanged (255.255.255.0, same all over the WAN) and default gateway is 10.2.4.1. The DNS server address (also obtained automatically) is the local 10.2.4.x server as expected.

The gateway 10.2.4.1 is a Cisco 1700 router, but I'm a novice at these and don't know how to check whether that is misconfigured. I have tried resetting the router, but with no effect.

Other laptops can move from location to location around the WAN without problems. What's going wrong here?

Thanks in advance
anseris
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myin68
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Are you saying you can take any other laptop, plug it into any LAN segment and it can ping all other LANs?  If this is not the case, then you probably need to modify your router configurations.

What kind of WAN connectivity are you using?  Point-to-Point leased lines, Frame relay, dsl, or other?
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anseris

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Other laptops can connect to any LAN segment and ping all other LANs, correct.

The branch LANs are connected by leased lines to the head office LAN (10.2.1.x).
Go to a command prompt and issue the command:
ROUTE PRINT
and post the results.  Maybe there is a static route setup that is messing things up.
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ASKER

===========================================================================
Interface List
0x1 ........................... MS TCP Loopback interface
0x2 ...00 16 d3 25 74 6d ...... Broadcom NetXtreme Gigabit Ethernet - Packet Sch
eduler Miniport
0x10004 ...00 16 ce ed 90 65 ...... Bluetooth Device (Personal Area Network)
===========================================================================
===========================================================================
Active Routes:
Network Destination        Netmask          Gateway       Interface  Metric
          0.0.0.0          0.0.0.0         10.2.4.1      10.2.4.106       20
         10.2.4.0    255.255.255.0       10.2.4.106      10.2.4.106       20
       10.2.4.106  255.255.255.255        127.0.0.1       127.0.0.1       20
   10.255.255.255  255.255.255.255       10.2.4.106      10.2.4.106       20
        127.0.0.0        255.0.0.0        127.0.0.1       127.0.0.1       1
        224.0.0.0        240.0.0.0       10.2.4.106      10.2.4.106       20
  255.255.255.255  255.255.255.255       10.2.4.106      10.2.4.106       1
  255.255.255.255  255.255.255.255       10.2.4.106           10004       1
Default Gateway:          10.2.4.1
===========================================================================
Persistent Routes:
  None
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ASKER

I just ran route print on this machine, and the response was identical (other than the different IP address) except that it doesn't have the last line of active routes - the one with the interface 10004.
Hi,

Have you tried repairing your network connection (right-click the network icon while it's connected and click repair)? This would clear all data about the DNS cache, netbt, etc.

Hope this helps.
The routing table looks ok.  Do a:
TRACERT 10.2.1.something on that network and post.

What are you using for your router?  Is it a firewall?  Do you have a rule setup that only allows certain IP's or MAC's to pass through to your other networks?
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Tried repairing the network connection. No joy.

The router at 10.2.4.1 is a Cisco 1700, not a firewall. As I said I'm a novice at these, so if that answer betrays any naivete please explain more. I'm not aware of any MAC filtering - as we've been able to connect any number of other computers without any trouble I'm pretty sure there isn't any. The laptop IP address comes from the local server DHCP range so won't be blocked.

TRACERT output:

>tracert 10.2.1.2

Tracing route to 10.2.1.2 over a maximum of 30 hops

  1    <1 ms    <1 ms    <1 ms  10.2.4.1
  2  10.2.4.1  reports: Destination net unreachable.

Trace complete.
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robrandon

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Problem solved, though I'm not sure why. I set a static IP as robrandon suggested, first trying the laptop's usual 10.2.1.x address and then trying a 10.2.4.x address. Neither resolved the issue, but when I changed the laptop back to DHCP, suddenly it could see the entire WAN!

Anyone care to speculate as to why? The user was lucky that someone with some IT knowledge was in the same location when the problem happened, but I'm worried that it will happen again when she travels to another location and I'm not there, and her laptop won't be visible over the network.

I ran the route print command again after the problem was resolved, and the output is below. The address is different, but also the final line in the previous output is gone - the line with the interface 10004 instead of an IP address. Is this a normal interface?

>route print
===========================================================================
Interface List
0x1 ........................... MS TCP Loopback interface
0x2 ...00 16 d3 25 74 6d ...... Broadcom NetXtreme Gigabit Ethernet - Packet Sch
eduler Miniport
===========================================================================
===========================================================================
Active Routes:
Network Destination        Netmask          Gateway       Interface  Metric
          0.0.0.0          0.0.0.0         10.2.4.1      10.2.4.178       20
         10.2.4.0    255.255.255.0       10.2.4.178      10.2.4.178       20
       10.2.4.178  255.255.255.255        127.0.0.1       127.0.0.1       20
   10.255.255.255  255.255.255.255       10.2.4.178      10.2.4.178       20
        127.0.0.0        255.0.0.0        127.0.0.1       127.0.0.1       1
        224.0.0.0        240.0.0.0       10.2.4.178      10.2.4.178       20
  255.255.255.255  255.255.255.255       10.2.4.178      10.2.4.178       1
Default Gateway:          10.2.4.1
===========================================================================
Persistent Routes:
  None
It looks like somehow before you had 2 default gateways
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Sorry, myin68, I don't follow. I only see one default gateway on the first set of output?
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Sorry this is taking so long, I've been travelling the past 2 days and was without internet access.

I found another laptop with the same problem. Setting a static address as robrandon suggested resolved the issue. So robrandon gets the points, though I'm still not sure what's going on here.

Thanks to all who responded!
It's probably a rule or access list on your firewall/router.  Glad you found a work-around at least.
Disabling your bluetooth will also remove this interface. In my case the interface was my wireless card. It is listed in the interfaces section of route print. Not sure this is going to resolve the issue though.