networking - Linux clients and Windows Servers can connect but not windows clients

This is driving me insane because I can't make head or
tails of it.

We have two DCs (W2K3 SP1) and I'v
tried this once on each machine as a sanity
check.

DHCP is being served by either one of the
machines and all machines get an address no problem. The servers can connect/ping/browse
to the www and so can all our linux clients. But NONE of our windows clients (all
windows 7).

I can do anything within the
network, I can even ping the firewall/router but nothing from the windows clients is
leaving the confines of our subnet.

I don't get
it. The linux and windows clients are both served from the same DHCP server, the gateway
is the same, everything is the
same.

Anyone care to take a shot at
how to resolve this?

I tried adding explicit
routes at the clients, but still no go.

Some
points that might help:

This is behind a
SonicWall firewall (which I absolutely despise).
The DCs are two VMs on two
different boxes.
DHCP being provided by these VMs. There is maybe 1/2 dozen
other VMs that act as web or database servers and they can all connect to the
internet.
The issue happened this morning (my time is GMT +2) and I think its
a result of issues on the VMs. The domain was built in what I can only kindly refer to
as a patchy manner. Dealing with it is like running my cojones in a
shredder.

Connection has proven to be
an intermittent thing. On several of the Windows 7 clients, connection was restored for
no obvious reason for a few minutes before it went
away.

Nothing has been changed when it comes to
domain policies for at least a few weeks now.

I
can't think of anything else to add, but if there's something in specific, y'all just
ask and I'll be more than happy to provide an
answer.

TIA

SMIM

@John
Gardeniers

I'm at home now so I'll post it
tomorrow when I get to the office, but I did that when I was there and the gateway and
DNS servers are right. DNS resolution is
correct.

This is the ipconfig /all output on one
of the clients that started to work magically after I turned
off the
DHCP

Windows IP
            Configuration

 Host Name . . . . . . . . . . . . :
            TAN-LEN-08

 Primary Dns Suffix . . . . . . . :
 Node Type
            . . . . . . . . . . . . : Hybrid
 IP Routing Enabled. . . . . . . . :
            No
 WINS Proxy Enabled. . . . . . . . : No
 DNS Suffix Search List.
            . . . . . :
            tanasuk.lcl

********************************************************************
Wireless
            LAN adapter Wireless Network Connection:

 Connection-specific DNS
            Suffix . : tanasuk.lcl

 Description . . . . . . . . . . . :
            Intel(R) WiFi Link 5100 AGN
 Physical Address. . . . . . . . . :
            00-21-5D-77-8F-D2
 DHCP Enabled. . . . . . . . . . . : Yes

            Autoconfiguration Enabled . . . . : Yes
 Link-local IPv6 Address . . . . . :
            fe80::c864:eeb4:cb19:40cf%12(Preferred)
 IPv4 Address. . . . . . . . . . . :
            192.168.186.151(Preferred)
 Subnet Mask . . . . . . . . . . . :
            255.255.255.0
 Lease Obtained. . . . . . . . . . : Monday, January 17, 2011
            9:48:50 AM
 Lease Expires . . . . . . . . . . : Monday, January 17, 2011
            2:48:51 PM
 Default Gateway . . . . . . . . . :
            192.168.186.1

 192.168.186.5
 DHCP Server . . . . . . . .
            . . . : 192.168.186.6
 DHCPv6 IAID . . . . . . . . . . . :
            218112349
 DHCPv6 Client DUID. . . . . . . . :
            00-01-00-01-14-4F-8A-A2-00-22-15-EB-3B-2F

 DNS Servers . . . . . .
            . . . . . : 192.168.186.5
 192.168.186.6
 Primary WINS Server . . .
            . . . . : 192.168.186.6
 NetBIOS over Tcpip. . . . . . . . :
            Enabled
********************************************************************


Ethernet
            adapter Local Area Connection:

 Media State . . . . . . . . . . . :
            Media disconnected
 Connection-specific DNS Suffix . :
 Description
            . . . . . . . . . . . : Realtek RTL8168C(P)/8111C(P) Family PCI-E
 Gigabit
            Ethernet NIC (NDIS 6.20)
 Physical Address. . . . . . . . . :
            00-22-15-EB-3B-2F
 DHCP Enabled. . . . . . . . . . . : Yes

            Autoconfiguration Enabled . . . . : Yes


Tunnel adapter
            Teredo Tunneling Pseudo-Interface:

 Media State . . . . . . . . . .
            . : Media disconnected
 Connection-specific DNS Suffix . :

            Description . . . . . . . . . . . : Teredo Tunneling Pseudo-Interface

            Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0
 DHCP Enabled. . .
            . . . . . . . . : No
 Autoconfiguration Enabled . . . . :
            Yes


Tunnel adapter
            isatap.tanasuk.lcl:

 Media State . . . . . . . . . . . : Media
            disconnected
 Connection-specific DNS Suffix . : tanasuk.lcl

            Description . . . . . . . . . . . : Microsoft ISATAP Adapter #2
 Physical
            Address. . . . . . . . . : 00-00-00-00-00-00-00-E0
 DHCP Enabled. . . . . . .
            . . . . : No
 Autoconfiguration Enabled . . . . :
            Yes

Obviously,
the one I tagged with asterisks is the one we're looking at.

Its right, the gateway should be and is
192.168.186.1, the DNS servers are 192.168.186.5|6 everything is right.

The weird thing is that things started to work
after DHCP server was turned off! In my exasperated attempts, I
even tried a linux server (CentOS 5.3 dhcpd) with the exact same
results.

Any idea guys? I'm stumped and I'd LOVE
to know what the heck is going on.

Here is the
ipconfig /all output off of one of the DCs/DNS
servers

Windows IP
            Configuration

 Host Name . . . . . . . . . . . . :
            TAN-SRV-DC2
 Primary Dns Suffix . . . . . . . : tanasuk.lcl
 Node
            Type . . . . . . . . . . . . : Hybrid
 IP Routing Enabled. . . . . . . . :
            No
 WINS Proxy Enabled. . . . . . . . : No
 DNS Suffix Search List.
            . . . . . : tanasuk.lcl

Ethernet adapter Local Area Connection
            2:


 Connection-specific DNS Suffix . :

            Description . . . . . . . . . . . : Citrix XenServer PV Ethernet Adapter

            Physical Address. . . . . . . . . : A2-A9-A1-B4-FA-08
 DHCP Enabled. . . . . .
            . . . . . : No
 IP Address. . . . . . . . . . . . : 192.168.186.6

            Subnet Mask . . . . . . . . . . . : 255.255.255.0
 Default Gateway . . . . . .
            . . . : 192.168.186.1
 DNS Servers . . . . . . . . . . . :
            192.168.186.5

            192.168.186.6

and
this is off of my local linux laptop (ifconfig
eth0)

eth0 Link encap:Ethernet
            HWaddr 00:16:6f:55:07:e3 
 BROADCAST MULTICAST MTU:1500 Metric:1
 RX
            packets:304 errors:0 dropped:0 overruns:0 frame:0
 TX packets:61 errors:0
            dropped:5 overruns:0 carrier:0
 collisions:0 txqueuelen:1000 
 RX
            bytes:47811 (47.8 KB) TX bytes:12238 (12.2 KB)

 Interrupt:22
            Memory:bc007000-bc007fff

(less
/etc/resolv.conf)

# Generated by
            NetworkManager
nameserver 192.168.186.5
nameserver
            192.168.186.6

and
(route -n output)

Kernel IP
            routing table
Destination Gateway Genmask Flags Metric Ref Use
            Iface
192.168.186.0 0.0.0.0 255.255.255.0 U 1 0 0 eth1
192.168.122.0
            0.0.0.0 255.255.255.0 U 0 0 0 virbr0
169.254.0.0 0.0.0.0 255.255.0.0 U 1000 0
            0 eth1
0.0.0.0 192.168.186.1 0.0.0.0 UG 0 0 0
            eth1

As you
can see, this is insane!

There is something I
have noticed since the problem has now become intermittent. Some Windows 7 laptops will
connect, others will not and some will connect for a bit and then just
forget.

They connect perfectly fine locally. And
though they have a gateway defined, its almost as if they don't know how to reach it.
Trying a tracert, I get a timeout from the first hop, but not so on the *nix clients
(CentOS, several Ubuntu, several Mac OS X). Could this be a DNS issue? as in both DCs
aren't synching properly?