Re: Internet Intermittent Connection

First of all, Here are my IPs for the network:

Internal Network: 192.168.100.1 - 192.168.100.255
ISA Internal NIC: 192.168.100.1
ISA External NIC: 192.168.1.100
Modem Internal: 192.168.1.254
Modem External: Public IP Address

Please read my comments below and thanks a lot for the help, I feel we are
getting closer.

"Mohammed A. Raslan" wrote:

Ok it looks like there is something wrong with your ISA server
configuration. First of all double check the "Internal" Network and make
sure it only contains your internal IP range (The entire internal range
which must include the IP of the ISA NIC connected to the internal LAN),
don't add the private address (10.x.x.x, 172.16.x.x - 172.31.x.x,
192.168.x.x) for the moment, just your internal lan addresses only. one
thing that can help is to open the "Internal" network properties and on the
"Addresses" tab, instead of adding address, use the add adapter option,
which should only select your internal network range, you then should add
any other networks and remove any additional ranges if they are added.

The range on the Internal Network defined in ISA is 192.168.100.1 -
192.168.100.255, I did not do any changes to this setting as it seems fine.
I should also mention that the external NIC is actually the built-in NIC
where is the Netgear NIC I added is used as the internal NIC. Would this be a
problem?


Second, double check the ISA server routing table, make sure that all routes
to the internal networks are going trough the internal NIC, and all "other"
networks which should be external to ISA are going through the external ISA
NIC. use the "route print" command to check this.

Boy, this is one area I don't have much experience in. The routing table is
as follows:
===========================================================================
Active Routes:
Network Destination Netmask Gateway Interface Metric
0.0.0.0 0.0.0.0 192.168.1.100 192.168.100.1 1
0.0.0.0 0.0.0.0 192.168.1.254 192.168.1.100 1
127.0.0.0 255.0.0.0 127.0.0.1 127.0.0.1 1
192.168.1.0 255.255.255.0 192.168.1.100 192.168.1.100 1
192.168.1.100 255.255.255.255 127.0.0.1 127.0.0.1 1
192.168.1.255 255.255.255.255 192.168.1.100 192.168.1.100 1
192.168.100.0 255.255.255.0 192.168.100.1 192.168.100.1 1
192.168.100.1 255.255.255.255 127.0.0.1 127.0.0.1 1
192.168.100.255 255.255.255.255 192.168.100.1 192.168.100.1 1
224.0.0.0 224.0.0.0 192.168.1.100 192.168.1.100 1
224.0.0.0 224.0.0.0 192.168.100.1 192.168.100.1 1
255.255.255.255 255.255.255.255 192.168.1.100 192.168.1.100 1
Default Gateway: 192.168.1.254
===========================================================================

Does that look right? If not, how can I adjust it?


Third, do you have any VPN site to site networks? if you have any other
defind networks other that the default networks, try for the moment to
delete them. only keep the defualt networks, or double check that they are
correct. and going through the correct interfaces.

I don't have any VPNs, so we don't have to worry about that.


Finally, make sure that if your DSL modem is NATting to the internet that
the network between the Modem internal interface and the ISA external
interface is not included in the "Internal" network in ISA

As you can see, the Internal network is defined as: 192.168.100.1 -
192.168.100.255
The ISA external NIC is directly connected to the modem Internal NIC.


Regarding connecting a single client and checking the ISA configuration, you
said nothing changed, just want to make sure that you mean the problem still
exists.

That's correct, the problem still exists.



waiting for you reply.
Regards,
Mohammed A. Raslan


"Access Lover" <AccessLover@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote in message
news:8C7A812F-E045-4C0B-A7FC-1EA35674A43C@xxxxxxxxxxxxxxxx
Thank you for the reply and sorry about the missing info.

I am running ISA 2004 Basic SP2 on Win2K Server SP4 and all clients are
WinXP Pro SP2. I tried to connect only one client through ISA, but nothing
changed. But I did notice these errors all over the Event Viewer
Application
Log and I am not sure if it is relevant to this problem or not:

Warning-Event ID 14141
"ISA Server detected a proxy chain loop. There is a problem with the
configuration of the ISA Server routing policy."

Error-Event ID 14147
"ISA Server detected routes through adapter NETGEAR FA311/FA312 PCI
Adapter
that do not correlate with the network element to which this adapter
belongs.
For best practice, the address range of an ISA Server network should match
the address ranges routable through the associated network adapter as
defined
in the routing table. Otherwise valid packets may be dropped as spoofed.
(This alert may occur momentarily when you create a remote site network.
You
may safely ignore this message if it does not reoccur.) The address
ranges
in conflict are:
0.0.0.1-126.255.255.255;128.0.0.0-192.168.0.255;192.168.2.0-192.168.99.255;192.168.101.0-223.255.255.255;.
"

Error-Event ID 14147
ISA Server detected routes through adapter NDIS 5.0 driver that do not
correlate with the network element to which this adapter belongs. For best
practice, the address range of an ISA Server network should match the
address
ranges routable through the associated network adapter as defined in the
routing table. Otherwise valid packets may be dropped as spoofed. (This
alert
may occur momentarily when you create a remote site network. You may
safely
ignore this message if it does not reoccur.) The address ranges in
conflict
are:
0.0.0.1-126.255.255.255;128.0.0.0-192.168.0.255;192.168.2.0-192.168.99.255;192.168.101.0-223.255.255.255;.

Thanks you



"Mohammed A. Raslan" wrote:

What version of ISA do you work with?
I guess its ISA 2000.
Anyway most probably its some on the LAN that has a spyware or infected
by a
virus that is flooding the ISA server with packets ore requests.
Try to monitor your clients, try isolating some clients and check how the
server will react. Put some restrictive rules on the clients access to
the
internet.
Make sure that your ISA Server OS and ISA Server software are a the
latest
serivce pack and host fixes.

Try to send more details such as the verison of ISA and the OS you have.

Hope this helps
Regards,
Mohammed A .Raslan

"Access Lover" <AccessLover@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote in message
news:563CF870-9993-4710-A340-8C2C3712D4B7@xxxxxxxxxxxxxxxx
Hello,

I have an intermittent Internet connection that has been going on for
the
past 6 months and you can imagine what kind of chaos it has done.

The problem is summed up as follows which could have a simple solution,
only
I don't know about it:

The Physical Connection:

We have a DSL line that is connected to a DSL modem with two ports. One
port
is for the DSL line (RJ11) and the other port is going to our ISA
server
(RJ45). The ISA server has two network cards. One card as mentioned is
connected to the DSL modem, while the other one is going to the private
network. NAT with Private IP addresses are implemented on the network.

The Problem:

Connection to the Internet is ok on the ISA server as well as the rest
of
the network...just for a while.
The ISA server (as well as the whole network) looses Internet
connection
intermittently after a couple of hours, 6 hours or one day. It varies,
but
all I have to do is reboot the ISA server and Internet connection comes
back.

Tried Solutions:

1.I have replaced the DSL modem from Bellsouth with a simple modem,
also
from Bellsouth, with only two ports and no DHCP nor NAT, but the
problem
still occurs.
2.I have changed the CAT5 wires to no avail.
3.I have tried to corner the problem by taking out the whole network
including ISA and only hooked up a PC with a static IP address of
directly
to
the modem. I did not loose Internet connection which really means that
the
modem is not the problem.

I would really appreciate any help on this problem, thanks,






.

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