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PIX 501 - ADSL modem connectivity problem


We have PIX 501 firewall outside interface connected via a cross-over cable to a Verilink IADs 8000 which is basically an ADSL modem. Everything worked fine until recently. Now there seems to be no connection between the PIX and the modem, I cannot ping default gateway of the PIX. We checked cabling, replaced the PIX and the cross-over cable with the same result. I connected a laptop directly to the modem instead of the PIX and there still was no connectivity. Then I played with the laptop NIC settings and found out that if the NIC is set to 10MBit/Half duplex the connection works. Now I setup PIX outside interface port to 10baset, there is a connection but with a lot of time-outs when pinging remote host. I replaced the PIX with cheap NetGear firewall and it was working straight away. Finally I placed a switch between the PIX and the modem and it worked.

To sum up the test results:

Production PIX - no connection

Replacement PIX - no connection

Laptop (NIC on auto) - no connection

Laptop (10mb/half) - connected

Prod PIX on 10MB/half - connected with drop-outs

NetGear firewall - connected

We have got four other locations with exactly the same config PIX 501-ADSL Verilink 8000 and all works fine.

It seems to me we are having some ethernet-level problem between the PIX and the modem. Our provider does accept they modem could be faulty as long as we managed to connect from the laptop.

Now the questions.

1. Why the PIX does not have connectivity when connected directly and it does when connected via a switch?

2. Is there any way to look into what is happening on the PIX interface at the ethernet level?

Any thoughts, advice, suggestion on troublshooting and, possibly, shifting the blame to provider are greatly appreciated.

Thank you.


Re: PIX 501 - ADSL modem connectivity problem

Try replacing the modem. Any chance you can switch it out with one that you know works from one of the other sites or something?

If it works it helps "prove" to the provider that their equipment is faulty.

Hope this helps


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