IDS mailing list archives
Re: Auto-sensing for IPS devices
From: Packet Man <packetman () altsec info>
Date: Fri, 16 Sep 2005 22:44:01 -0500
ferg () furg net wrote:
Hi there, In a typical enterprise IPS deployment would it be normal to leave auto-sensing on the IPS and on the switches it was connected to, especially in 10/100/1000, or would it be wiser to set both ends to a particular speed? I have heard there may be issues with CRC errors etc.
Ferg; My experience has been, even with large networks, that the switch ports should be set to the desired mode, bypassing autonegotiation. Regarding almost all auto-negotiation problems, they crop up when there's a conflict between the timing of the link peers trying to sync up and they're both set to negotiate. It's kind of like two chatty gossips trying to talk at the same time - they're always interrupting each other. This problem is pretty well documented for many pairs of common network switch/NIC combinations, where switch brand A is known to fail negotiation with NIC brand B. Setting a switch port to 100-TX will force any decent NIC on a host to link up at that setting. I would trash any NIC that doesn't. It's not necessary to force the link mode of the NIC if the switch doesn't auto-negotiate - the host NIC will find the desired link setting. You can force the setting for both the switch port and host NIC, but that can create a management nightmare for sure. I hope this helps. It's just the way I do things. Your mileage may vary. :) Mark - - - - - - - - - - - - - - http://www.altsec.info ------------------------------------------------------------------------ Test Your IDS Is your IDS deployed correctly?Find out quickly and easily by testing it with real-world attacks from CORE IMPACT. Go to http://www.securityfocus.com/sponsor/CoreSecurity_focus-ids_040708 to learn more.
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Current thread:
- Auto-sensing for IPS devices ferg (Sep 14)
- Re: Auto-sensing for IPS devices Lachlan Bowes (Sep 14)
- Re: Auto-sensing for IPS devices Joel M Snyder (Sep 15)
- Re: Auto-sensing for IPS devices Lachlan Bowes (Sep 15)
- Re: Auto-sensing for IPS devices Joel M Snyder (Sep 15)
- Re: Auto-sensing for IPS devices Tim Holman (Sep 15)
- Re: Auto-sensing for IPS devices Packet Man (Sep 19)
- Re: Auto-sensing for IPS devices Joel M Snyder (Sep 19)
- <Possible follow-ups>
- Re: Auto-sensing for IPS devices gmail (Sep 14)
- RE: Auto-sensing for IPS devices McKinley, Jackson (Sep 16)
- Re: Auto-sensing for IPS devices Sap . (Sep 16)
- Re: Auto-sensing for IPS devices djmeier (Sep 22)
- Re: Auto-sensing for IPS devices Lachlan Bowes (Sep 14)