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New Member

Interface speed/duplex settings in 4.0 sensors

How do you configure sensing interface settings in 4.0 sensors? In 3.0, you could vi the /kernel/drv/e1000g.conf file to facilitate the setting of the interface. There is nothing in VMS which lets me configure speed or duplex. I've tried the CLI and have only gotten this far.

"configure terminal"

"interface sensing <name>"

I've tried "IntelPro" for the name, as it appears the sensing interface is named from the status. What am I doing wrong?


Chris Schear


Re: Interface speed/duplex settings in 4.0 sensors


The following link gives the commands requiered for 4.0 sensor.

Hope this helps.

New Member

Re: Interface speed/duplex settings in 4.0 sensors

I appreciate the response, but therein lies the problem. The defined configuration parameters do not account for speed or duplex settings. It's a linux OS, there is most certainly the capabilities to configure such parameters, it simply appears Cisco did not account for such configurations within the CLI. Unless, it's in some other location or through some undocumented commands.

New Member

Re: Interface speed/duplex settings in 4.0 sensors

It is possible to hard code these settings in CIDS 4.0(1), but it is not recommended. Your changes may also be lost each time you reboot beginning with the 4.0(2) service pack.

You can modify /etc/modules.conf to set speed/duplex for the e1000 driver by adding Speed and Duplex options as indicated in the following example:

alias eth0 e1000

alias eth1 e1000

options e1000 Speed=10,100 Duplex=2,1

Valid settings for Speed are 0 (auto), 10, 100, or 1000. A setting of 10 or 100 requires Duplex also be set. When Speed is set to 1000, limited auto-negotiation is enabled and only 1000 Mbps is advertised (The 1000BaseT spec requires auto-negotiation).

Valid settings for Duplex are 0-2 (0-auto-negotiate, 1=half, 2=full). NOTE: If the link partner is forced (either full or half), Duplex defaults to half-duplex.


- These settings work for adapters using copper connections only. They will be ignored for fiber connections, which will only link at 1000 Mbps full-duplex.

- A separate entry must be made for each interface using the e1000 driver. In the example listed above, a system with two e1000 interfaces is configured with eth0 set to 10 Mbps full-duplex, and eth1 set to 100 Mpbs half-duplex.

The e100 driver can be modified in a similar manner, but the option for this driver is "e100_speed_duplex".

Valid settings for e100_speed_duplex are 0-4 (0=auto-negotiate, 1=10half, 2=10full, 3=100half, 4=100full). A separate entry must be made for each e100 interface in the system as demonstrated in the example below:

alias eth0 e100

alias eth1 e100

options e100 e100_speed_duplex=2,3

In this example, the system contains two e100 interfaces, eth0 and eth1. Eth0 is set to 10full, and eth1 is set to 100half.

*** WARNING ***

Do not change any other settings in /etc/modules.conf.

Hard coding of speed/duplex on the network interfaces has not been fully tested, and is not supported on the IDS appliances. If you encounter problems with your IDS appliance after making changes to the configuration, the TAC will require a full system recovery before they attempt to troubleshoot any system problems.


New Member

Re: Interface speed/duplex settings in 4.0 sensors

Is there a way to configure the sniffing interface (v3 or v4) to support a trunk interface, ie connected to a dot1q trunk on the switch.

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