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IDS with 2 ports

I have 4235 with two ports, i use one as controller and the other as sensor (IDS promiscious mode) but the quiestion is could i use the two ports as IPS (inline mode)

  • Intrusion Prevention Systems/IDS

Re: IDS with 2 ports

How are you planning on managing it?

Cisco Employee

Re: IDS with 2 ports

The base IDS-4235 appliance contains 2 interfaces.

1 interface is for management

the other interface is for sensing.

The management interface can ONLY be used for management. The user does not have the option of using this interface for monitoring. The software itself will prevent it.

So what are you alternatives.

With the 1 sensing interface you CAN still do inline monitoring. Instead of pairing 2 interfaces you would pair 2 vlans on the one interface. Attach the 1 interface to a switch and trunk 2 vlans. Then in the IPS configuration you pair these 2 vlans. The sensor will then do inline monitoring of traffic that it bridges between these 2 vlans. Since it is bridging and not routing, it is the same IP subnet that needs to exist in both of the vlans.

The other alternative is to purchase an additional card so you can inline interface pair monitoring. The IDS-4235 supports a single Gig TX card, and then you can pair the onboard sensing interface with the interface on the new card to create your inline interface pair.

Alternatively the IDS-4235 also support the 4FE card. With the 4 10/100 TX ports you have the option of creating 2 inline interface pairs.

(NOTE: only one card can be used in the sensor. So you would need to purchase either the single port Gig TX card, or the 4 port FE card; but you can NOT use both at the same time.)