09-28-2009 10:29 PM - edited 03-10-2019 04:46 AM
I would like to issue TCP resets thru promiscuous interface of cisco IPS 4240. As per the current setup (which is explained in the attached drawing) there is only one vlan between firewall and switch and its working fine with following configurations in switch
monitor session 1 source interface fastethernet0/5
monitor session 1 destination interface fastethernet0/14 ingress vlan 145
My problem is, if we have multiple vlan in between switch and firewall. How the configuration should be? any extra configuration required in IPS as well?
09-30-2009 07:11 AM
On the switch, instead of using interface as the monitor source, use VLANS and in the monitor destination any one vlan is required.
The IPS will send the TCP RST packet via that vlan.
monitor session 1 source vlan 145,146,147
monitor session 1 destination interface f0/14 ingress vlan 145
There is no change on the IPS.
09-30-2009 09:03 AM
You are limited to only sending TCP resets to one VLAN when you send them out the sniffing interface.
09-30-2009 06:23 PM
Can I know why we are using vlan 145 after ingress command.
10-02-2009 10:56 AM
vlan 145 is used after ingress command because the IPS will send the TCP RST packet via that vlan.
10-02-2009 11:37 AM
Is that because, a tcp reset will be sent to vlan 145 against any traffic without a vlan tag.
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