Not usually.
It sounds like something is not happening correctly.
When the IDS creates a new ACL it also does a write mem so if the router reboots it shoudl come back up with the same access lists that were last written by the sensor.
We have seen cases where the write mem on the router was generating errors (seen when the ACLs were too large to be saved properly, or when other users were also making changes on the router). In which case the router may be rebooted and come up with invalid config.
The other possibility is that the sensor is not using the correct permit line in the first ACL entry. The first permit line should permit the sensor itself to access the router.
If there is no NATing between the sensor and router then the sensor shoudl eb permitting the actual sensor ip address.
If on the other hand there is NATing between the sensor and router then the sensor will need to permit this NAT address. To do this the user has to tell the sensor what it's NAT address will be when connecting to that router.
Some users have confused that NAT field above with the NATing being done by the router itself.
This NAT field is NOT the NAT address being used by the router, but is INSTEAD the NAT address being used by a router or firewall between the sensor and router.
If the wrong address is being entered into this NAT field, it is possible that the first line of the ACL that permits only the NAT address maybe unexpectedly denying the sensor's address and preventing the sensor from continuing it's connection to the router.
Marco
