What are the signatures of malformed packets that misuse the SYN and FIN flags? Briefly describe each.
What will be an ideal response?
SYN FIN is probably the best-known illegal combination. Because SYN is used to start a connection and FIN is used to end one, it does not make sense to include both flags together in a packet.
Other variants of SYN FIN exist, including SYN FIN PSH, SYN FIN RST, and SYN FIN RST PSH. Their use is sometimes called an Xmas attack. These packets can be used by attackers who know that IDPSs might be looking for packets with just the SYN and FIN flags set.
Packets should never contain a FIN flag by itself. FIN packets are frequently used for port scans, network mapping, and other stealth activities.
A SYN-only packet, which should occur only when a new connection is being initiated, should not contain any data.
You might also like to view...
What particular type of group should you create in Server Manager if you have dozens or even hundreds of servers to manage?
What will be an ideal response?
A principle stating that data is organized in tables so that there is no redundant data.
The action of canceling the selection of an object or block of text by clicking outside of the selection is called:
A. click B. point C. deselect
Answer the following statement(s) true (T) or false (F)
1. Communication with an Ethernet device using Ethernet communications is not possible until the device is configured and/or the IP address for the device is known. 2. The 1769-L23s are available with embedded ControlNet communications. 3. All 1769 CompactLogix controllers are supplied with one serial and one Ethernet port. 4. DeviceNet communications require the separate purchase of the communications modules for insertion into a CompactLogix slot. 5. The CompactLogix Ethernet/IP address changes frequently after installing a network and configuring other devices on the network.