Internet

For many years now, rumours about different kinds of network lag-attacks have circulated for a while and died only to be revived in a year or so.

This document will attempt to explain some concepts of internetworking and Internet security.

IP (Internet Protocol)

The Internet Protocol (IP) is the method or protocol by which data is sent from one computer to another on the Internet. Each host (computer, router etc) on the Internet has at least one IP address that uniquely identifies it from all other computers on the Internet. When you send or receive data (for example, receiving a long room description in MUME), the message gets divided into little chunks called packets. Each of these packets contains both the sender's Internet address and the receiver's address. Any packet is sent first to a gateway computer that understands a small part of the Internet.

The gateway computer reads the destination address and forwards the packet to an adjacent gateway that in turn reads the destination address and so forth across the Internet until one gateway recognizes the packet as belonging to a computer within its immediate neighbourhood or domain. That gateway then forwards the packet directly to the computer whose address is specified.

DoS (Denial of Service) Attacks

On the Internet, a denial of service (DoS) attack is an incident in which a user or organization is deprived of the services of a resource they would normally expect to have. Typically, the loss of service is the inability of a particular network service, such as MUME, to be available or the temporary loss of all network connectivity and services. Common types of DoS attacks are buffer overflow attacks and SYN-floods.

To be able to execute a DoS attack, you will need at least the IP-address of the target. Most likely a presumptive attacker would also want to know what OS the target is running, and - if possible - what kind of network the target is locally connected to.

MUME and DoS Attacks

Since MUME doesn't offer the players any way of knowing what IP-address any given player has, the possibility of DoS Attacks to gain advantage of an enemy etc is very limited. A presumptive attacker would need to take control of a host with a network device very close to MUME, and listen in on all network traffic. Then the attacker would need to filter out information about his/her enemy, and use some kind of attack-program to disable the target. Of course, this is in theory all very possible, but also VERY unlikely to happen.

If someone were to gain control of above mentioned host in the vicinity of MUME, he or she could do a lot worse damage than executing DoS Attacks on PK enemies.

PK and Lag

When going from a non-PK situation to a PK-situation, generally the textual output from MUME increases a lot. This means that even a low packet loss link gets a more notable latency (lag) when loaded with more packets. This lag is generally because of the resending (packet loss recovery) offered by TCP (Transmission Control Protocol), which is the transport layer above IP that MUME uses for player connections.

It might also be worth noting that having a 0% packet loss link when using a ping-program (a program that uses the ICMP echo-request and echo-reply messages), does not guarantee you will have 0% packet loss over a TCP session (such as a connection to MUME).