Defensive Strategies

## Summary

Maintaining the network is a pivotal part of progressing as a hacker. Intrusions could come at any time, and in many forms, making defending against them a constant challenge. However, designing a well-crafted layout based on long-term goals, effectively placing nodes and implementing chokepoints, and understanding the weaknesses of stealth will provide the necessary tools to outperform the competition.

## Network Layouts

There are several commonly used layouts, each with distinct strengths and weaknesses. The following list provides a summary of these layouts and provides tips and tricks.

#### Chunk

All nodes are intertwined into one large chunk, with as many connections as possible.

* Pros
	+ Sentry antivirus spreads quickly throughout the network
	+ Confusing for attackers, as it will be hard to find best way through
* Cons
	+ Difficult to place netConnections nodes wisely
	+ Weak against stealth attacks, since there is often a way to install Portal in the middle of the network, or Wraith the primary defenses
	+ Weak to Shuriken and Shocker assaults

#### Maelstrom

An advanced version of the Chunk layout, with extensions on either end of the cluster to distance the resources and/or Core from the netConnections. Maelstroms function best with a high level Sentry and Core, enabling an increased number of low level nodes on the network.

* Pros
	+ High Sentry damage quickly recaptures low firewall nodes forcing attacker to have faster reaction while hacking
	+ Attackers must react quickly and multitask to avoid losing nodes repeatedly
	+ Nodes are difficult to target efficiently for Beam Cannon / Blaster.
* Cons
	+ Multiple paths give the defender little control of exactly how the attacker progresses
	+ All of the above weaknesses of Chunks

#### Snake

Oblong shaped network with all netConnections on one end and the Core and resources on the other. Nodes in the middle are surrounded by Security Nodes in order to slow down progress of attacker. This design especially works well for 2-18 lv where people have not been developed Wraith or Kraken yet.

* Pros
	+ Good against Brute Force attacks, especially with Code Gates along the middle
	+ Attackers may run short on programs by the time they reach the crucial end nodes
* Cons
	+ Vulnerable against Krakens heading straight for the Core
	+ Weak against Wraith attack as it will cut the spreading anti-virus throughout the network.
	+ Each segment can be taken methodically one at a time, allowing attackers with strong programs to consistently complete a successful hack, given enough time and enough program space for attackers.
	+ Weak against Shuriken as it will be able to bypass choke point very fast to advance.

#### Braid

An advanced version of the Snake layout, with surrounding Security Nodes linked crosswise to create multiple paths. Like Maelstroms, these are designed to keep intruders from gaining a substantial foothold.

* Pros
	+ Attackers must react quickly and multitask to avoid losing nodes repeatedly
	+ Sentry antivirus can spread more quickly than in Snakes, though not as quickly as in Chunks
* Cons
	+ Chokepoints are difficult to implement successfully
	+ Much more difficult to place Code Gates effectively than in Snakes

#### Tree

A branching network, with each branch extending into further, smaller branches. The "root" contains all the netConnections. The Core and other Business nodes are distributed among the different branches.

* Pros
	+ Challenging to compromise the whole network - more programs and time are required to reach all branches
	+ Chokepoints are numerous and easy to implement
	+ Many nodes can be kept far from the netConnections at the ends of the branches
* Cons
	+ Attackers can focus on a single branch to download the Core or part of the resources
	+ Weak to Shurikens

#### Ring

An advanced version of the Tree layout, designed to divide the attackers forces and attention. Although there are generally fewer branches, all are connected at the end, with security balanced among them. Like Maelstroms, these are particularly dependent upon sentries, and optimally have lots of low firewall nodes. Rings often have several smaller loops integrated into one or two larger ones.

* Pros
	+ Can mitigate the effectiveness of Kraken attacks as compared with Snake layouts
	+ Attackers are forced to take on all branches simultaneously to avoid losing nodes repeatedly, which requires focus and speed
	+ Many nodes can be kept far from the netConnections in the convergence at the end
* Cons
	+ A high level Core is generally required to have sufficient nodes for a successful Ring
	+ Can be difficult to place Code Gates effectively

Networks to not have to conform to a single design style, and using a hybrid of these layouts can help minimize the weaknesses of specific layouts, with the benefits of having a specific network type being reduced. For example, a Snake with a defensive chunk greatly increases the effectiveness of sentries, but reduces the length of the overall Snake at earlier levels. Redesigning the network at least occasionally is also key to taking advantage of the changing circumstances at different levels and ranks.

### Layout Goals

Any of the designs above can also be adjusted to serve various purposes, depending upon the interests and goals of the administrator:

* **Resources:** The Core is generally placed near or on a netConnection to nullify use of the Kraken. Since Databases and B-coin Mixers are often high level, they can be connected to chokepoints with Guardians behind them to drag out their capture. Snakes and Rings work well, since Full Control is almost necessitated, and many hackers will opt for an easier target.
* **Reputation:** The Core must be well defended and away from any netConnections, often protected by triple Guardians. Although resources may not be as valuable, at least some must be kept safe so it is difficult to Loot all Resources. Maelstroms and Trees work well, since Full Control is difficult and hackers only interested in resources may be dissuaded from completing any of the win conditions.
* **Hacking:** While this generally implies the need for resources, these are regularly attained in the process of hacking, and the administrator may want to lure hackers into looting so as to retrace the attack. Reputation may also be desired to find more challenging targets, but otherwise the Core is usually left near or on the netConnections. Chunks and Braids work well, depending on the added level of interest in resources, reputation or personal satisfaction.

## Node Placement

A much more effective network can be designed by understanding and using the attack priorities that are followed by various programs. If connected nodes fall under the same category, nodes will be attacked in the same order in which they were connected.

Effective placement of nodes will further enhance the strength of the network. Following these general guidelines will help:

netConnections

* Strong when connected with low value Hacking Nodes (such as compiler, program library or evolver)
* Weak when connected to Security Nodes, since netConnections cannot be recaptured

Core - The placement of the Core depends on interests and goals

* Place it as far from any netConnections as possible to maintain Reputation and find more challenging networks
* Place it near a netConnection to help preserve Resources and lure in targets to retrace

Sentry, Turret and Black ICE

* Strong when connected to other Security Nodes
* Weak when too close to a netConnection, or connected to very few nodes

Scanner

* Strong when within range of Code Gates, resource storages or collectors, or the Core
* Weak when near a netConnection or in front of Code Gates

Code Gate

* Strong when only a single node can attack it
* Weak when approachable from multiple nodes or when there are alternate paths to avoid it

Guardian

* Strong when placed behind high firewall nodes
* Weak when connected to few nodes or placed in front of connecting nodes

### Chokepoints

Chokepoints are nodes designed to be especially pressured by network security. The optimal chokepoint has low firewall, few program slots, many connection slots, and is connected directly in front of several security nodes, or nodes which take considerable time to capture.

The Evolver makes for a consistently good chokepoint, with Scanner and Compiler nodes also performing well at both low and high levels. Resource nodes, Program Libraries and Guardians scale well at higher levels, due to the slower rate of firewall growth compared to other nodes.

### Defending against Stealth

When a stealth hack is started, Security Nodes do not activate immediately. The Access program installs in only one second, then granting access to all connecting nodes. High level stealth programs can easily cripple network security without good defenses against them. These consist of Scanners and Code Gates.
Scanners multiply the visibility of every program installed within three nodes by the sensitivity statistic. Upgrading it and placing it effectively will greatly limit the number of stealth programs an attacker can install, and how much damage can be done before the main timer starts. Try to position them directly behind a Code Gate or series of Gates.
Code Gates greatly increase the amount of time required to install Access, based on the filter statistic. A Wraith can disable it, but even that will cost considerable additional visibility, disk space, and has a high compilation time and cost. Try to restrict the paths through the network in order to force attackers through the Gates.

Lastly, the best way to defend the most important nodes is by placing them as far from the netConnections as possible, and distracting programs toward other nodes by exploiting attack priorities.

## Tips

* While you are online, you can not be hacked for the first 3 hours of a session. However, if you are playing continuously for more than 3 hours, other players will be able to connect to your network and you will receive a message that your network has been hijacked by another player.
* Experiment with various network layouts.
* Redesign your network from time to time. What works well against low level attackers will usually not work at level 35 or 55.
* Replay successful hacks to your network in the Security Log to see how your defenses were compromised and find your weak points.

## Notes

1. ↑ 1.0 1.1 Chokepoint scoring was calculated by dividing average firewall by specific firewall and program slots, then multiplying by connection slots and a factor of 10 (for easy comparison)

Level 1 formula:

(
1000
×
C
)

(
F
×
P
)

{\displaystyle \tfrac{(1000 \times C)}{(F \times P)}}

            Max Level formula:

(
10000
×
C
)

(
F
×
P
)

{\displaystyle \tfrac{(10000 \times C)}{(F \times P)}}

Where C = Connection Slots, F = Firewall, and P = Program Slots

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