2. Network

Web Security Manager can block hostile IP addresses at the network level. Addresses can be learned and automatically blocked in four different ways.

  1. DoS Mitigation

    If DoS Mitigation is enabled source IPs exceeding configurable request limits are automatically blocked for a configurable number of seconds (i.e. 86400 - 24 hours).

  2. Attack source auto blocking

    If Attack source auto blocking is enabled source IPs are tracked across all website deny logs. If a number requests above a certain risk level are recorded within a certain time span the source IP is automatically blocked for a configurable number of seconds.

  3. Immediate source blocking.

    Each website can be configured to immediately block a source IP if a log event above a certain risk level is recorded.

  4. Manual entry

    IP addresses can be added manually to the list of blocked source IPs.

Only traffic to inbound interfaces is blocked. Management interfaces are not blocked unless the management role has been bound to an interface which is also responding to inbound requests - typically the interface facing the Internet.

Blocking a source IP does not keep a determined attacker from accessing your website. Positive filtering at the application level, which is the core functionality of Web Security Manager is much better at stopping unauthorized intrusion attempts. It does however make it more difficult, especially if immediate source blocking is enabled as this will force the attacker to change IP every time he triggers an attack signature.

2.1. Blacklisted Source IPs

The table shows which source IPs are currently blocked.

Source IP

Source IP

Violation

The reason for / type of blocking. Can be:

DoS

The source IP has triggered the DoS mitigation by issuing too many requests within a too short time span.

Policy

The source IP has either triggered the general attack source auto blocking or a website specific block-IP policy.

Permanent

The source IP has been added to the list manually.

Attacks

Total number of attacks recorded from country/IP.

Click row to zoom in on attacks.

Added

Date and time the source IP was added to the list.

Blocked packets

Number of blocked packets from the source IP

Blocked bytes

Number of blocked bytes from the source IP

Del

Button

Remove IP from the list.

2.2. Network blocking bypass

The table shows IP addresses which are allowed to bypass network protection like blacklisting and DoS mitigation controls.

Trusted Client Source IP

The IP address which will bypass network controls.

In packets

Number of incoming packets from the source IP

In bytes

Number of incoming bytes from the source IP

Out packets

Number of outgoing packets to the source IP

Out bytes

Number of outgoing bytes to the source IP

2.2.1. Allowing an IP address to bypass network controls

The network blocking bypass white list is compiled of

  1. the website trusted client lists,

  2. the website trusted proxies,

  3. the default gateway.

Website trusted client lists

IP addresses are added in Services->Websites+Policy->Website global policy+Trusted clients and network blocking bypass for trusted clients has to be checked in Services->Websites+Policy->Website global policy+IP pass through. In addition network blocking bypass has to be enabled in general (below).

Website trusted proxies

Trusted proxies are added in Services->Websites+ADC->Virtual host+Trusted Proxy.

The default gateway

This is enabled by default.

Note that this feature is only available on WAF licenses.

Allow website Trusted Client IPs to bypass network protection

Check box

Enable / disable network blocking bypass for trusted clients.

Default: <disabled>

Allow trusted proxy IPs to bypass network protection

Check box

Enable / disable network blocking bypass for trusted proxies.

Default: <disabled>

Allow gateway IP to bypass network protection

Check box

Enable / disable network blocking bypass for the default gateway.

Note that this will not allow requests passing through the default gateway but only requests with the default gateway as source.

Default: <enabled>

2.3. DoS mitigation

When enabled the DoS mitigation system tracks source IP connections to inbound interfaces. If an IP exceeds the configurable limits it is added to the list of blocked IPs and further connection attempts are silently dropped at the network level.

Enable DoS mitigation

Check box

Enable / disable DoS mitigation.

Default: <disabled>

Max src conn

Input field

Limit the maximum number of simultaneous TCP connections which have completed the 3-way handshake that a single host can make.

Valid input

Any integer

Default value

<30>

Max src conn rate

Two input fields: number and seconds.

Limit the rate of new connections to a certain amount per time interval.

Valid input

Both fields take an integer as valid input.

Input example

50 / 5 - 50 connections in 5 seconds

Default value

<60 / 10>

Blacklist IPs for

How long time IPs should be blacklisted in seconds.

Valid input

An integer

Input example

<36000> - 10 hours

Default value

<86400> - 24 hours

IPs are automatically removed from the list when the blacklist period has ended.

2.4. Attack source Auto blocking

Attack source auto blocking tracks denied source IPs at the application level and blocks an IP at the network level if they reach configurable limits.

Enable Attack Source Auto Blocking

Check box

Enable / disable Enable Attack Source Auto Blocking.

Default: <disabled>

Attack threshold

Input field

Sets the maximum number of denied requests across all websites within a certain time frame (below).

Only websites with source tracking enabled contribute to the attack threshold number and for each website a risk threshold is configured above which denied requests are added to this global counter.

Valid input

Any integer

Default value

<5>

Time threshold

Input field

Sets the time frame within attack threshold (above) is accepted.

Valid input

Any integer

Default value

<86400>

Blacklist IPs for

How long time IPs trigging the Attack source Auto blocking should be blacklisted in seconds.

Valid input

An integer

Input example

<86400> - 24 hours

Default value

<604800> - 1 week

IPs are automatically removed from the list when the blacklist period has ended.

© 2005 - 2012 Alert Logic inc.