Yazar: nurettin alp

DNS Rebinding Protections

pfSense includes two built in methods of protection against DNS rebinding attacks. These measures are described below.
DNS forwarder

The DNS forwarder (dnsmasq) uses the option –stop-dns-rebind by default, which rejects and logs addresses from upstream nameservers which are in the private IP ranges. In the most common usage, this is filtering DNS responses you’re getting from the Internet to prevent DNS rebinding attacks. Internet DNS responses should never come back with a private IP, hence it’s safest to block this.

Note this is automatically overridden for domains in the DNS forwarder’s domain override list, as the most common usage of that functionality is to resolve internal DNS hostnames.
Web interface protection

For those not using the DNS forwarder and already having that protection, and as an additional layer of checks, the web interface will block attempts to access it via an unknown hostname. It will display “Potential DNS Rebind Attack Detected” and drop any request. By default, only the hostname and domain configured under System>General Setup are accepted. For instance if you have firewall.example.com configured as your system’s hostname, and you try to browse to it using fw1.example.com, that attempt will be rejected. You can add additional hostnames under System>Advanced, “Alternate Hostnames”.

Note you can log in using the IP address of the system rather than the hostname should you find yourself unable to log in with this message. Then configure the hostname(s) accordingly and you will be able to log in using the hostname

http://pyload.org/
flashgot

sudo update-alternatives --config x-www-browser

If we add the repository http://www.debian-multimedia.org on Debian testing
it can happen that when we try to execute the comand apt-get update, we see a GPG error:

W: GPG error: http://www.debian-multimedia.org squeeze Release:
The following signatures couldn’t be verified because the public key is not available: NO_PUBKEY 07DC563D1F41B907

To solve this problem we need to install the debian-keyring package

# apt-get install debian-keyring

And then execute this command:

# gpg –keyring /usr/share/keyrings/debian-keyring.gpg -a –export 07DC563D1F41B907 |apt-key add –

After that, when we try to execute apt-get update, there will be no the GPG error anymore.

http://en.wikipedia.org/wiki/Direct_inward_dialing

Direct inward dialing
From Wikipedia, the free encyclopedia
Question book-new.svg
This article does not cite any references or sources. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. (December 2007)
Direct inward dialing (DID), also called direct dial-in (DDI) in Europe and Oceania, is a feature offered by telephone companies for use with their customers’ private branch exchange (PBX) systems.
The term DID originated in conventional telephony, where it allowed an individual extension on a private branch exchange to be reached directly via its own standard outside number. In modern usage, voice-over-IP providers commonly refer to individual numbers provided to their subscribers as DIDs.
Contents [hide]
1 Plain old telephone service
2 Use in FAX services
3 Voice over Internet
4 Sellers
5 Direct outward dialing
6 See also
Plain old telephone service[edit]

In DID service the telephone company provides one or more trunk lines to the customer for connection to the customer’s PBX and allocates a range of telephone numbers to this line (or group of lines) and forwards all calls to such numbers via the trunk. As calls are presented to the PBX, the dialed destination number (DNIS) is transmitted, usually partially (e.g., last four digits), so that the PBX can route the call directly to the desired telephone extension within the organization without the need for an operator or attendant. The service allows direct inward call routing to each extension while maintaining only a limited number of subscriber lines to satisfy the average concurrent usage of the customer.
Traditionally, DID circuits were analog. These types of DID trunks had to be powered by the customer premises equipment. The central office equipment detects the power state of the line and disables service if the circuit is not powered up. This is the reverse arrangement from standard plain old telephone service (POTS) lines which are powered by the central office. Nowadays, it is far more common to deliver DIDs on a PRI circuit.
In the United States the feature was developed by AT&T in the 1960s, patterned upon the earlier IKZ service of the Deutsche Bundespost.
DID service is usually combined with direct outward dialing (DOD) allowing PBX extensions direct outbound calling capability with identification of their DID number.
Use in FAX services[edit]

This system is also used by fax servers. A telephone line is terminated in a computer running fax server software and fax modem cards. A set of digits of the assigned phone numbers are used to identify the recipient of the fax. This allows many recipients to have an individual fax number, even though there is only one fax machine available.
Voice over Internet[edit]

Direct inward dialing service has similar relevance for Voice over Internet Protocol (VoIP) communications. To reach users with VoIP phones, DID numbers are assigned to a communications gateway connected by a trunk to the public switched telephone network (PSTN) and the VoIP network. The gateway routes and translates calls between the two networks for the VoIP user. Calls originating in the VoIP network will appear to users on the PSTN as originating from one of the assigned DID numbers.
Sellers[edit]

In the United States, DID numbers and services can be purchased in bulk from a Competitive Local Exchange Carrier (CLEC). International DID numbers can be purchased in bulk from international providers. UK Geographic DID numbers can be obtained for free, terminated over SIP and also generate a revenue for inbound traffic.
Direct outward dialing[edit]

The corresponding service to DID for outgoing calls from a PBX to the central office exchange is called direct outward dialing (DOD) or Direct Dial Central Office (DDCO). This service is often combined with DID service and allows direct dialing of global telephone numbers by every extension covered by the service without the assistance of an operator. The caller line identification (CLI) or caller-id of extensions for outgoing calls is often set to the extension DID number, but may be the organization’s central switch board number.
See also[edit]

Dialed Number Identification Service
Dial plan

xfce gnomenin network-manager programını kulllanıyor.