Currently viewing the tag: "tcp"

Cisco: Multiple Vulnerabilities in Cisco PGW Softswitch

By On May 17, 2010 · 1 Comment

Multiple vulnerabilities exist in the Cisco PGW 2200 Softswitch series of products and they are related to processing Session Initiation Protocol (SIP) or Media Gateway Control Protocol (MGCP) messages.

SIP is a popular signaling protocol used to manage voice and video calls across IP networks such as the Internet. SIP is responsible for handling all aspects of call setup and termination. Voice and video are the most popular types of sessions that SIP handles, but the protocol is flexible to accommodate for other applications that [...]

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Great tool for testing QoS implementation

By On December 16, 2009 · 5 Comments

After my last post, some readers were asking what tool did I used for testing the QoS and how satisfied I’m with it.

The name of the tool is Packgen. According to its developer developers, “Packgen is a simple network packet generator handling diffserv markers, useful for testing network bandwidth and QoS.” It support features like:
– Network packet flows generation with given bandwidth (packets sent at each time interval depending on the bandwidth to produce and the [...]

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Cisco: DoS protection using TCP Intercept

By On May 19, 2009 · 2 Comments

Every now and then, all network engineers have to deal with some kind of network attack.  Usually, the attack does not target the network devices, but the machines that provide services (e.g. www, database hosting…), because it’s more easy to find on the Internet a script that is probing port 80 for example, which by the way any kiddie can use, than to corrupt BGP in order to act as man-in-the-middle. Anyway, in front on the machine being attacked, there is a network device and [...]

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Cisco hidden tools: Testing TCP connection

By On November 12, 2008 · 1 Comment

Sometimes you have a connection between 2 routers that you want to test with something more than a ping. Cisco devices have a hidden command which is actually a very powerful testing tool for your TCP connection.

The command is “ttcp” and you will not find it in the the default list of commands of a Cisco device. So, even if you use help ( “?” mark at the router prompt) this command will not be showed to you.

For our testing we will use [...]

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