Iwan Hoogendoorn

Hi,

Today I am going to tell you guys something about 2 tools that was developed by Cisco (or at least developed for Cisco)

Before I am telling anything about these tools I need to say cannot provide any of these tools and I will not provide any information on how you can get these tools.

The first tool is called IOU.
The second tool (that exist of a set of around 16 tools) is called Pagent.

IOU which basically means “IOS on Unix” is a tool that can simulate multiple router instances.

Pagent is based on the Cisco IOS (Internetwork Operating System), and developed within Cisco. The test tools are included in special IOS Pagent images.

IOU
IOS on Unix is a fully working version of IOS that runs as a user mode UNIX (Solaris) process. IOU is build as a native Solaris image and runs just like any other program on Solaris. IOU supports all platform independent protocols and features. It is possible to connect multiple copies of IOU trough the network to form some kind of virtual network.
This way you can build a bigger network using multiple Sun Ultrasparc machines.
There is also a version that runs on OSX (Mac) but I don’t know much about this version. It’s probably the same as the Solaris version but especially for Mac.
What is also nice to know is that there are IOU images available with the Pagent software build in.
Nowdays there is a programs like Dynamips, Dynagen and GNS3 doing the same IOU is doing.
Cisco employees (engineers) are using IOU to test complex designs and features in order to support large customers.

Pagent
The primary function of the Pagent tool set is to provide cost effective test tools to the Cisco community. This tool is NOT available for the public and requires a serial number based on the hardware serial number. There are some cracked versions available out there on torrent websites but this will not be the scope of this blog.

Since the tools are based on production hardware and the IOS operating system, the tools are not able to test the datalink level. They cannot affect frame checksums, preambles, inter frame gap times, or inject hardware failures.
There are limitations to the rates that Pagent tools can transmit and receive packets. Due to the processing power of the main CPU, not all IOS based devices are able to transmit packets at full media rates.

The Pagent programs are best used for testing layer 3 protocols and above. That is, emulating routing
protocols, multicast, TCP sessions, HTTP sessions. Pagent images have a security scheme to prevent illegal distribution outside Cisco. When an router is loaded with a Pagent image for the first time, it presents a machine Id that must be converted to a license key. Once the license key is entered in the router, it is saved in the configuration so it is not required on subsequent downloads.

Pagent tools
• TGN (Traffic Generator) is used to define and send packets on any combination of supported
interfaces on a router. The program has predefined templates to support the definition of specific
packet types. Packet lengths and the data in any header field can be set to constant, incrementing
or random values. Packet definitions can be imported from the PKTS program capture buffer.
• PKTS (Packet Count and Capture) can capture and display incoming and/or outgoing packets from
any combination of interfaces on a router. It can fast-count packets, that is, it can count and discard
packets at higher rates than IOS counters can support. PKTS supports the creation of filters that
allow selective counting, capture or display
• Template Compiler provides a convenient high-level language for defining packet formats. It adds
new packet definitions to the Pagent tool set (TGN and PKTS) at run time and allows TGN traffic
streams and PKTS filters to be defined using the new formats. It allows the definition of multiple
display methods that can be used to decode and display packets.
• Router Verified Traffic (RVT) and Control Verified Traffic (CVT) are used together to test bridges
and routers. CVT can automatically create numerous traffic streams between many Pagent router
interfaces, for many different LAN media and network protocols. RVT can create modest levels of
verified traffic where every packet sent through the test network is validated for correct sequence,
data integrity, and length. RVT can also create fast-unverified traffic.
• PMOD (Passthru Modify) allows a Pagent router to be inserted into a test network so test traffic
passes through the router and then allows the traffic packets to be modified. Depending on PMOD
filters and configurations, the tool can selectively drop, alter, delay or timestamp packets. It also
allows test packets to act as triggers and can recalculate test packet IP, TCP and UDP checksums.
• TCP Session Emulator (TCPSE) is a tool for generating TCP traffic. The tool provides configurable
features that enable a user to emulate various TCP application dialogs between a TCP client and a TCP server. It emulates multiple hosts establishing thousands of TCP connections. All these TCP sessions are short-lived, which is very typical for web or email traffic.
• HTTP Session Emulator (HTTPSE) is a tool for generating HTTP traffic. It emulates multiple
HTTP clients establishing HTTP connections to a HTTP server. It generates all kinds of HTTP
traffic, including all kinds of HTTP requests and HTTP responses.
• FTP Session Emulator (FTPSE) is a TCP application for transferring files. The FTPSE Client
Emulator generates real FTP traffic and emulates FTP client sessions, which must talk to a real
FTP server. Currently FTPSE only supports the client side in passive mode.
• Large Network Emulators (LNE) is comprised of six programs to support six routing protocols:
BGP, OSPF, ISIS, EIGPR, IGRP and RIP. LNE is used to emulate routers that advertise large router
networks. It can emulate hundreds of routers to emulate multiple peers to a router under test. To
stress the router under test, LNE can flap entire LNE routers, routes advertised by the LNE routers
or route attributes.
• NQR) is , a tool to measure end-to-end network delay, jitter, packet drop, and out-of-sequence packets.

Next time I am going to go deeper into the pagent tools and I am going to give examples how LNE, TGEN, PKTS and much more is working.