Tag: Network

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GNS3 Network Simulator

Found something really cool today 🙂

GNS3 is a graphical network simulator where you can set-up complex virtual networks and run Cisco and Juniper routers or switches. The best is that you can also integrate Qemu and Virtualbox into your virtual lab environment what I really love. You can easily test new configurations on devices without having to set-up all these in hardware.

The only little problem is that you need a quite power system to do all of that. Otherwise I tested GNS3 on an 3 year old laptop with Intel Core2Duo and 4 GB RAM and run up to 6 Cisco routers without any big problems what’s enough for me at the moment.

Ah I forgot, you can of course also use Wireshark to capture packets on an link between two devices.

Here the link to the website: www.gns3.net

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F5 Load Balancer

My company decided to buy two F5 Big IP Local Traffic Manager 8950 for our web cluster systems with a maximum balanced capacity of 20 gigabit. We also got the F5 Local Traffic Manager as Virtual Edition for our test enviroment and to integrate it into the test network.

In the beginning the F5 looked very complicated but after some time now playing around with it and setting up things, it got easier and easier. I only need to have a deeper look at the iRules because this feature allows you can to really do everything with the F5 load balancer.

So for now I can’t really write more about it but I will soon  post some updates.

Next week I have the integration of the F5 Big-IP into the production network of my company and will start setting up the first new linux web cluster but only with a layer 4 balancing.

Update:

Here a nice picture of the new F5 BigIP boxes in the data center from my company:

For the new web cluster for my company we set-up layer 4 balanced web server pools and layer 7 balanced pools.

The layer 7 balancing was necessary because there where different server pools with applications that needed to run under the same domain and where routed on the expected http/https request. I will post the iRule for everybody soon.

Here two interesting ressources to get information:

Ask F5

F5 Devcentral

 

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Just tested new Cisco ASA 8.3 (Update)

It was a big suprise that Cisco changed so many things in the new IOS version for the ASA. Remember it is only an minor release update i would expect these changes for an major update but anyway they did a good work.

The new group objects what they implementent is very nice. It make the work much easier and you have a better overview about the NAT configuration like before because they move it to the actual network object.

Here an example how nat works in the network object:

object network web-01-external
host 24.0.0.1
exit

object network web-01-frontside
description Web Server Node 1
host 10.1.0.1
nat (inside,outside) static web-01-external
exit