IT Security & Network Engineering Knowledge Base

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Brocade ADX – How to tune/configure the TCP stack

Introduction There are 2 main methods for configuring the TCP stack on an ADX, globally or via a tcp profile. Within this article we will look at the main configuration settings available, such as how to configure Nagle, SACK and Window Scaling. TCP Profiles TCP profiles allow you to modify the TCP parameters on a … Read more

Python 2.7.5 : ImportError: No module named _sqlite3

After compiling Python 2.7.5 you may find yourself being unable to to import sqlite3 and receiving the following error message, ImportError: No module named _sqlite3 Solution Install sqlite-devel via ‘yum install sqlite-devel’ Recompile Python. Note : Details on how to compile Python can be found within the following article.    

Where are Certifcates located within BigIP F5 v11.x ?

Within v11.x of LTM/GTM BigIP certificates are located within a folder called ‘certificate_d’ under the necessary partition folder. i.e /config/filestore/files_d/Common_d/certificate_d By default everything is placed within the common partition folder ‘Common_d’. Below shows an example root@gtm:Active:Standalone] # ls -l /config/filestore/files_d/Common_d/certificate_d total 32 lrwxrwxrwx 1 root root    33 Sep 30 02:52 :Common:ca-bundle.crt_1 -> /config/ssl/ssl.crt/ca-bundle.crt lrwxrwxrwx 1 … Read more

TCL – The difference between the eq and == operators

TCL Background Unlike many programming languages (such as Python) TCL stores all values as strings. By using operators or commands these values can be interpreted as different data types (such as integers, binary etc). ‘eq’ vs ‘==’ Though, on the surface, the 2 TCL operators ‘eq’ and ‘==’ appear similar, ie  both return a boolean … Read more

BigIP F5 LTM: Application Visibility & Reporting (Analytics)

Summary Introduced within TMOS 11.0, AVR (Application Visibility and Reporting) allows you to gather statistics on the performance of applications, such as pool members, virtual servers etc. From within these statistics, analytics such as latency, response times and throughput (to name but a few) can then be viewed either via either the WebUI or the … Read more

Brocade ADX: Show CPU usage for Management Processor

Question How do I show the CPU usage for the management processor ? Answer To see the CPU usage on the MP (Management Processor) the following command is used, SSH@adx# show cpu-utilization peak: 41.4 percent busy at 5520 seconds ago 7243 sec avg: 10.3 percent busy    1 sec avg:  1.0 percent busy    5 … Read more

Vyatta – How to Configure a Remote Access VPN

Purpose The purpose of this document is to explain the various steps required in configuring a remote access VPN on a Vyatta appliance. Vyatta Configuration The Vyatta configuration steps are pretty straight forward. You enable the outside interface with IPSEC, the IP pool, along with the secret passphrase and usernames and passwords, then your good … Read more

Brocade ADX – The CSW Pseudo Stack

Purpose The purpose of this document is to explain the role and functions of the CSW Pseudo Stack. Summary Within the Brocade ADX feature set is the ability to forward traffic based on layer 7 attributes (such as host header, URI etc.). This is achieved by enabling content switching (CSW). In order for the the … Read more