When doing any moderate to advanced networking, you are likely to have to deal with subnetting. While some people have an ability to do the binary math in their head to figure out the correct subnet-mask, I prefer to use a tool to give me the answer. I have used…
Create Random Passwords with Linux
When creating user accounts on servers and devices, it is important to use strong passwords that will be difficult to guess or crack. It is often preferred to at least create accounts with a random password, and allow the user to change it to something they can remember. A great…
Backup MySQL Databases Automatically on a Linux Server
Dumping a MySQL database to a file is not a difficult task, but it is nice to be able to automate the process and have several versions archived. There is a project called “AutoMySQLBackup” available at: http://sourceforge.net/projects/automysqlbackup/. First you should download the script to your Linux host using wget: host#>…
Switching from Cisco IOS DHCP to an external DHCP Server
My previous post about “Use a Cisco IOS Switch to Serve DHCP to Avaya Phones” was inspired by my need to quickly test connectivity with a remote site. The solution worked very well for us. Eventually we were able to deploy a server to handle all DHCP, and needed to…
Use a Cisco IOS Switch to Serve DHCP to Avaya Phones
Avaya VoIP phones require a special option in a DHCP scope, so they know how to make calls. There may be times where it is desirable to have the DHCP running on a piece of networking equipment on a remote site, so that a separate server is not needed for…
Configuring a VPN between a Juniper Firewall and a Cisco PIX
Juniper tends to have pretty good documentation in their knowledgebase, on how to configure equipment for different situations. I recently had to setup a VPN between a Juniper SSG-140 (at HQ) and a remote Cisco PIX. Going to Juniper's knowledgebase, you would most likely come across the article: http://kb.juniper.net/KB4147 .…
Create a VLAN Trunk between Cisco IOS and a Foundry BigIron
I previously posted on how to “Create a VLAN Trunk between Cisco CatOS and a Foundry BigIron“. During the same project I also had to create a trunk between Cisco IOS and a Foundry BigIron. Anyone who has used both CatOS and IOS know that there is a significant difference…
Compile and Install FreeSWAN on RedHat Linux 7.3
I had the need to install FreeSWAN on an old RedHat Linux 7.3 machine. While most people's initial reaction would be to upgrade the system, we all know this is not always an option. I initially tried to do a simple “rpmbuild –rebuild…” but that did not do the trick.…
Create a VLAN Trunk between Cisco CatOS and a Foundry BigIron
Unfortunately Cisco and Foundry disagree on the definition of a “trunk”. Awhile ago I had to find a way to trunk multiple vlans between a Cisco 5000 CatOS and a Foundry BigIron switch. I made a quick call to a Foundry Systems Engineer to find out what was needed to…
OSPF Issue with Nokia CheckPoint and Cisco 12.3
A Nokia CheckPoint Firewall was not receiving OSPF adjacency from a Cisco IOS 12.3 3640 Router. Apparently Cisco released a new feature in 12.3 (and 12.2T) that is ON by default… even though it is NEW. The feature is called, Link-Local Signalling (LLS). LLS confuses OSPF on the Nokia (even…