Posted on in Networking
The last thing I want to do when some network administrator leaves my organization is change all the login passwords on the Cisco network devices. (For now, let's just assume the administrator in question didn't know the enable secret.) If you have relatively few machines, it's easy to setup username …
Posted on in Networking
If you followed my recent Cisco Catalyst rate-limiting post, you already know that policing traffic on a Cisco Catalyst switch requires a bit of thought. Mainly, you have to do a bit of calculating to determine the best bucket size for your application. The good news is that achieving the …
Posted on in networking
This is the full text rate limiting example that accompanies my Catalyst rate limiting post. This example was derived on a Cisco Catalyst 2960 and should be ready to copy and paste directly to your device.
mls qos
ip access-list extended ACL_SLAP
permit ip any any
class-map match-all CLASS_SLAP
match …Posted on in networking
If you need to limit the inbound bandwidth of a switch port on a Cisco Catalyst, the key is in the QoS configuration. Rather than going into an depth discussion of QoS and how it works, let's skip that (check out Wikipedia to get started with that) and jump into …
Posted on in networking
Ever so often, you need to check the status of a the power supplies in
Posted on in Networking
If you work on a fairly spread out network (or have remote clients), you might be managing Cisco Catalyst switches that are far, far away. For a long time, I thought the only option was to have someone on site to pre-configure the switch just enough to get it on …
Posted on in Networking
Sending log messages from your Cisco network equipment to a centralized syslog server is a fairly normal activity. Most of the time, this setup works fine and there's no reason to do anything out of the ordinary. Occasionally though, you might need to run a debugging session over an extended …
Posted on in Software
If you've spent any time managing a web site, you are undoubtedly familiar with the dreaded Alexa rankings. It's common knowledge that these numbers are fairly useless since they depend on the end user having the Alexa toolbar installed. Obviously, not everyone has this. To make matters worse, Alexa only …
Posted on in Networking
Anyone who has ever done anything remotely "interesting" with a run-of-the-mill broadband router is undoubtedly familiar with the concept of port forwarding. In the case of some applications (<acronym title="Peer-to-Peer">P2P</acronym> comes immediately to mind, but the <acronym title="Real-time Transport Protocol">RTP</acronym> part of <acronym title …
Posted on in System Administration
I recently installed Microsoft Windows XP Pro in Parallels Desktop on my iMac. After going through the usual motions of updates and tweaks, I set up my user account so that I wouldn't be using the built-in Administrator account. After rebooting the virtual machine, I noticed that on restart, I …
Posted on in Graphics Design
Until recently, I used websites to convert PNGs or JPEGs into ICOs for me. My method was pretty simple: Google for "convert PNG to ICO" and use the first site that came up.
I've recently decided that this method is bogus. Creating a 16x16 favicon.ico is incredibly simple, as …
Posted on in System Administration
When working in an office environment, it's very easy to gather multiple administrators into one office and show them how a task is done. If, on the other hand, your administrators are spread out, these impromptu meetings are nearly impossible. GNU Screen (in multiuser mode) can solve all your problems …
Posted on in Software
I wrote recently about using Subversion over SSH. A minor annoyance with that setup is the need to enter your system password at least once, and sometimes multiple times depending on the action you are taking. There are also times when a remote system needs to access another system via …
Posted on in software
If you've ever needed to set up a Subversion repository, you know how long it can take to get WebDAV working with Apache before you even get to the repository set up. Although WebDAV is the best overall protocol for Subversion repositories (it doesn't require real users on the system …
Posted on in Networking
If you've spent any amount of time in Cisco networking with Catalyst switches, you've probably run across a port that is in err-disabled state. The most likely place to find this is in the output of show interfaces status. A switch port can end be error disabled if the software …
