Skip to content

Aaron's Worthless Words

It's possible that someone somewhere needs to know this.

2008-04-07

QoS Policing

We covered QoS tagging the other day, but that just marks packets. I think you’re old enough now that we should actually do some policing. Policing is where you restrict the amount of bandwidth that a flow or set of flows can use. For example, say you have a site that serves webpages to the […]

2008-04-05

Qos Tagging

I’ve been trying to get some experience on Cisco VOIP, and, as you probably know, Quality of Service (QoS) is quite important in that realm. Since VOIP is very time-sensitive, you have to be sure your gear delivers the voice packets first. A packet in an HTTP transaction can wait another 200ms without any problems. […]

2008-04-04

ASA + HSRP/VRRP/GLBP = undef

I use Google Analytics to track the 2 or 3 hits I get a day, and sometimes I see some interesting search terms. Yesterday, some googled up the term “does the ASA 5505 run HSRP”; I think that deserves a short article. The ASA and PIX firewalls don’t actually run any of the usual HA […]

2008-04-02

DHCP on the ASA 5505

Let’s keep going with our example setup on the ASA 5505 and set up DHCP on this guy. You can set it up to either forward (relay) DHCP requests to a DHCP server somewhere or have it be the DHCP server. Let’s do it. To set up DHCP forwarding, you have to configure where the […]

2008-04-01

Setting Up VLANs on an ASA 5505

I’ve had my ASA 5505 in place at home on my Comcast cable for a few weeks now, and, let me tell you, this thing rocks. I did, however, have a few problems finding a clear answer on how I could set up my VLANs. It turns out that the base license on the ASA […]

2008-03-22

Default Route via DHCP on an ASA 5505

I finally got my ASA 5505 up and running at the house, but I ran into a little problem — the box wouldn’t add the DHCP-provided default route into its routing table.  That one threw me for a loop since the box is made for SOHOs, but it makes sense in some corporate, lazy way. […]

2008-03-21

Configuring GLBP

Believe it or not, I got a request for an article on how to configure GLBP. I’m as shocked as you are, so here it goes. The Gateway Load Balancing Protocol (GLBP) is another Cisco-proprietary protocol for providing highly-available gateways on a network…but there’s a twist. GLBP, as you can figure out from the name, […]

2008-03-21

Trunking on a Catalyst Switch

If you didn’t now already, trunks are connections between switches that carry traffic for all VLANs. It allows you to have, say, VLAN 10 and VLAN 20 on two switches appear as the same network. Unless you’re a really small shop, you’ve already dealt with trunks, so there’s no need for an introduction. Let’s say […]

2008-03-18

HSRP vs. GLBP

HSRP (Hot Standby Router Protocol) is a Cisco-proprietary method for supplying a highly-available gateway for hosts to use. GLBP (Gateway Load Balancing Protocol) does the same thing. So, what’s the difference? HSRP works on layer 3 and provides a standby IP address for hosts on that network to use as their gateway (or other routers […]

2008-03-18

GRE Tunnels and Encryption

GRE tunnels rock.  They are interfaces on a router that are used to “connect” to another router somewhere on your LAN, your WAN, the Internet, wherever.  The most popular use for them is for router-to-router VPNs. I’ll let my friend Josh from blindhog.net show you how to do it.  He’s got a video on how […]