Blog Host: Howard Plumley, Jr. - Network administrator, Univ. of Florida READ ENTIRE BIO

I would refer everyone to the Sunday (10/02/05) comics "Jeff Macnelly's Shoe" by Chris Cassatt & Gary Brookins. The wizard is IT's hero.

It turns out that networking and plumbing have a lot in common. The more important the connection, the more damage its failure can cause and the harder it is to get to for repair.

First lesson for blogs, Q&As and work: You don't have to have multiple personalities to make it work, just organized. Maybe that is why my PIM (personal information manager) is Time & Chaos.
Posted by Howard Plumley, Jr. Not Teredo
27 SEP 2005 13:36 EDT (17:36, GMT)
When last we spoke I was chasing a problem of blocked access. One IP address worked, but another in same range on same machine would not. Troubleshooting problems can present many avenues, and most are wrong but very enlightening. My mention of the Teredo service as a possible cause was one of those wrong avenues. Teredo is the service to tunnel IPv6 packets over IPv4 links using UDP. There was a problem on some machines when SP2 came out for XP because the service pack blocked the port in question, and when blocked it hung the IPv4 services. That has been resolved. If you are interested in the next generation of the Internet, then anything IPv6 makes good reading. In this case (my problem machine), I was being blocked by a new firewall on campus that detects viruses and locks out that IP address. The block was not under my control or my immediate supervisory level, but instead was the property of a group on campus tasked with stopping P2P and virus storms.
Posted by Howard Plumley, Jr. Welcome to network troubleshooting
26 SEP 2005 00:07 EDT (04:07, GMT)
Hello, my name is Howard Plumley, and I am a network administrator. That is a fancy title for the "go to" guy for our department's computers. I have been working in electronics since 1968 and with computers since 1975. I started on the hardware side and then learned programming. My troubleshooting tends to run physical, mechanical, network and application. Being at a major university (UF in Gainesville) I have had to learn a lot about station wiring and pluses and minuses that go with it. Here the department spends its budget for computers, printers, et al. They own everything up to the wall (usually a RJ-45 jack), which includes the servers in a closet or, if you are lucky, a server room. The "infrastructure" consisting of the cables between jacks, switches, routers, firewalls, DNS and DHCP, belongs to the university as a whole and is managed by a separate department with its own budget (and politics). So I may know how routers work, but I am never allowed to touch one. My firewalls are software on each machine (including servers) because station wiring does NOT give me a choke point for a single appliance. On the other hand, we have top-of-the-line routers, VoIP phones, bandwidth proportioning, really good P2P blocking; all managed by someone else.

I spent Thursday trying to get the people in "infrastructure" to remove a block against a MAC address after I repaired the system. If I give the machine a static address, everything is okay. If I run DHCP (Dynamic Host Configuration Protocol), it is blocked at the building connection to the campus backbone.
Posted by Howard Plumley, Jr.