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Archive for June, 2010

Originating IP address

June 15, 2010 1 comment

More work securing the network. I was setting up RADIUS authentication and authorization using the Network Policy Server role of Windows 2008 R2 (that will be another post). Here is a simplified network diagram.

Everything worked perfectly for the local router (rtr01) and switch (sw01) so it was time to do the same on the remote devices. I started with the switch (sw02) and then moved onto the router (rtr02) when I ran into problems. I couldn’t log into the router. I tried the router’s local username which did work indicating the router couldn’t authenticate against the RADIUS server. This seemed very odd to me since the switch, which is further away, worked perfectly. I tried a simple ping to the server and it failed. Now I was really confused, because the switch could ping the server but the router couldn’t.

At this point I’m thinking it’s some strange configuration setting on the router so I fire up Google and start searching. I come across the Cisco Extended Ping and Traceroute commands as well as a short statement indicating the originating address is the IP of the interface the packet leaves. So I try an Extended Traceroute using an originating address of 199.254.8.189 and it works. This means that a reverse route from the server to the 172.16.19.52/30 subnet doesn’t exist. Adding the following route to sw01 fixed the problem:

ip route 172.16.19.52 255.255.255.252 199.254.7.253

Switch sw01 already had a route to the 199.254.8.128/25 network. Until now there was never a need to know how to get to the WAN interfaces of the routers.

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Categories: Networking Tags: ,

Magic Eraser

June 4, 2010 1 comment

So there was a stain on the kitchen counter and nothing seemed to work.  The light bulb above my head lit up and I reached for the trusty Magic Eraser.  After just a few strokes the stain was gone and all was right again in the world, or so I thought.  The next day my wife and I noticed some strange streaks on the counter.  It turns out that using a Magic Eraser on a laminate counter will make the area dull.  No I have not upgraded to solid surface counters yet, but this will increase the priority for doing that.  After some research I tried putting olive oil on the counter and rubbing it in with a paper towel.  It helped a little bit, and maybe a few more applications will help more, but the bottom line is be very careful when using your trusty Magic Eraser on your laminate counters.

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