Special-use IPv4 addresses and domains

Posted on 2010-01-18 by Oliver Gorwits

You’ve probably heard of RFC1918 – the well-known set of networks assigned for use in off-Internet, private networks. In fact there’s a much more useful RFC, one which lists not only these but a group of other networks and subnets … Continue reading →

Posted in Best Practices, Documentation | Comments Off on Special-use IPv4 addresses and domains

Cisco firewall SMTP “fixup” considered harmful

Posted on 2009-11-26 by Oliver Gorwits

This issue is old and familiar to us, and crops up about once every six months or so. I thought it might help to document the situation more publicly. On Cisco firewalls (PIX or the newer ASA), various protocol inspection … Continue reading →

Posted in Cisco Networks, Firewall, Mail Relay, Message Submission | 9 Comments

Fixing the iPhone OS WiFi auto-login problem

Posted on 2009-10-12 by Oliver Gorwits

Some time ago, shortly after iPhone OS 3.0 was released, we received a number of reports from users that our VPN-based wireless service had become unusable. For those not familiar with this service, OWL is one of our local wireless … Continue reading →

Posted in VPN, Wireless | 4 Comments

Connecting to JANET

Posted on 2009-10-06 by Oliver Gorwits

Sorry it’s been a little while since our last post. We’re just coming to the end of the summer vacation, the point when we (and most other IT support staff around the university) get things ship-shape in time for the … Continue reading →

Posted in Backbone Network, Cisco Networks | Comments Off on Connecting to JANET

Moving to a new ARP and MAC logging system

Posted on 2009-09-08 by Oliver Gorwits

To locate a node (workstation, printer, etc) on the network, you use a combination of the ARP logs from a router, and the MAC-port mappings from a switch. The ARP log translates IP to MAC, and the MAC-port log translates … Continue reading →

Posted in Backbone Network | Comments Off on Moving to a new ARP and MAC logging system

Hello world!

Posted on 2009-08-21 by Oliver Gorwits

Welcome to the OUCS Networks Team blog. This blog is a new venture for us, but it’s something we’ve wanted to do for a long time. Our days are filled with a mix of the usual IT firefighting but also … Continue reading →

Posted in Uncategorized | Comments Off on Hello world!