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Posts in Networking
Cleaning up eth[0-9]_rename files on Fedora core hosts
I kickstart'ed a Fedora Core 10 host last week, and decided to add a second NIC to the host to do some network bonding testing. Once the I added the NIC and rebooted the host, I noticed that one of the interfaces had the "_rename" extension: Network interface names are assigned by udev at boot time, and after a bit of poking around in /etc/udev I came across the following udev rule file: It appears that the the same mac address got assigned to both eth0 and eth1, which was causing one of the devices to get renamed during system initialization. To fix this issue, I updated the MAC address that was associated with eth0 rule, which allowed everything to come up cleanly. Udev is pretty sweet, and I will have to add it to my list of things to blog about it in the future.
$ read more →Berkeley Packet Filter support in OpenSolaris
While catching up with e-mail this morning, I noticed that the OpenSolaris community is planning to integrate the Berkeley packet filter into opensolaris: "This case seeks to build on the Crossbow (PSARC/2006/357[7]) infrastructure and provide a new (to OpenSolaris) mechanism for capturing packets: the use of the Berkeley Packet Filter (BPF). The goal of this project is to provide a method to capture packets that has higher performance than what we have to offer today on Solaris (DLPI based schemes.) It also has the added benefit of increasing our compatibility with other software that has been built to use BPF." This is awesome news, and each month it seems there are fewer and fewer packages I have to bolt on to my OpenSolaris installations. Nice!
$ read more →Locating firewalled hosts with arping
One of my friends pinged me last week and asked me how I would go about locating all hosts on a layer-2 network. Typically I would use fping with the "-g' option, but he wanted to find all hosts including ones that were running host-based firewalls. For this specific case, I would use the Linux arping utility. This nifty utility allows you to locate hosts using ARP requests and responses, which hosts running host-based firewalls would still respond to: In the sample session above, I was able to locate a host that was running iptables with a drop all incoming traffic policy…
$ read more →Renaming network interfaces on OpenSolaris hosts
While preparing my presentation for the Atlanta UNIX users group this past weekend, I accidentally created a VNIC with the wrong name. Instead of removing it and recreating it, I decided to test out the "rename-link" subcommand that was introduced as part of project Clearview. The rename feature worked swimmingly, and with a single dladm command I was able to rename the vnic6 interface to vnic5: I am super impressed with the work that the Sun networking team has done to simplify network interface management!
$ read more →OpenSolaris network virtualization slides
I gave a talk tonight on network virtualization at the Atlanta UNIX users group. The talk focused on the OpenSolaris network virtualization project (project Crossbow), and described Crossbow and how to use it. I posted the slide deck I used on my website, so you can grab the presentation and the latest Nevada build and start creating virtual networks today!
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