Networking

An amazing group of people gathered at this years Chaos Communication Congress to set up multiple alien wavelengths for 34C3. If you are interested in the detailed setup be sure to check out the slides.

If you couldn’t make it to this years DENOG9 conference you can find @marcnetismus and my slides on ‘200G over alien wavelength’ here. If you have any questions feel free to ask.

If you couldn’t make it to this years DENOG8 conference you can find my slides on ’nesting dwdm within cwdm’ here. If you have any questions feel free to ask.

We recently bought a Cisco SG500 at work as we needed a cheap switch with 4x SFP Interfaces. In the default configuration the SG500 only offers 2 SFP Ports for networking, the other 2 are used for stacking and they don’t show up in show interface status. Howsoever if you try to configure gi28 no error is thrown. Confusing as hell. But as mentioned before I needed 4x SFP for networking so I went on a google hunt and found nothing. The manual at least suggested that it’s possible but I couldn’t find out how. ...

If an error like this shows up in your logfiles: ix0: <Intel(R) PRO/10GbE PCI-Express Network Driver, Version - 2.5.15> ix0: Unsupported SFP+ Module I might be able to help. It’s not as straight forward as with linux, but we’ll make it work. First off we need to modify the sourcecode of /usr/src/sys/dev/ixgbe/ixgbe.c as follows: static int allow_unsupported_sfp = TRUE; And then we need to recompile the kernel module: cd /usr/src/sys/modules/ixgbe && make install and then reboot our system. If everything goes well the interface will show up somewhat like this when executing ifconfig: ...

I recently got myself a Intel X520-DA2 10GBE NIC and some SFP-10G-SR+-SO SFP+ Modules to toy around with. After assembling the PCIe card I was luckily surprised that my kernel brought up the NIC without any difficultys, so I plugged my SFP+ modules into the server, only to be greeted with: ixgbe 0000:24:00.1: failed to load because an unsupported SFP+ module type was detected. ixgbe 0000:24:00.1: Reload the driver after installing a supported module. Yay. After 2 hours of useless googleing I asked a friend who happens to be a linux kernel maintainer, and luckily he knew just the fix therefore: ...