Networking

If you are frustrated to get your Domain account locked while you are logged on a VPN with different credentials than your Domain credentials, then this is for you. Edit the file %userprofile%\AppData\Roaming\Microsoft\Network\Connections\Pbk\rasphone.pbk with your favorite text editor. All the VPN connections managed by Windows are defined in that file. Search the string UseRasCredentials=1 and replace it with UseRasCredentials=0 for each VPN connection that gets you locked out (or just replace all of them if you are lazy)....

I have been getting increasing number of errors in my Exim log related to GnuTLS Diffie-Hellman prime number. That prime number being too small causes Exim to abort the connection and initiate a new one to send the email over an unencrypted session. The exact error message is: TLS error on connection to foobar.example.com [x.x.x.x] (gnutls_handshake): The Diffie-Hellman prime sent by the server is not acceptable (not long enough). With a recent enough Exim installation, you can define the tls_dh_min_bits parameter to a value that you find acceptable....

If you want to boot with DHCP/PXE/TFTP method and your DHCP is handled by a Mikrotik router and your TFTP server is on another server, then you need to set the next-server and boot-file-name parameters in the network definition. Do not try to set DHCP options (codes 66 and 67) and assign them to the network definition, it will not work. The same applies to the NTP servers option. So, do not do this:...

I had to configure a bunch of ESXi 5.1 servers with LSI 9240-4i hardware RAID controllers the other day. This RAID controller is perfectly supported in ESXi 5.1 but it lacks the monitoring features. To have these, you need to install first the LSI SMIS package on your ESXi hosts. With this, the ESXi server acts as a proxy to query the RAID controller from the network. Then you need a Windows computer running LSI MegaRaid Storage Manager (MSM) software....

This weekend, I finally had time to install a few network cameras from Ubiquiti in my house. The goal was to replace the previous system, which was composed of cheap USB webcams and the software motion , that has been running for years. HP Proliant N40L I had a spare N40L lying around that I used as a storage server for my VMware lab, so I repurposed it to be my future one and only home server running file sharing, monitoring, etc and AirVision of course....

It has been explained many times over the internet, so I won’t cover that. One thing you have to pay attention to is, if you run snmptt as a daemon, be sure that it has the right to write to Nagios FIFO. On my Debian system, I had to run snmptt as nagios user. Then, when you convert the MIBs to snmptt.conf file format, sometimes it will fail because the MIB is not RFC compliant....

So, like me, you want to have redundancy for your virtual machine network. For my lab setup, I use a refurbished Cisco router 3825 with two gigabit interfaces, two Procurve 2810-24G and a small server with 4 gigabit interfaces for the ESXi. You just have to: team the NICs on the ESXi (use src-mac + beacon probing), use port-channel on the Cisco router and src-mac too, configure the switches exactly the same way as if there wasn’t any redundancy, add a link between the two switches and configure it to transmit the VLANs you need, don’t forget to add STP on the switches and put a high priority (low number) on the link between the switches....