Recent posts (paged)
Cisco IP Phone and NTP
Problem: A Cisco IP phone (in my case 7970G) does not sync with an NTP server. The phone sends an NTP request, receives an NTP response, but does not set its date and time. Solution: It's a known bug of Cisco's IP phone software releases 8.3(3) or higher according to Cisco bug id: CSCso40588. Cisco says that these p...
Multiple Routing Tables with IPTables
Challenge: You have a linux based firewall, which should forward all internal and external traffic of its connected clients through a VPN tunnel, and at the same time the traffic from the firewall itself should not go through the tunnel (e.g. the tunnel connection packets). Solution: There are lots of howtos for thi...
One Mouse and Keyboard for Two Computers
I just read that MircoSoft announced a "new" software to control two WindowsPCs with one keyboard and mouse. It might be new to MircoSoft but a software for this exists since about 1998. When I had both Linux and Windows on my desktop some years ago I used x2vnc for this. Read on: http://fredrik.hubbe.net/x2vnc.html
Squeezebox Remote Streaming
I use Logitech Squeezeboxes at home for my music library, Internet radio, and podcasts. The server is running on my Linux server, and the clients are Squeezebox Boom and Squeezebox Duet. If you like to stream to your desktop PC, you can use several software squeezebox clients, but there is also a simple way to strea...
Windows Network Load Balancing NLB and Cisco Routers/Switches
Problem: Windows NLB IPs are are not reachable through and from Cisco routers and switches. NLB services could be IIS arrays, Exchange CAS arrays, etc. Solution: NLB mode was set to Multicast. In this mode Windows incorrectly uses multicast mac addresses. Set the NLB mode to Unicast and configure static mac address ...
Cisco has weird naming conventions for groups of interfaces
If you want to bind some ethernet interfaces into one logical interface between two ciscos switches you have to configure an interface first: interface Port-channel 1 then add some interfaces into this new interface: interface GigabitEthernet 1/0/1 channel-group 1 mode active and you can check the status with: show ...
BGP Looking Glass
If you like to search through the full Internet routing table from around the world, you can find some looking glasses at http://www.traceroute.org/ or http://www.routeviews.org/ . e.g. Routeviews has telnet access to zebra servers (route-views.isc.routeviews.org,...)
L2TP tunnel between two cisco routers
Problem: a Cisco 1941 [15.1(2)T2] (Client) tries to connect to an Cisco7300 [12.3(22)] (Server) using L2TP, but after successful authentication of the client the server drops the connection. Solution: The client tried to authenticate the server, but the server had no password for authentication. Normally only the cl...
Using an HP scanner on the command line
I don't use Gnome, KDE, etc. My window manager is WMX with some patches. Without all those fancy window environments, you get rid of all magic auto configurations, and wizards at the same time, and you can configure your system like real man do: using the command line. ;-) I bought a HP OfficeJet Pro 8500 A910 last ...
Restore data from a single disk of an HP/Compaq SmartArray raid1
If you look into a harddisk from an HP server with smart array configured for raid1, you will recognize that the partition table of this disk has only one partition: Device Boot Start End Blocks Id System <device>p3 1 1 8001 12 Compaq diagnostics The real partitions are invisible? No. I found the start of the real d...