Recent posts (paged)
IPv6 Only Test
The IPv6 designers refused to define an IPv4/IPv6 gateway, because it's a contradiction to the NO-NAT, End2End paradigm of IPv6. The result is that IPv6 doesn't really lift off, because every IPv6 user has IPv4 too (Dual Stack), which gives no pressure to move on to implement IPv6. Large providers had to implement N...
ejabberd on debian with pam
Problem: After updating from debian lenny (5) to squeeze (6) ejabberd authentication (PAM) stopped working. Solution: ejabberd uses an external programm called epam to authenticate. But this programm had no permission to use pam. I had to type these commands: chown root.ejabberd /usr/lib/ejabberd/priv/bin/epam chmod...
Mysql "Select" Output Turned Arround
When you have a mysql table with lot's of attributes, it's hard to read the output of a statement like this in mysql: select * from table limit 1; The data is folded very ugly. Easy Solution: select * from table limit 1 \G Mysql is showing one "Fieldname: Value" per line.
Update Cisco Catalyst Software
I had to update the software of a new Cisco Catalyst 4948 yesterday. As usual I did: copy tftp://<hostname>/<filename> bootflash: conf t boot system flash bootflash:<filename> exit reload But the switch ignored the new software image. During boot it said: Booting first image from bootflash Solution: The config-regis...
Cisco Routing - Administrative Distance
Cisco routers are capable of different routing protocols and static and connected routes. Every routing protocol engine has its own distance/metric/weight to decide which route is best. When a routing protocol has chosen its best route, the route is entered into the routing table. The routing engine uses an "adminis...
Pirelli Modem does allways NAT
When I restart my Pirelli modem it allways disconnects all TCP connections! After the connection table of the Pirelli is flushed (by rebooting) it sends a RST for the next packet of any TCP connection.Why doesn't it simply forward this packet. Client and servers don't care if a router on the way is rebooting. Pirell...
Pirelli doesn't forward port 7070 correctly
Problem: Pirelli modem is not transparently routing traffic for tcp port 7070 and 554. I'm using a Pirelly VDSL modem at home in pure routing mode (no NAT, no QoS). When starting a TCP connection to port 7070 (or 554), the Pirelli modem answers the TCP SYN with SYNACK, then it tries to connect the original server wi...
Howto: Merge two PDF Files onto One Page
Problem: If you want to add water marks onto a pdf document, you have to merge two pdf files into one pdf file. Solution: On Linux there is a tool called pdftk (PDF Toolkit), which can do this. pdftk <letter.pdf> background <background.pdf> output <letter-with-background.pdf>
cdrecord is called wodim now
I don't burn CDs often, but when I do I still look for "cdrecord", which doesn't exist on debian anymore. Debian forked the source and renamed it to wodim , because of a license dispute between the Debian maintainers and cdrtools author Jörg Schilling.
WScale and Cisco Content Switch CSS.
Problem: Windows 7 clients wait 5 seconds to send simple HTTP requests to a web server behind a cisco CSS content switch. But there is no delay when the client connects directly to a web server behind the CSS. Description: I found one difference between CSS and non-CSS connects: the TCP WSCALE option. When the CSS i...