Problems Solved

When I am working on computery things, I often search the web for answers to my problems. The idea of this page is that if I write up some of the solutions I find, then other people will find them. It is just my way of putting a little bit back into the web.

Debian, uw-imapd and reading newsgroups (nntp)

If you want to read newsgroups from more than one location, and keep track of your read articles. This presumes you have the INN2 packages installed and that you already have news flowing.

You have probably tried it but got a message saying Unable to scan newsgroup spool directory

edit /etc/c-client.cf and make it look something like:

I accept the risk
set news-active-file /var/lib/news/active
set news-spool-directory /var/spool/news/articles

And it works

Checking the line length on a BT phone line

This can be useful for checking whether ADSL is likely to work.

You can test your approximate line length by dialling (on your intended ADSL line) "17070", The response will tell you the number of your circuit. Then enter "3", then "1" (you ARE authorised, aren't you?), then "2". If you then hang up, the test system will call you back and tell you the approximate distance distance from your exchange.

Keeping a mixed system in Debian

See http://www.debian.org/News/weekly/2002/1/mail. It is an attachment to a debian weekly news article that explains what to do.

You can then do things like apt-get install mozilla -t unstable which will install the unstable mozilla package.

Stupid locale not support messages in Debian

I got these when I upgraded from potato to woody. When you launch an application from a terminal window you get an 'locale not supported by xlib' message. Also, some applications (mozilla) don't show their window title properly.

Solution: Install localeconf (apt-get install localeconf) and then reconfigure locales (dpkg-reconfigure locales)

Actually, I've now not so sure that this works.

Networks bringing up ISDN lines too often

Lots of people use internet access boxes, ISDN routers or linux boxes running IP masquarading to connect a whole network of computers to the internet. These boxes use Network Address Translation to make the internal workstations think that they have a real internet connection while only using only one real IP address on a standard dialup account.

The problem is that if you are paying the phonebill for your ISDN connection then it can get expensive. Many telecoms providers in the uk have very large minimum call costs.

Often it is found that the ISDN line will come up often for no apparant reason.

This is what I have found you can do to reduce unwanted dialups. This works for networks with microsoft windows clients.

Firstly, firewall (block all access to) port 137 UDP in your router. Windows 95 computers seem to send traffic down this port every 2 minutes. I don't know why. Windows 98 doesn't seem to have the same problem, but I would block the port anyway to be on the safe side.

On each client, go into network properties, TCP/IP (on the LAN interface), DNS settings. Makesure that there is nothing in the domain part of the box. You need to have something in the hostname part, but if you have anything in the domain part then it would appear that the computer tries to do a DNS lookup on itself.

In the same config screen, makesure that there are valid DNS servers set. If your ISDN router includes some sort of DNS proxy then you should just have the (internal) network address of the router set. If not then you should have the DNS servers of your ISP. Incorrect values will cause your machine to keep trying lookups (and thus bringing the line up more).

If you have a Novell server and the workstations have novell client32 installed then remove IP from the list of protocols. This is in Network properties, select Novell client and click properties, select the protocols tab, and remove IP. This assumes that your novell server has IPX installed. If IP is enabled then the computer will attempt to use DNS to lookup the name of your novell server. If you want to use just IP on your novell network then you will have to work out another way of preventing DNS lookups from bringing the line up. Maybe installing a real DNS server on your network which is able to resolve local names will do the trick.

If you do have an ISDN router, and you pay your phonebill then you need to makesure you keep tabs on it. Some ISP's will email you daily logs of your dialup activity. If yours doesn't then consider changing to one that does. A good baseline to consider is the number of calls per day.
If you are buying an ISDN router/nat box then consider what diagnostics it can produce and check that you can block access to certain ports. I would consider installing a Debian Linux system, because then you can include a webcache which can speed up your access and you can also get it to produce very detailed logs. But this leaves you the problem that you need somebody to setup/install it for you.

Where is ImageMagick

I installed ImageMagick (as it happens to write some scripts to automatically put thumbnails of pictures on the web), but I couldn't find the command name to run it.

The solution is that ImageMagick consists of more than one program. display - this will display images. convert will convert and resize images (and lots more) on the command line. There are other commands as well, that you can find in the "see also" section of the display or convert man page.