I would like to use ICQ with Linux. I use SuSE Linux 7.1 with kernel 2.4.0 (I read that there is something facilitating the connection to ICQ with 2.2.x, but I have to use kernel 2.4.x in order to be able to use my USB ISDN adapter).

I don't have a network, I would just like to be able to use ICQ (with kicq, licq or any other Linux clone) from Linux on the machine that is connected with the Internet. Web access, ftp and other services work well, but I can't connect to ICQ, at all. Network messages of licq:

19:46:26: [UDP] Requesting logon (#31072)...
19:46:26: [UDP] Resolving icq1.mirabilis.com
19:46:26: [UDP] ICQ server found at 205.188.153.98:4000.
19:46:26: [UDP] Creating local server.
19:46:26 [UDP] Opening socket to server.
19:46:36: [WRN] Timed out after 10 seconds (#31072), retry 1 of 6...
19:46:46 [WRN] Timed out after 10 seconds (#31072), retry 2 of 6

... and so on. I suppose this is due to the firewall functionalities of the kernel (I didn't install an additional firewall, security is not a very important issue for me because I use a dialup account with dynamic IP addresses and am usually only connected to the Internet for a relatively short time). Unfortunately, I am not very experienced with Linux and firewalls. I tried out different things, but I didn't succeed, and I don't even know which of these attempts are worth pursuing furter.

A) IPTABLES

I have read that iptables can be used to configure the netfilter for 2.4.X kernels. I tried out iptables and set up very permissive rules that should let through everything, but even then I couldn't connect to ICQ. Might I have to open ports in addition to setting up iptables rules and how is this done?

Furthermore, I notices that I cannot use iptables any more. In order to use it, I had to load the module ip_tables.o (e.g. with modprobe -v ip_tables). This used to work, but now, I receive the message "Device or resource busy". ip_tables.o can't be loaded, and I cannot use iptables.

B) SOCKS PROXY

I read that a socks proxy might help. One that was frequently mentioned was Dante. However, I read that it only supports socks4 and that it can't work with the older ICQ protocol relying on UDP (and the Linux clones use the older ICQ protocoll; that seems to be why a logon attempt to login.icq.com:5190 results in a bad version error).

I decided to use socks5 (from socks.nec.com), which supports socks5 (I used the RPM socks5-1.0r10-5.i386.rpm). It seems to work to a certain extent, but in the end there was an authorisation failure). My configuration:

/etc/socks5.conf:
auth 127.0.0.1 - u
permit u - 127.0.0.1 - - -

I put a username (aes5) and a password in /etc/socks5.passwd

I start socks5 with the command
socks5 -d -s -b 0.0.0.0:3000

The messages are:

01787: Socks5 starting at Sat Nov 17 20:22:18 2001 in normal mode
01787: Config: Reading config file: /etc/socks5.conf
01787: Interface Query: if0 addr/mask is 0100007f:000000ff
01787: Interface Query: if0 is lo(1) with 1 IPs
01787: Config: Config file read
01787: Socks5 attempting to run on interface 0.0.0.0:3000
01787: Accept: Waiting on accept or a signal

Then I start kicq, which supports socks5 without having to be socksified. In preferences I indicate that a socks5 proxy is used with IP address 0.0.0.0 on port 3000 (the same I specified above when starting socks5. I also enter the username and password I entered in /etc/socks5.passwd.
I try to go online in kicq.

socks5 reacts as follows:
01786: Child: Starting
01786: Checking Authentication
01786: Check: Checking host address (000007f == 0100007f)?
01786: Check: Checking port range (0 <= 1371 <= 65535)?
01786: Auth: Line 2: Matched
01786: Socks5: Told client to do authentication method #2
01786: UPWD: Password file is /etc/socks5.passwd
01786: UPWD: successful: user is aes5
01786: Socks5: Read request failed: Bad file descriptor
01786: Socks5: Read request failed: Bad file descriptor
01786: Auth Failed: (127.0.0.1:1371)
01786: Proxy: Done cleaning up
01787: Accept: Waiting on accept or a signal

The messages from kicq are:
Socket created attempting to connect
[SOCKS] Trying to use SOCKS5 proxy
[SOCKS] Socket created attempting to connect
[SOCKS] Authorization failure

It seems that the IP, the port and user name / password are recognised, but that the authorisation fails because of something else I don't know.
I also tried it with a more permissive /etc/socks5.conf (not requiring user name and password), but the result was the same.

Can anyone help me?
The solution doesn't have to be with socks5, of course, I just don't know which paths I should follow. As I wrote, I don't mind about security decreasing slightly, and I don't necessarily need the possibility of file transfers (it would be nice if it worked, but I would be satisfied if I could send messages and see who is online).

Thank you for any advice!