For some reasons it may be useful to connect via serial cable instead of using a real infrared link. Bjorn Hanson wrote: "Using a cable, I managed to get a PPP connection through my Ericsson SH888. I did the following (maybe some steps are wrong but they worked for me :-)
added alias tty-ldisc-11 irtty to /etc/conf.modules
edited /etc/irda/drivers to irattach /dev/ttyS0
manually inserted the irda and irtty modules using modprobe
run kppp using /dev/ircomm0 (through symlink /dev/modem)
executed stty < /dev/ircomm0
ping the host
ifconfig irda0 down
Everything worked fine for ping and ssh (doing ls -l a couple of times) but the computer hang when I tried to mail (Netscape) this through that PPP. After reboot I tried both Netscape and lynx. Both were able to establish contact but none got any data."
Another way by Claudiu Costin:
Linux 2.2.5 with IrDA compiled as modules
Because irattach don't make kernel to load automatically IrDA stack, let's type modprobe actisys .
Now, irattach /dev/ttyS1 -d actisys where COM2 is used for null link
ping <address> works very good!
This has to be done for both machines.
Please note this is not the recommended way to connect two machines. Use PPP instead. Though I cannot see how this approach is useful I have included it beause it was asked sometimes in the mailing list.