Appendix E - Laptop-Specific Issues
Preparing the PC
When selecting a laptop to use, be aware that traffic passes through the system bus differently than in a desktop, due to the nature of the pcmcia NICs. Attempts to use IBM Thinkpad 755Cs (486DX systems) resulted in failure as the PCI-to-PCMCIA bridge caused problems in this model. Moving to a Pentium-class laptop resolved this. I have tested LRP on a few different models with the following results:
|IBM ThinkPad 755C||Required the floppy=thinkpad parameter in the syslinux.cfg file. Failed due to the PCI-PCMCIA bridge problem.|
|IBM ThinkPad 760E||Did not require the floppy=thinkpad parameter. Works, but the MAC address of the NIC must be assigned manually.|
|IBM ThinkPad 760EL||Did not require the floppy=thinkpad parameter. Works, but the MAC address of the NIC must be assigned manually.|
|Compaq Armada 1540||Failed; suspect a memory problem with the laptop.|
|Canon Innovabook 490CDS||Works. Did not require any special modifications.|
It is also not a bad idea to remove the hard disk if you are not using it. Just like when using a desktop, everything that is not being used should be removed to reduce heat.
This is simpler in a laptop than in a desktop. The pcmcia drivers will handle assigning port addresses and irqs for you. The problem is that you will not know which NIC is eth0 or eth1 until after the system is up and running. When the system is completely configured, test it out. If you can't access internal services from the outside, try swapping the patch cables. Once traffic is passing properly, then mark each NIC as "eth0" and "eth1".
The pcmcia-aware modules.lrp file recognizes only 3com 3c589, Xircom IIPS, and NE2000-compatible NICs. I use Kingston KNE-PC2T NICs (which are no longer in production) without any trouble, however any NE2000-compatible NIC should work.
Preparing the Disk
There are a few differences when doing this with a laptop. First, the old modules.lrp file must be discarded, and the modules.lrp with the pcmcia modules included must be copied to the disk. Depending upon which laptop you select, you may require the floppy=thinkpad parameter in the syslinux.cfg file (see above).
In some cases, the NIC's MAC address may not be readable by the pcmcia modules. In this case, you will need to assign the MAC address explicitly. When the system boots, watch the messages that appear on the screen (or press [Shift]-[PgUp] to scroll back up through the messages) to see what MAC address has been assigned to the NICs. If the MAC addresses listed do not match the MAC addresses on the NICs, you will need to explicitly assign the MAC addresses. I have chosen to do this in the /etc/init.d/network file (see Troubleshooting, Problem #7). After the explicit assignment of the MAC address, you can verify that it worked by typing
ip addr [Enter]
at the command prompt, and reviewing the results on the screen. This will display all of the interfaces on your laptop, and give you their MAC address, IP address, and state of the interface (UP or DN).