View Full Version : interface mixup ?
Marlow
10-17-2005, 09:41 AM
How comes, that the order of the interfaces can be different in ospf in comparison to what star-os tells you ?
The particular example where i've seen it is with 2 pcmcia cards:
interface wlan1 is wpcm1, interface wlan2 is wpcm0.
Version of Star-OS: 2.10.0
How comes ?
/Marlow
bairdc
10-17-2005, 10:21 AM
This can be confusing. Lonnie or Tony can correct me, because I'm really just guessing at the reason for this, but when StarOS was originally developed, I think it was intended that you would never see the actual underlying Linux interface names. My guess is that it was assumed that WLANx would be easier to identify as a wireless card that WPCMx. Also, the interface numbers were adjusted so as to start at 1 instead of 0, as they do in Linux. Anyway, this Linux interface "hiding" was sort of defeated when Zebra/Quagga was added, as well as iptables support. So, as a result, when using Quagga or iptables, you have to remember that the interface names do not match up with what StarOS calls them. I'm sure this will probably be remedied in v3.
Now as for your specific case, I'm not sure why you're getting wpcm0 as wlan2 and wpcm1 as wlan1. I've never see that. Mine have always been wpcm0 -> wlan1, and wpcm1 -> wlan2.
Craig
bradg
10-17-2005, 10:28 AM
As far as I know, all of the physical interfaces are "off by one" in Zebra/Quagga.
For example, ether1 in Star-OS is eth0 in Zebra/Quagga, wpci1 in Star-OS is wpci0 in Zebra/Quagga, and so on.
All I can think of is that it could be to avoid a perception/confusion issue stems from the fact that (non-*NIX or Cisco) people get confused when you refer to an interface as number "0".
I've never seen the interfaces reversed in numbering, though. Are you sure about that?
Brad
How comes, that the order of the interfaces can be different in ospf in comparison to what star-os tells you ?
The particular example where i've seen it is with 2 pcmcia cards:
interface wlan1 is wpcm1, interface wlan2 is wpcm0.
Version of Star-OS: 2.10.0
How comes ?
/Marlow
The device ordering for PCMCIA cards is done by slot, and not the underlying physical device name. For example, pcmcia slot #1 will be wpcm1, etc. If there is a card insertion order difference, then the underlying physical device ordering may vary until the next reboot.
Marlow
10-17-2005, 01:06 PM
Well .. that means that you better not configure things like iptables and ospf before you are sure what interface is what and that all interfaces are connected. On replacing interfaces that gives major problems, will at least require downtime for the whole box.
/Marlow
With a router, you must treat pcmcia devices like any other ethernet card. If you add, or remove it during operation, or add it after your system is setup, you may experience an interface reordering issue.