[ILUG] lynksys switches & network problem

[Kevin Gannon]

>Again. It's not so linux topic but I'm not sure this is offtopic. Maybe
>you can answer. Yesterday morning there was a power cut in the office
>building and the switches went down in the rack. After we got power again
>the network went down at several end-points. The strange that they some
>other machine in the network but don't see the gateway (which is the mail
>and one of the file-servers too). As this is weekend I'm not sure who has
>network and who hasn't. We've got Linksys switches and they worked fine
>until yesterday. I think that the problem lies at the switches because the
>ping responses say that destination host unreachable.

Try the following steps to try and rule out things:

1.Find two machine attached to the same switch and ping from host to host.
    If this doesnt work then it is likely the switch is at fault. If it 
seems to be
    the switch make sure that the duplex/speed on the network cards and the
    switch match. Do NOT rely on auto negoiation.

2. If pinging between hosts on the same switch works then try pining from one
     of these hosts to another pc attached to another switch. If this 
doesnt work then
     try finding two hosts attached to the second switch and ping between them.
     If this works then it is the link between the switches at fault.

3. The destination unreachable message is from your router/gateway saying it
     doesnt know how to find the destination you are pinging. So you will 
have to
     look at the router/gateway. Without knowing what kind of 
router/gatewat it is
     I cant help much on that front.

>It seems to me
>that's a problem with ARP tables. Maybe the linux can't change its table
>when the hosts come up ? But I don't think it. Let's see the facts:
>- the switches are unmanagable Linksys EtherFast 10/100 Dual-Speed
>switches (DSSX24, 24 ports)
>- the network cards in the gateway: two Intel EtherExpressPro 10/100 cards
>- the network cards in the client machines: misc

ARP Table problems can occur for loads of reasons and to rule it out rebooting
the PC's and clearing the ARP tables on the router should solve the problem.
However it is unlikely its an ARP problem unless you changed the interface
on the router/gateway for a new box/card.

Regards,
Kevin

>So, what do you think ? I should repair the network until tommorrow
>morning, so every little answer or thought would help.
>Thanks,
>Ago
>
>
>--
>Irish Linux Users' Group: ilug at linux.ie
>http://www.linux.ie/mailman/listinfo/ilug for (un)subscription information.
>List maintainer: listmaster at linux.ie