[parisc-linux] ARP resolution trouble

[parisc-linux] ARP resolution trouble

[baddy]

Hi,

I've got a B132L+ under 2.4.20-pa23 and I am encountering with ARP 
request/resolution : sometimes my B132 become unreachable from some
machines of my LAN. Every host is concerned and it seems to happen
every times the host is idle on the LAN.

Here is what I saw :

    - the ARP mechanism flush the mac address table of the host (due
    to a timeout because the host was idle). If the host want to reach the
    B132, it has to make an ARP request.

    - this request is not see at all by the B132L which already have the
    mac address of the host in his mac address table (I think it is because
    the B132L keep it from a previous trafic).

    - the host must do a broadcast (a ping broadcast for example) to be
    beeing reachable again from the B132.

    - if I keep a connection open between the host and the B132 (like a
    ssh session for example), this never happen.

Any idea ?

Re: [parisc-linux] ARP resolution trouble

[Alan Cox]

On Sul, 2003-06-22 at 09:17, baddy@free.fr wrote:
>     - this request is not see at all by the B132L which already have the
>     mac address of the host in his mac address table (I think it is because
>     the B132L keep it from a previous trafic).

Sounds like you have a buggy bridge somewhere. Some vendors can't read
the specs and drop rather than flood unknown mac addresses. This breaks
stuff just as you describe.

[parisc-linux] Re: ARP resolution trouble

[Bad Max]

Hello

On 22-juin-03, you wrote:

| > On Sul, 2003-06-22 at 09:17, baddy@free.fr wrote:
| >>    - this request is not see at all by the B132L which already have
| >> the
| >>    mac address of the host in his mac address table (I think it is
| >> because
| >>    the B132L keep it from a previous trafic).
| > 
| > Sounds like you have a buggy bridge somewhere. Some vendors can't read
| > the specs and drop rather than flood unknown mac addresses. This breaks
| > stuff just as you describe.
| > 

Thanks Alan it was effectively my Cabletron switch the faulty device. I
plugged
every host on a 3Com switch and everythink look good.

The most strange is that this switch was working perfectly for one year and
the
B132L was the only host affected by the bug (I never encountered this bug
with
the other host).
-------
Bad Max
========
Amiga User
GNU User
WWW: perso.club-internet.fr/badmax

Re: [parisc-linux] Re: ARP resolution trouble

[Alan Cox]

On Maw, 2003-06-24 at 21:15, Bad Max wrote:
> The most strange is that this switch was working perfectly for one year and
> the
> B132L was the only host affected by the bug (I never encountered this bug
> with
> the other host).

Most boxes have regular traffic - samba broadcasts, snmp probes, ipx
rip/sap whatever. 

[parisc-linux] Re: ARP resolution trouble

[Bad Max]

Hello

On 24-juin-03, you wrote:

| > On Maw, 2003-06-24 at 21:15, Bad Max wrote:
| >> The most strange is that this switch was working perfectly for one year
| >> and the
| >> B132L was the only host affected by the bug (I never encountered this
| >> bug with
| >> the other host).
| > 
| > Most boxes have regular traffic - samba broadcasts, snmp probes, ipx
| > rip/sap whatever. 
| > 

The B132L is a PDC/DNS/DHCP/Router on my network. The other host are
mostly clients, no ipx, no snmp. DHCP requests were accepted and the
B132L was reachable until ARP timeout. 

The only thing I don't understand is why the B132L was the only host
affected by the trouble.
-------
Bad Max
========
Amiga User
GNU User
WWW: perso.club-internet.fr/badmax