sslug-teknik team mailing list archive

[Klavs Klavsen <kl@xxxxxxx>]

henrik.pedersen wrote:

> Hejsan
> 
> May 14 08:44:58 Tux1 kernel: 10.3.97.1 sent an invalid ICMP error to a
> broadcast.
> 
> Følgende besked blier ved med at komme i min message log.
> Nogen der har en ide om hvad det kan være ?
> Det drejer sig om en Rødhætte 7,2
> 
> Henrik
et lille kig i kerne koden (/usr/src/linux/net/ipv4/icmp.c) afslører 
følgende:

        /*
         *      Check the other end isnt violating RFC 1122. Some routers 
send
         *      bogus responses to broadcast frames. If you see this message
         *      first check your netmask matches at both ends, if it does 
then
         *      get the other vendor to fix their kit.
         */
 
        if (!sysctl_icmp_ignore_bogus_error_responses)
        {
 
                if (inet_addr_type(iph->daddr) == RTN_BROADCAST)
                {
                        if (net_ratelimit())
                                printk(KERN_WARNING "%d.%d.%d.%d sent an 
invalid ICMP error to a broadcast.\n",
                                NIPQUAD(skb->nh.iph->saddr));
                        return;
                }
        }

Så hvis din netmaske er sat korrekt, kan du trygt sætte din box til at 
ignore bogus error messages (net.ipv4.icmp_ignore_bogus_error_responses = 1 
i /etc/sysctl.conf og sysctl -p), da jeg tvivler på at du kan få router 
producenten til at fixe problemet - medmindre der måske er en update til 
routeren allerede :-)

p.s. du kan selv checke koden for sådanne ting, ved at bruge f.ex.
grep -irl "sent an invalid ICMP error to a broadcast" /usr/src/linux/*

-- 
Regards,
Klavs Klavsen

-------------| This mail has been sent to you by: |------------
              Klavs Klavsen - Open Source Consultant 
                 kl@xxxxxxx - http://www.vsen.dk

    Get PGP key from www.keyserver.net - Key ID: 0x586D5BCA 
Fingerprint = A95E B57B 3CE0 9131 9D15 94DA E1CD 641E 586D 5BCA
--------------------[ I believe that... ]-----------------------
It is a myth that people resist change. People resist what other
people make them do, not what they themselves choose to do...
That's why companies that innovate successfully year after year
seek their peopl's ideas, let them initiate new projects and
encourage more experiments.            -- Rosabeth Moss Kanter