Date: Wed, 26 Nov 1997 18:19:43 +0100 (MET) From: Luigi Rizzo <luigi@labinfo.iet.unipi.it> To: hackers@freebsd.org Subject: udp question related to icmp... Message-ID: <199711261719.SAA07459@labinfo.iet.unipi.it>
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Hi, just now i tried to use connect on a SOCK_DGRAM to avoid having to specify the destination address every time. Things worked perfectly with multicast, and by pure luck they worked while i was doing testing on my machine. When i tried with a remote machine which was not listening, a problem came out: the remote machine was (presumably) sending back ICMP port unreachable, which caused the kernel to disable further writes to that socket, so after the first few packets, nothing went out anymore. Further investigation in vat sources (net.cc) shows that the problem is well known (although not mentioned in the manpages). I was almost going to apply the fix to the kernel mentioned in vat's net.cc when I realized that after all it is not such a terrible idea to report failures (due to ICMP port unreachable) up to the application, if nothing else to avoid flooding the net with undesired data. So... I started writing this email looking for a fix, but now I guess I just have to point this behaviour to your attention... Cheers Luigi -----------------------------+-------------------------------------- Luigi Rizzo | Dip. di Ingegneria dell'Informazione email: luigi@iet.unipi.it | Universita' di Pisa tel: +39-50-568533 | via Diotisalvi 2, 56126 PISA (Italy) fax: +39-50-568522 | http://www.iet.unipi.it/~luigi/ _____________________________|______________________________________
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