Messages in this thread | | | Date | Sat, 2 Sep 2000 17:59:30 +0300 | From | Matti Aarnio <> |
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On Sat, Sep 02, 2000 at 04:12:04PM +0200, Elmer Joandi wrote: .... > There is another big problem like that... > tunnels actually do not work on todays real internet... > MTU 1500 is so much a standard that it starts killing tunnels. > MTU < 1500 is not a working solution today thanks to (mostly > linux based ? ) broken firewalls
It is due to knee-jerk ICMP blocking settings at firewalls/routers.
From personal experience I can say that even cisco router training includes example of: "block ALL of ICMP", which of course makes TCP PMTU discovery non-functional. (That was 3 years ago when PMTU discovery was a new thing, but still..)
Another issue are still existing SLIP links with mismatching link MTUs at each side.
> elmer.
/Matti Aarnio - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org Please read the FAQ at http://www.tux.org/lkml/
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