Messages in this thread | | | Date | Thu, 28 Oct 2004 20:07:21 -0500 | From | parker@citynetw ... | Subject | ICMP ttl-exceeded packets not sourced correctly |
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I think there's a problem with the ICMP code...
Say you have a router, and it's multihomed to two different isp's, say cogentco.com and qwest.net as your upstreams. On your cogent interface, you have the ip address on the /30 assigned by cogent, with reverse dns being blahblah.demarc.cogentco.com on the qwest interface. Same story with qwest, with reverse dns being whatever.qwest.net. Now let's say someone out on the internet with ip address of 1.1.1.1 runs a traceroute into your network and his incoming path to your network comes over qwest. Your router's hop should source its ICMP ttl-exceeded code (the traceroute hop) on its qwest /30 ip address, because thats where the traceroute got triggered. ICMP ttl-exceeded code's response should not be originated from the interface holding the route, but should be origianted from the interface that got hit with the traceroute.
-- Bubba Parker Systems Administrator CityNet LLC http://www.citynetinfo.com/ - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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