As a start use CheckIPHeader "DETAILS true" configuration setting and have a look at the drop_details handler information for more detailed information on why CheckIPHeader dropped the packet.
On Mon, Nov 23, 2009 at 10:56 PM, Latency Buster <[email protected]>wrote: > I am trying to separate out multicast packets. Before feeding to the > IPClassifier, when I pass it through CheckIPHeader(), I recv lots of > IP HEader Failed Messages. The input packets are multicast packets but > the IP header is clean (as looked via wireshark). Any insights why > this might occur? > > > > ------------------ CONFIG --------------------------------------- > inputDevice::FromDump(/home/click/test.pcap, END_AFTER 0.2); > > inputDevice->c0::Classifier (12/8100 /* dot1Q */, 12/0800 /* > 'normal ip packets */, - /* everything else including ARP */); > > // Filter out multicast packets > ip_classifier::IPClassifier(224.0.0.0/4 and ip proto udp, - /* > everything else */); > > > c0[0]-> Print("We received 802.1Q Packets.. Discarding") -> Discard; > c0[1]-> ip::CheckIPHeader (14, INTERFACES 224.0.0.0/4, VERBOSE > true,CHECKSUM false); > c0[2]-> Discard; > > ip[0] -> ip_classifier; > ip[1] -> Print("IP header Failed..", 20) -> ToDump > (/home/click/badip.pcap); > > ip_classifier[0]->Print("These are valid Multicast Packets for NAT") -> > Discard; > ip_classifier[1]->Print ("This will all go to LINUX Host")-> Discard; > > ----------------------------- END OF CONFIG -------------------------- > > click-user:~/ click test_mcast.click > > IP header Failed..: 68 | 01005e43 0d0d001b 0ded1180 08004500 > 05da3e82 00001c11 337fac15 7e2cefc3 0d0dbb60 138905c6 364d0000 > 04534b07 0d32000f 30490000 00000000 00010000 13890000 > > IP header Failed..: 68 |01005e43 0d0d001b 0ded1180 08004500 05da3e83 > 00001c11 337eac15 7e2cefc3 0d0dbb60 138905c6 4ccb0000 04544b07 > 0d330000 19d80000 00000000 00010000 13890000 > _______________________________________________ > click mailing list > [email protected] > https://amsterdam.lcs.mit.edu/mailman/listinfo/click > _______________________________________________ click mailing list [email protected] https://amsterdam.lcs.mit.edu/mailman/listinfo/click
