[Click] IP header check failed:

[Beyers Cronje]

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 <latencybuster at gmail.com>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
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