Hi,
I'm sure this is going to be difficult to diagnose - so I need some
help to figure out where to start.
Setup:
NetBSD -current (3.99.7) on Sparc64.
IPv6-over-GRE-over-IPv4 tunneling
tcpdump HEAD from CVS
system libpcap
$ ./tcpdump -V
tcpdump version 3.9-PRE-CVS
libpcap version 0.8.3
(this is because using libpcap-3.9-PRE-CVS makes tcpdump core dump, for
whatever reason??!)
Sniffing on the LAN for "host <remote address of tunnel>" gives:
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on hme0, link-type EN10MB (Ethernet), capture size 65535 bytes
16:14:04.595494 IP 172.30.1.153 > 193.149.44.208: GREv0, length 60: IP6
2001:608:8003::1 > 2001:608:4::3: ICMP6, echo request, seq 0, length 16
16:14:04.700420 IP 193.149.44.208 > 172.30.1.153: GREv0, length 60: IP6
2001:608:4::3 > 2001:608:8003::1: ICMP6, echo reply, seq 0, length 16
16:14:05.595419 IP 172.30.1.153 > 193.149.44.208: GREv0, length 60: IP6
2001:608:8003::1 > 2001:608:4::3: ICMP6, echo request, seq 1, length 16
16:14:05.746677 IP 193.149.44.208 > 172.30.1.153: GREv0, length 60: IP6
2001:608:4::3 > 2001:608:8003::1: ICMP6, echo reply, seq 1, length 16
-> perfect, this is exactly how it should be.
Sniffing on the tunnel interface (gre0) gives:
[EMAIL PROTECTED]:/home/gert/cdp/tcpdump$ SU ./tcpdump -n -s0 -i gre0
tcpdump: WARNING: gre0: no IPv4 address assigned
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on gre0, link-type NULL (BSD loopback), capture size 65535 bytes
16:16:28.835438 IP6 2001:608:8003::1 > 2001:608:4::3: ICMP6, echo request, seq
0, length 16
16:16:28.937041 IP6 , wrong link-layer encapsulationbad-hlen 0
16:16:29.835377 IP6 2001:608:8003::1 > 2001:608:4::3: ICMP6, echo request, seq
1, length 16
16:16:29.947910 IP6 , wrong link-layer encapsulationbad-hlen 0
-> which is weird. Outgoing packets are properly decoded, incoming
packets are not properly displayed.
With "-X", the packets look like this:
16:32:36.925380 IP6 2001:608:8003::1 > 2001:608:4::3: ICMP6, echo request, seq
1, length 16
0x0000: 6000 0000 0010 3a40 2001 0608 8003 0000 `.....:@........
0x0010: 0000 0000 0000 0001 2001 0608 0004 0000 ................
0x0020: 0000 0000 0000 0003 8000 1c21 ecc8 0001 ...........!....
0x0030: 42e6 4984 000e 1e34 B.I....4
16:32:37.024946 IP6 , wrong link-layer encapsulationbad-hlen 0
0x0000: 6000 0000 0010 3a3d 2001 0608 0004 0000 `.....:=........
0x0010: 0000 0000 0000 0003 2001 0608 8003 0000 ................
0x0020: 0000 0000 0000 0001 8100 1b21 ecc8 0001 ...........!....
0x0030: 42e6 4984 000e 1e34 B.I....4
(The pinging itself works fine, so the issue is not "corrupted packets"
but more "corrupted signalling kernel->libpcap" or such).
What could be causing this effect? How can I narrow this down, and
get it fixed / fix it?
gert
--
USENET is *not* the non-clickable part of WWW!
//www.muc.de/~gert/
Gert Doering - Munich, Germany [EMAIL PROTECTED]
fax: +49-89-35655025 [EMAIL PROTECTED]
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