Linux-kernel mailing list archive 1997-11,: IPv4 checksum errors

# IPv4 checksum errors

Fred Leeflang (fredl@dutchie.org)
Tue, 25 Nov 1997 18:39:12 -0800 (PST)

- Messages sorted by: [ date ][ thread ][ subject ][ author ]
- Next message: Stephen Williams: "Re: Memory management"
- Previous message: Spir: "Re: Memory management"
- Next in thread: Fred Leeflang: "Re: IPv4 checksum errors"
- Maybe reply: Fred Leeflang: "Re: IPv4 checksum errors"
- Reply: Shane Anderson: "Re: IPv4 checksum errors"

Hi everybody,

I recently sent this question to linux-net only, but have not gotten any
reply so far, so this time I'll bring it in a somewhat larger audience,
it's really weird, I saw these in my dmesg output:

TCPv4 bad checksum from 205.229.196.5:0017 to 208.196.141.34:28ee,
len=20/20/40
TCPv4 bad checksum from 128.214.248.6:12e0 to 208.196.141.34:0019,
len=1349/1349/1369
TCPv4 bad checksum from 128.214.248.6:12e0 to 208.196.141.34:0019,
len=425/425/445
TCPv4 bad checksum from 128.214.248.6:0ef2 to 208.196.141.34:0019,
len=1480/1480/1500

The first address is from my ISP, so I can imagine something with that,
the 128.* numbers are nic.funet.fi.... I don't remember contacting there
lately at all, and I'm curious where these packets come from, or issit
possible that the packet is so malformed that the IP address is not
reliable anymore? Can this in any way be related to teardrop attack? Let
me know if I can give more information.

Thanks,
Fred Leeflang

- Next message: Stephen Williams: "Re: Memory management"
- Previous message: Spir: "Re: Memory management"
- Next in thread: Fred Leeflang: "Re: IPv4 checksum errors"
- Maybe reply: Fred Leeflang: "Re: IPv4 checksum errors"
- Reply: Shane Anderson: "Re: IPv4 checksum errors"