Linux, FreeBSD, Juniper, Cisco / Network security articles and troubleshooting guides

FAQ

It is currently Tue Oct 03, 2023 4:45 pm

ROOT ‹ FreeBSD, Linux and AIX ‹ TCP/IP Networking ‹ Sendip packet crafting tool: How to send bad checksum TCP packets

Internet Protocol, Transport Control Protocol, Network protocols, Routing, Routers, IP aliases, Routes, Ethernet

Post a reply

3 posts • Page 1 of 1

Sendip packet crafting tool: How to send bad checksum TCP packets

« Previous topic | Next topic »

Author

Message

mandrei99

Post subject: Sendip packet crafting tool: How to send bad checksum TCP packets | Posted: Tue Jan 28, 2014 5:52 am

Joined: Tue Aug 04, 2009 9:16 am
Posts: 250

Sendip packet crafting tool: How to send bad checksum TCP packets

Following sendip command will send TCP packets with bad checksum.

Code:

# sendip  -p ipv4 -p tcp -is 10.0.1.2 -iv 4 -ip 6 -ic 2342352 -ts 1000 -td 80 -tc 234235235 172.16.2.2

Following a tcpdump snapshot of the packet:

Code:

10:49:53.952912 IP (tos 0x0, ttl 255, id 61754, offset 0, flags [none], proto TCP (6), length 40)
    10.0.1.2.1000 > 172.16.2.2: Flags [S], cksum 0x2563 (incorrect -> 0xd933), seq 2806054912, win 65535, length 0

See the incorrect tcp checksum.

			Tweet
Follow @IvordeCom

You might also be interested in:
How to generate GRATUITOUS ARP REQUEST on FreeBSD using nemesis packet crafting tool. FreeBSD + IPerf send multicast source traffic via specific interface. TCP ack after two packets. Tcpdump: How to capture first two packets of tcp conversation (SYN/SYN+ACK). TCP first packet loss. TCP first packet loss. FreeBSD list the outgoing interface for packets to a specific IP destination. Linux list the outgoing interface for packets to a specific IP destination.

Top

ladlasheikh

Post subject: Re: Sendip packet crafting tool: How to send bad checksum TCP packets | Posted: Fri Mar 27, 2015 7:40 am

Joined: Fri Mar 27, 2015 7:13 am
Posts: 1

will send TCP packets with bad checksum?great

Top

lizamare

Post subject: Re: Sendip packet crafting tool: How to send bad checksum TCP packets | Posted: Wed Apr 15, 2015 2:02 am

Joined: Tue Apr 14, 2015 11:55 am
Posts: 1

Ok i understand what you are saying but i think there should be more comments about the topic started initially, Thanks

_________________
imran

Top

Post a reply

3 posts • Page 1 of 1

Topics		Author	Replies	Views	Last post
Topics related to - "Sendip packet crafting tool: How to send bad checksum TCP packets"
	How to generate GRATUITOUS ARP REQUEST on FreeBSD using nemesis packet crafting tool	admin	0	5218	Thu Feb 23, 2012 4:49 am admin
	FreeBSD + IPerf send multicast source traffic via specific interface	mandrei99	3	6184	Sat Apr 11, 2015 5:28 am areeba
	TCP ack after two packets	MichaM	2	2802	Tue Dec 13, 2016 10:04 am humdrum
	Tcpdump: How to capture first two packets of tcp conversation (SYN/SYN+ACK)	debuser	0	29934	Wed Jun 13, 2012 5:32 am debuser
	TCP first packet loss	satk	1	2160	Tue Jan 22, 2013 9:20 am admin
	TCP first packet loss	satk	0	1872	Wed Dec 12, 2012 4:44 am satk
	FreeBSD list the outgoing interface for packets to a specific IP destination	mandrei99	0	2905	Mon Jul 22, 2013 10:12 am mandrei99
	Linux list the outgoing interface for packets to a specific IP destination	mandrei99	0	3251	Mon Jul 22, 2013 10:17 am mandrei99

Who is online

Users browsing this forum: No registered users and 0 guests

You can post new topics in this forum
You can reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Jump to:

Channel list

ROOT ‹ FreeBSD, Linux and AIX ‹ TCP/IP Networking

Delete all board cookies | The team | All times are UTC - 5 hours [ DST ]