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Is there a way to get wireshark to capture packets sent from/to localhost?

When I monitor traffic going from my computer to another, or from another computer to my computer, then it works. But from localhost to localhost does not register anything.

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what platform? Windows? Mac? Linux? –  Jeff Atwood Jun 9 '09 at 22:51
    
Particularly on Windows –  Brian R. Bondy Jun 9 '09 at 22:55
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4 Answers

up vote 18 down vote accepted

There's a WIKI Entry about exactly this issue on the wireshark homepage.

They also mention specifics about the loopback interface regarding Windows - you could be running just into that.

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Care to elaborate why this is getting voted down? –  Server Horror Jun 9 '09 at 22:48
    
I did not vote down but probably because even basic questions that have easily findable solutions are encouraged on this site and stackoverflow.com. The answer is good but the tone is not. Consider editing it and I think it will be voted up. –  Brian R. Bondy Jun 9 '09 at 22:53
    
I'm sorry I'm not a native english speaker (guess I'm not the only one). I'll try to think about that in the future. –  Server Horror Jun 9 '09 at 22:55
    
+1 for knowing and adding the link. –  l0c0b0x Jun 9 '09 at 23:00
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Might want to add the quick quote "You can't capture on the local loopback address 127.0.0.1 with a Windows packet capture driver like WinPcap." from the linked page to save us the suspense... –  andersoj May 28 '12 at 11:44
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In Wireshark you need to choose the lo0 interface... not En0 or En1.

Go to:

  • Show the capture options
  • Under "Interface" choose: lo0
  • Capture and you'll see a bunch of 127.0.0.1 communication
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on windows, of course, i dont believe you can do that without somehow adding a loopback interface manually. –  djangofan Apr 21 '10 at 22:02
    
yes, the document said: you can capture on the loopback interface on Linux, on various BSDs including Mac OS X, and on Digital/Tru64 UNIX, and you might be able to do it on Irix and AIX, but you definitely cannot do so on Solaris, HP-UX, or Windows. –  Allan Ruin Mar 19 at 6:43
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you can use RawCap Application to capture loopback packets and save them in a pcap file ... and then you can open it using Wireshark

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You want to run wireshark on the "lo" interface or on "any".

With tshark or tcpdump you can use the -i option:

# tcpdump -i any port http

(This is mostly applicable to Linux)

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