This is our old Q&A Site. Please post any new questions and answers at ask.wireshark.org.

I am trying to go from my web address aseanenglish.info to a virtual machine.

I have Ubuntu 16.04 as a guest in Virtual Box.

I have set up port forwarding on my router so that traffic on ports 1935 and 5080 get directed to this virtual machine.

I have also tried setting up port forwarding from the router to the host and configuring port forwarding in Virtual Box so that my guest virtual machine sees the traffic on 1935 and 5080.

I receive the Frame Check Sequence Incorrect error in my capture on the host computer.

But what does it mean and what causes it ?

Wireshark from Windows Host

asked 27 Sep '16, 06:54

kam2700's gravatar image

kam2700
6114
accept rate: 100%

edited 27 Sep '16, 06:56


It turns out the problem was when port forwarding from the router I had to enable TCP/UDP then it worked.

permanent link

answered 29 Sep '16, 03:15

kam2700's gravatar image

kam2700
6114
accept rate: 100%

I think this is a capture problem - I've seen packets like this when capturing VMs on the host, and they're not really being sent to the network. No idea what causes those.

What I would recommend is to capture the traffic with a device that isn't involved in the communication (dedicated capture laptop/PC) via TAP or SPAN port. Otherwise your readings are incorrect.

permanent link

answered 27 Sep '16, 07:07

Jasper's gravatar image

Jasper ♦♦
23.8k551284
accept rate: 18%

Big chance the capture engine gets confused by real vs virtualised network interface capabilities, and likely assumes the FCS is there while it's not. Try modifying the Ethernet dissector preferences (disable: Assume packets has FCS and Validate the Ethernet checksum if possible).

permanent link

answered 27 Sep '16, 07:17

Jaap's gravatar image

Jaap ♦
11.7k16101
accept rate: 14%

Your answer
toggle preview

Follow this question

By Email:

Once you sign in you will be able to subscribe for any updates here

By RSS:

Answers

Answers and Comments

Markdown Basics

  • *italic* or _italic_
  • **bold** or __bold__
  • link:[text](http://url.com/ "title")
  • image?![alt text](/path/img.jpg "title")
  • numbered list: 1. Foo 2. Bar
  • to add a line break simply add two spaces to where you would like the new line to be.
  • basic HTML tags are also supported

Question tags:

×41
×7

question asked: 27 Sep '16, 06:54

question was seen: 1,267 times

last updated: 29 Sep '16, 03:15

p​o​w​e​r​e​d by O​S​Q​A