Network traffic analysis

Setting up a chinese IP camera without manual

May 13, 2016Tags: networking wireshark IP-camera IP-address

This post is probably a no-brainer for quite a lot of people. And it should have been for me too. I don’t know if my brain was just not working from the dry and hot el niño weather, but it took me quite a while to figure this out. Since chances are there are others with the same problem, I thought it’d be worth to write it up.

My boss bought a few IP-camera’s on Ali-Express together with a recorder to monitor some areas with expensive equipment. I won’t go into the security of these types of camera’s here. And of course the cheap stuff from Ali-Express comes in an unmarked box without any manuals. There’s also no brand to be found on the camera. Normally it is a matter of pride to not need manuals. But the problem with IP camera’s is that you need to know their network settings somehow. That is where I ran into trouble.

The camera’s have both a wired and wireless connection available. I was hoping the camera would be set to dynamic IP, so it would pickup an IP address from the DHCP server on my router, and I could see it in the router status page when I connected it with a wire. No such luck though. The next thing I tried was setup a DHCP server on my laptop. It’s pretty straightforward to install dnsmasq, and the only settings you need to adjust are the interfaces directive (make sure it’s not running on your wifi interface and mess up the wifi) and DHCP-range directive. And you need to set a static IP in the same sub-net for your wired network card. I’m not going into the details for this, but suffice it to say this didn’t work either. So clearly the IP-camera wasn’t set for a dynamic IP. I tried a few of the simple IP addresses like 192.168.0.2 192.168.1.2, etc but none worked. I was ready to give up what my brain finally kicked into gear: wireshark.

I have used wireshark plenty of times before to analyse network traffic. It is an awesome tool. It allows you to see all network traffic passing through your network interfaces. I did see the light on the wired network interface of the camera blinking, so I knew it was trying to communicate through the network. So I connected the camera with a cable straight into the network card of my laptop. I ran wireshark on that network interface and looked at the traffic coming by. Very quickly I noticed ARP-packets where an IP-address 192.168.1.136 was asking who has 192.168.1.1. This means that there is a device with IP-address 192.168.1.136 who is looking to contact IP-address 192.168.1.1. Chances are that this is the camera looking for a router to contact the internet. Indeed the camera’s turned out to be configured with NTP enabled to sync it’s hardware clock with a server on the internet, and it was trying to get on the internet. So now I knew the IP-address of the camera was 192.168.1.136. From that point onward it was straightforward again. Just set a static IP (192.168.1.2) on my laptop wired network interface, have a cable between the camera and the laptop, and I could access the web-interface of the camera on http://192.168.1.136.

Configuring could finally commence. It took me way to long to realize to get wireshark. It was pretty easy once I remembered.

Mechanical properties of material

Mechanical properties of material:There are mainly two types of materials. First one is metal and other one is non metals. Metals are classified into two types : Ferrous metals and Non-ferrous metals.

Ferrous metals mainly consist iron with comparatively small addition of other materials. It includes iron and its alloy such as cast iron, steel, HSS etc. Ferrous metals are widely used in mechanical industries for its various advantages.

Nonferrous metals contain little or no iron. It includes aluminum, magnesium, copper, zinc etc.

Most Mechanical properties are associated with metals. These are

#1. Strength:

The ability of material to withstand load without failure is known as strength. If a material can bear more load, it means it has more strength. Strength of any material mainly depends on type of loading and deformation before fracture. According to loading types, strength can be classified into three types.

• a. Tensile strength:
• b. Compressive strength:
• 3. Shear strength:

According to the deformation before fracture, strength can be classified into three types.

• a. Elastic strength:
• b. Yield strength:
• c. Ultimate strength:

#2. Homogeneity:

If a material has same properties throughout its geometry, known as homogeneous material and the property is known as homogeneity. It is an ideal situation but practically no material is homogeneous.

#3. Isotropy:

A material which has same elastic properties along its all loading direction known as isotropic material.

#4. Anisotropy:

A material which exhibits different elastic properties in different loading direction known as an-isotropic material.

#5. Elasticity:

If a material regain its original dimension after removal of load, it is known as elastic material and the property by virtue of which it regains its original shape is known as elasticity.

Every material possess some elasticity. It is measure as the ratio of stress to strain under elastic limit.

#6. Plasticity:

The ability of material to undergo some degree of permanent deformation without failure after removal of load is known as plasticity. This property is used for shaping material by metal working. It is mainly depends on temperature and elastic strength of material.

#7. Ductility:

Ductility is a property by virtue of which metal can be drawn into wires. It can also define as a property which permits permanent deformation before fracture under tensile loading. The amount of permanent deformation (measure in percentage elongation) decides either the material is ductile or not.

Percentage elongation = (Final Gauge Length – Original Gauge Length )*100/ Original Gauge Length

If the percentage elongation is greater than 5% in a gauge length 50 mm, the material is ductile and if it less than 5% it is not.

#8. Brittleness:

Brittleness is a property by virtue of which, a material will fail under loading without significant change in dimension. Glass and cast iron are well known brittle materials.

#9. Stiffness:

The ability of material to resist elastic deformation or deflection during loading, known as stiffness.  A material which offers small change in dimension during loading is more stiffer. For example steel is stiffer than aluminum.

#10. Hardness:

The property of a material to resist penetration is known as hardness. It is an ability to resist scratching, abrasion or cutting.

It is also define as an ability to resist fracture under point loading.

#11. Toughness:

Toughness is defined as an ability to withstand with plastic or elastic deformation without failure. It is defined as the amount of energy absorbed before actual fracture.

#12. Malleability:

A property by virtue of which a metal can flatten into thin sheets, known  as malleability. It is also define as a property which permits plastic deformation under compression loading.

#13. Machinability:

A property by virtue of which a material can be cut easily.

#14. Damping:

The ability of metal to dissipate the energy of vibration or cyclic stress is called damping. Cast iron has good damping property, that’s why most of machines body made by cast iron.

#15. Creep:

The slow and progressive change in dimension of a material under influence of its safe working stress for long time is known as creep. Creep is mainly depend on time and temperature. The maximum amount of stress under which a material withstand during infinite time is known as creep strength.

#16. Resilience:

The amount of energy absorb under elastic limit during loading is called resilience. The maximum amount of the energy absorb under elastic limit is called proof resilience.

#17. Fatigue Strength:

The failure of a work piece under cyclic load or repeated load below its ultimate limit is known as fatigue. The maximum amount of cyclic load which a work piece can bear for infinite number of cycle is called fatigue strength. Fatigue strength is also depend on work piece shape, geometry, surface finish etc.

#18. Embrittlement:

The loss of ductility of a metal caused by physical or chemical changes, which make it brittle, is called embrittlement.