Setting up a switch in class..crashed and burned

Image above "Redneck networking" :P

In this lab we had to Set up a network on a switch using 160.20.0.0 with a subnet mask 255.255.240.0

4 bits are being used by this network.
Our task was to set up our IP’s on the 4^th subnet I was assigned #7 on this range.
At first I made a huge mistake when I got the end range in the 3^rd range I excluded one of the host bits. So what I did was 0011 1111.11111110 this gave me 160.20.63.254 as my end range & 160.20.63.255 as the broadcast for this range. So with these figures I started the 4^th range with 160.20.64.0…WRONG. What I should have done was not include the Host part into the end range here what it should have looked like 0010 1111.11111110 this would have gave me 160.20.47.254 for my end range & 160.20.47.255 for my broadcast. With 160.20.48.0 as the correct 4^th subnet. Once I had the correct subnet number I had to set up my PC with the proper IP. To do this I had to go to start/settings/network connections/properties on my LAN/ properties IPV4.

See image below

Once I got my IP set up I had to ping the rest of the class, (to do this open command prompt and type ping IP number you wish to ping should look like this 160.20.48.3) but for some reason they were not able to ping me, even though my firewall was off. My teacher looked over my settings and didn’t find anything wrong. He suggested a reboot, but this still did not fix the problem. I was never able to find out why the rest of my class was unable to ping me.

(Commands Lab)It's all about commands baby

This week I thought I would try and do this lab as a video lab. I hope you like it.

The Three little Cisco Switches

The Three little Cisco Switches

The first switch I looked up was the ultra-light SD205 5 port 10/100 switch. This thing only weights 8oz and is around 3 ½” square, 1 inch thick. I never would have thought that Cisco would have built such a small switch. This switch has 5 RJ-45 type ports each port has auto cable detection, so it will know if you have plugged in a cross-over cable or a straight though cable. This port also has auto speed negotiating so it will know if your devices run at 10mbps or 100mbps. Even though this switch was designed for small businesses it still has a lifetime warranty on hardware and a 1year warranty on fans and power supply. I found this switch list for as little $23 and as much as $39.99

The next switch I looked at was the Catalyst 2960 100/1000 switch 8, 24 or 48 port switch. This is a real switch designed to be put into a rack designed with the entry-level network in mind but it does provide enhanced LAN services. The only ports I seen on this switch was the RJ-45s. It has SNMP (Simple Network Management Protocol), supports PoE (Power of Ethernet), a standalone fixed-configuration and something I thought was neat is a built in redundant power system for two ports. This type of switch will let you stack up to 16 switches and you get free software updates for life. The warranty is not much better then the SD205 you get “Limited Lifetime Hardware Warranty”. The prices I found for this switch series was from $70 to $2000.

The last switch I picked for my Blog is the mother of all Cisco switches. I’d like to introduce the Nexus 7000 (heck even the name is cool). This thing has everything from a modular design to it’s own O.S (Cisco NX) it was designed for data centers. Supports scalability and is designed to maintain zero down time environments. It also is “engineered for foresight to enable the adoption of new technologies in an incremental, cost-effective manner” this is neat that they can for see what will be coming out next. Wow this is some serious switching!!!!
The basic tower with nothing it costing around $11,000 and the modules I seen listed from $16,000 to $44,000!!!!!! Holy cow Batman that some real doe!!

I thought this was neat if you would like to see a nice 3d model of it that you can spin all around and look at from any angle got to this link http://www.cisco.com/en/US/prod/collateral/switches/ps9441/ps9402/ps10098/3d_model_7k-18.html

Router Lab: Setting the DHCP ranges.

Router Lab

Today we had to set the ranges on a D-link Dir-61S router.

First thing I had to do was to reset the router to the factory defaults so I would be able to get into the settings. To do this you take a small pin and stick it in a hole (In the back of the router) for 6 secs.
Now to get to the settings you need to use your browser and type in the default gateway in the address bar. If you don’t have the manual and are unsure of this number go to start type cmd then type ipconfig/renew (or /all) your find the number you need next to “Default Gateway”.

Most of the time the default password is admin or leave the line blank. If this doesn’t work do a quick Google search of your router to find this info.

For this lab I had to set the routers DHCP IP ranges from 192.168.0.2~ 192.168.0.5 and the router itself to 192.168.0.1 for the first try. Then I had to set the routers DHCP IP ranges from 10.0.0.2~10.0.0.5 and the router itself to 10.0.0.1 for the 2nd try. After you set the setting you have to update the router you do this by hitting the update button. After you set the router’s setting go back to command prompt on your pc and type ipconfig/renew. Now you will have an IP with-in the IP range you set. We tried to hook up to the internet with the 2^nd IP range but it was in conflict with the school’s network so we had to go back the first IP ranges to reach the net. See the photos below for some screen shots of this easy lab.

Editing the Host file & renewing an IP address

Editing the host file

One of our labs today was to edit the Host file. Since we have to use an IP address to get to our blackboard, the named url will not work, when we use the class room computers. Our teacher wanted us to edit our host file so that we could use a simple word to get to blackboard without having to type the IP each time.

When using vista the first thing you need to do is open notepad as an administrator…see image below.

Now we need to find the host file it is ///System32/drivers/etc ..see image below..

Now I had to insert the target IP (the one we used for black board) with a space then the name I wanted to use to represent that IP, I used “myblackbord.” …see image below.

Now save the file, if you can’t it because you didn’t open notepad as an administrator. Now open your web browser and type the word you used and watch you page load up.

Release/Renew an IP

The next lab was to release and renew our IP address. Again for this to work you need to open command prompt as an admin; just like you did for notepad. Once you have command prompt open type ipconfig/release..see image below.

For the last step you need to renew you IP address so type ipconfig/renew…see image below.

Wireshark Lab

This week our lab was to use a free packet capture program called Wireshark.
The first packet I caught was a TCP packet. Wireshark was able to give all sorts of information on this packet. Below is a few screen shot of the TCP packet I got.


The source IP was 10.40.1.102 (This is the PC I use at school); the destination IP was 64.233.169.105 (I quick search of this IP found it goes to Google). The source port was 49475, a quick search of the internet was unable to show what application was using this port, the destination port was 80 this port is used for HTTP and is on the application layer. The flag for the port was 0x02 (syn), basically the sender (my PC) is requesting a synchronization of the of the sequence number. Another thing listed was the TTL(time to Live) for this packet it was 128. This means that this is the limit on the period of time or number of transmissions that this packet can experience before it will be discarded. The Differentiated services field was (DSCP 0x00: Default; ECN: 0x00) I looked and look on the internet for what this meant, and I was unable find to find out….so I’m still in the dark on what this really means. But I will keep looking and when I find out I will update the blog with what it is. The 4 other values for this was. 0000 00.. = Differentiated Services Codepoint: Default (0x00), .... ..0. = ECN-Capable Transport (ECT): 0,.... ...0 = ECN-CE: 0, Total Length: 52. Ok lets move on..to the protocol field, this packet was set to TCP (0x06), this means it was using a transmission protocol. Onther cool thing listed for this packet was the MAC address of the source (00:16:76:d6:e0:2f) and destination (00:04:c0:ee:9b:ff ) Nodes. A few things I found interesting was that the frame listed the make of the processer and it’s physical address in this case a Intel_d6:e0:2f. Thought that was really neat.

The next packet we had to analyze was a UDP packet.

In this packet the source port was 2457 this is used by “rapido-ip”. The destination port was 53 this is used by the domain name system. The Source IP and Mac was 192.168.1.7 & 00:24:1d:2d:4a:2b both these number identify that my home PC was the source of this packet. The destination IP and MAC was 192.168.1.1 and 00:1b:2f:02:8a:0e.both these number identify my home router as the destination for this packet.
The flag for this packet was list as “standard query”0X0100. The TTL(time to Live) for this packet it was 128. This means that this is the limit on the period of time or number of transmissions that this packet can experience before it will be discarded (this was the same as my last packet).
The framing used was PTR (Domain name pointer). Other things list of interest was
all the Protocols in the frame were listed, eth:ip:udp:dns. The Coloring Rule Name was UDP. The frame number was 3& it’s length was 84 bytes with a capture length of 84 bytes.

I was supposed to find a TCP packet with a three way handshake, my home PC did not show any in the hour and half I used Wireshark.

Next packet was an ARP.

The Source IP and Mac was 192.168.1.1 & 00:1b:2f:02:8a:0e both these number identify that my home network’s router was the source of this packet. The destination IP and MAC was 192.168.1.7 and 00:24:1d:2d:4a:2b both these number identify my home PC as the destination for this packet.
This address was used because it was a packet between my PC and my network’s router. Other stuff the ARP frame had that was cool was it included the date and time of the packet as well as the frame number. I also told me how big it was in this case it was 64 bytes. Another thing that was listed in the frame was the protocols that was used for this packet, for me this was the most useful since I understand that.

Wireshark was kind of neat to use I learned a little bit from it, and each time I study it I seem to pick up just a little bit more. The biggest thing I learned from Wireshark is that networks exchanges A LOT of data very rapidly. I wouldn’t have imaged that some many different packets using different protocols would be going between my PC and the rest of the network. Over all Wireshark was kind of neat to work with but on the other hand it only added to my confusion. I now fell more lost in the word of networking, how will I ever memorize ALL THIS data! I not even sure what I was looking up, most site use some kind of jargon and talked in terms I have yet to understand. To be honest this has me questioning if this is the line of work for me.

I’m sure this program is useful. I kept running into website where people posted the information like we got from Wireshark in hopes of solving a problem they were having. So I sure it is used as a good diagnostic tool.