Packet tracer issue

Sale2506

Hi, I am new to this forum and my english is not so good, but I'll try to present my problem as good as I can, and I hope there is someone who can find some free time and help me.

I'm on ccna 2 and at the moment I'm studying for my final pratice part of exam, and as I study, I ran on a problem in a packet tracer pratcice file. If someone else can acces ccna2 files, correct name of the practice is Lab 2.8.2 Challenge Static Route Configuration. Let me present the task:

The addressing for the LAN connected to the ISP router and the link between the HQ and ISP routers has already been completed. You have been given the 192.168.2.0/24 address space to complete the network design. Subnet this network to provide enough IP addresses to support 60 hosts.

<img src="http://www.fileden.com/files/2007/6/15/1180214/PT.JPG" alt="PT.JPG" />

Assign subnet 1 to the LAN attached to HQ.
· Assign subnet 2 to the WAN link between HQ and Branch.
· Assign subnet 3 to the LAN attached to Branch.
· Subnet 0 will be available for future expansion.

So I subnetted address 192.168.2.0 on three subnets, 1st - 192.168.2.1 255.255.255.192 (63-2 hosts) for HQ Lan subnet, and I ran on issue right away, in scenario it says to assign subnet 2 to wan between HQ and Branch, but when I assign the address 192.168.2.65 and 66 255.255.255.252 on s0/0/0 interfaces on both routers, I cannot assign the third subnet with an IP of 192.168.2.67 or 68,69 etc 255.255.255.192, it overlaps with s0/0/0 interface, no matter it has subnet mask 252 at the end... So I put subnet 2 address 192.168.2.65 SM 192 on Branch lan, and then I could assign 192.168.2.129 and 130 SM 252 on serial interfaces between routers...

So I stop and check on the activity wizard for is it all ok, and I get an incorrect Ip address on HQ lan interfacefa0/0 (which is 192.168.2.1/26) but it says the subnet mask is ok, is this even possible? In scenario says: Assign the first valid host adress in subnet 1 to the lan interface on HQ, so isn't it 192.168.2.1, no matter what subnet mask will be??? I am so confused about this...

I tried to subnet it on /27 mask but then the ip of an fa0/0 and the subnet mask are incorrect... please help

<img src="http://www.fileden.com/files/2007/6/15/1180214/PT2.JPG" alt="PT2.JPG" />

tech-airman

Sale2506,

How many broadcast domains are there for the network?

Sale2506

Well how do you mean?
Isn't broadcast address the last address in a row? I'm not sure I understood your question well, please simplifie it for me?

jbrad95706

Sale2506 wrote: »

Well how do you mean?
Isn't broadcast address the last address in a row? I'm not sure I understood your question well, please simplifie it for me?

Broadcast domain - Wikipedia, the free encyclopedia

Sale2506

I searched on wiki before you posted it, but it only confuses me, look, just tell me how would you complete the task if The addressing for the LAN connected to the ISP router and the link between the HQ and ISP routers has already been completed. You have been given the 192.168.2.0/24 address space to complete the network design. Subnet this network to provide enough IP addresses to support 60 hosts.

So what I need is three subnets, right?
First for the HQ Lan,
they want second subnet for the Wan between HQ and Branch
And third for Branch lan.

So if I subnet the adress 192.168.2.0/26 the mask should be 255.255.255.224, and it would provide 63 adresses (if i'm right), 1st one is the subnet address - 192.168.2.0/26, the last is broadcast address - 192.168.2.63, right?

Second subnet should be 192.168.2.64/30 because it is used for serial links between Branch and HQ routers, so mask is 255.255.255.252, it gives 3 adresses, so the next subnet should be 192.168.2.68/26 ok, where am I wrong? is there some rule that I missed that says that serial links between routers should alwavs be the highest Ip adresses or?
If it is so, then why have they given me an address /24 to subnet to 3 subnets and assigned second subnet for the serial link?

Pay attention to screenshots pls, maybe they'll help more

Xenz

You're not writing it out. You need to subnet the 192.168.2.0/24 into 4 subnets.

Subnet 0
Subnet 1
Subnet 2
Subnet 3

Subnet 0 is for future use
Subnet 1 is assigned to the HQ LAN
Subnet 2 is used for the link between HQ and B1
Subnet 3 is used for the branch LAN

Are you suppose to be using VLSM (i.e /26, /30)? This seemed to be Cisco 3/4 maybe late Cisco 2 I suppose.

Your numbers are also off, /30 or 255.255.255.252 is 2 hosts. .0 - .3 where the usable addresses are .1 and .2, and so on. /26 is 64 - 2 or 62 hosts. Pay attention to what they ask or you'll have a hard time for Cisco 3/4.

*edit* Also, try to be nice around here and you'll probably be helped more. Asking us to help and then getting frustrated is not a good idea.

Sale2506

Ok, I'm sorry if I got frustrated, I'm closed in my room for 8 days, I had some operation 8 days ago and I use my time to study, but I can't get over this annoying issue and I can't go on with my study in general...

Yeah, I have to subnet 192.168.2.0/24, using VLSM, Late Cisco 2

I know that /30 is 2 hosts, so if I do it like this, where is the prob?

I assigned 1st subnet (192.168.2.0/26) to subnet 1,
I assigned 2nd subnet to link between HQ and B1 (192.168.2.64/30)
and when I try to assign third subnet (192.168.2.68/26) to the branch Lan, it says it overlaps the serial link, how is this possible if I put /30 mask on second subnet?

miller811

to complete the task you have to use the follow steps.

you have to organize the subnets from largest available address ranges to smallest available address range. That is the only way it will work properly.

you only need 4 address ranges.
if the subnets need to be in the order as described (not sure if that is the case or not) you would just break it into 4 subnets

if they do not need to be in a specific order you could have left over address space.

Sale2506

Yes, but haven't I done that?
It says, You have been given the 192.168.2.0/24 address space to complete the network design. Subnet this network to provide enough IP addresses to support 60 hosts.

There are 2 routers, which both have lan networks, and there is a serial link between, which needs 2 host ip addresses to connect, that'll be a subnet with mask /30, right?

In the taks it says:
Assign subnet 1 to the LAN attached to HQ.
· Assign subnet 2 to the WAN link between HQ and Branch.
· Assign subnet 3 to the LAN attached to Branch.
· Subnet 0 will be available for future expansion.

How do I subnet this? remembering that I have to subnet this network to provide enough IP adresses to support 60 hosts.

thenjduke

This is a little above my head as not this far into my studies yet but would you not need to 4 subnets and not over lap on the serial interfaces. I would break them up like this but I could be wrong.
Subnet 0 = 192.168.2.0/26 Subnet
Subnet 1 = 192.168.2.64/26 Subnet
Subnet 2 = 192.168.2.128/26 Subnet
Subnet 3 = 192.168.2.192/26 Subnet

Subnet 0 = 192.168.2.0
Subnet 1 = HQ to Lan 1 so Fast Ethernet Interface 0/1 would be on HQ Router 192.168.2.65
Subnet 2 = HQ to Branch so Serial Interface 0/1 would be on HQ Router 192.168.2.129
Subnet 3 = Branch to Lan 2 so Fast Ethernet Interface 0/1 would be on Branch Router 192.168.2.192

The ISP is already setup. I would create routes between these once the subnets are setup.

I really hope I have the right idea in mind here. Like I said this is beyond what I am studing at the moment as I am only studing for ICDN 1 at the moment. Please everyone let me know if I am right.

Sale2506

Ok, thanks, i'll start the activity and assign those addresses and I'll be back with answers soon

thenjduke

Sales,
I have already tried as well and getting overlaps. I really am not sure and this is a good problem.. Making me think.
Earl

Sale2506

It works 100%!!!! Thanks thenjduke, now I know where I was wrong, starting from that subnet 0, and I must say that there is a mistake in activity, but not that important, the serial interface of an ISP router should be 0/0/1, and in my PT activity file it says it's 0, but all works fine, I installed all required routes and pings everything perfectly...

Maybe you got overlaps in subnet 3, the address of an Branch interface should be 192.168.2.193, and its all correct in PT activity...

Thanks!!! Now I'm able to continue with my study, I'll ask more questions if i get more problems later

Xenz

I had just loaded up the old curriculum to see where you were going wrong.

If you had read my post you would have seen I told you to pay special attention to the subnets they wanted you to use. Subnet 0 was not used in this case. Also, there is no mention of VLSM. When they want you to use VLSM they will tell you to use the shortest mask to achieve x goal such as subnet to support 64 hosts for Subnet 0 and 1 and 12 hosts for Subnet 2 and 2 hosts for Subnet 3 and 4.

Sale2506

Ok! Thanks master Xenz

thenjduke

Yes that was what the problem was. I figure it out after I was messing around.