Troubleshooting a network

oli356 · 20 Apr 2012 at 23:11

Hey all

Might as well see if I can get any help here. Doing a CCNA troubleshooting excercise on packet tracer.

So above is what I have.

The wireless network can ping the other 2 network hosts.
The other 2 networks can ping each other but not the laptops. They can't ping 192.168.4.1 but can ping 192.168.3.1.

This is where I get confused, why can the laptop ping the deskstops but not the other way around.

ISR config internet settings (static):
Default gateway: 192.168.3.1
IP: 192.168.3.2

LAN Settings:
192.168.4.1

Router2 settings (centre router):
FastEthernet: IP 192.168.1.1
Ethernet 1/0: IP 192.168.2.1
Ethernet 1/0: IP 192.168.3.1

What I don't quite get exactly is the internet and LAN settings on the ISR and I assume that this is causing the problem... :S

Any help would be much appreciated

oli356 · 21 Apr 2012 at 00:06

The requests are timing out when pinging from a desktop to a laptop. Fine the other way round. Which as you said, I don't understand..

Hmm, all the subnet masks for the desktops/laptops are 255.255.255.0 (as I would expect from Cisco, especially as at this stage subnetting hasn't been mentioned)

The only other thing I noticed is in router 2
Routing, static:
192.168.4.0/24 via 192.168.3.0

RIP routing
192.168.1.0
192.168.2.0
192.168.3.0

Which means nothing to me!

Thanks

oli356 · 21 Apr 2012 at 05:18

From:
IP Address......................: 192.168.1.2
Subnet Mask.....................: 255.255.255.0
Default Gateway.................: 192.168.1.1

Code:

PC>tracert 192.168.4.101

Tracing route to 192.168.4.101 over a maximum of 30 hops: 

  1   7 ms      5 ms      9 ms      192.168.1.1
  2   *         *         *         Request timed out.
  3   *         *         *         Request timed out.
  4   *         *         *         Request timed out.
  5   *         *         *         Request timed out.
  6   *         *         *         Request timed out.
  7   *         *         *         Request timed out.
  8   *         *         *         Request timed out.

Wasn't going anywhere.

From:
IP Address......................: 192.168.2.2
Subnet Mask.....................: 255.255.255.0
Default Gateway.................: 192.168.2.1

Code:

Tracing route to 192.169.4.101 over a maximum of 30 hops: 

  1   17 ms     10 ms     9 ms      192.168.2.1
  2   4 ms      *         10 ms     192.168.2.1
  3   *         6 ms      *         Request timed out.
  4   9 ms      *         10 ms     192.168.2.1
  5   *         8 ms      *         Request timed out.
  6   7 ms      *         8 ms      192.168.2.1
  7   *         7 ms      *         Request timed out.
  8   4 ms      *         9 ms      192.168.2.1
  9   *         6 ms      *         Request timed out.
  10   7 ms      *         8 ms      192.168.2.1
  11   *         8 ms      *         Request timed out.
  12   9 ms      *         6 ms      192.168.2.1
  13   *         8 ms      *         Request timed out.
  14   7 ms      *         7 ms      192.168.2.1
  15   *         9 ms      *         Request timed out.
...
  30   9 ms      *         8 ms      192.168.2.1
Trace complete.

Noe the other way around:
IP Address......................: 192.168.4.101
Subnet Mask.....................: 255.255.255.0
Default Gateway.................: 192.168.4.1

Code:

Tracing route to 192.168.2.2 over a maximum of 30 hops: 

  1   16 ms     11 ms     18 ms     192.168.4.1
  2   *         *         *         Request timed out.
  3   19 ms     12 ms     14 ms     192.168.2.2

Trace complete.

oli356 · 21 Apr 2012 at 11:48

All the router settings were configured when I started so not changed anything. Think the best way for this is to show you images unless you have packet tracer installed!
http://imgur.com/a/uAZnS

So your saying add 192.168.4.0 to the RIP Routing table and delete the current static routes and make it 192.168.4.0/24 via 192.168.3.2?

Thanks,

oli356 · 21 Apr 2012 at 12:41

Changed the route to 4.0 via 3.2, no difference.

I just can't get why the laptops can ping the desktops but not the other way, as Skid mentioned its a send and receive.

From a desktops I can ping the default gateway of the ISR (3.1) but thats it =/

oli356 · 21 Apr 2012 at 13:12

SoundsGood said:
Upload the .pkt

http://dl.dropbox.com/u/67409120/OIA_Assign1.pkt.pkt

oli356 · 21 Apr 2012 at 14:02

ots3go said:
If you can ping one way then you've confirmed traffic is flowing both ways, so routing is probably not the issue else the return packet would be lost and ping would fail.

Are there any ACL's enabled?

Got a slight idea of what ACL is, looked around and no.

Skidilliplop said:
2nd tracert can be ignored as you've traced to 192.169. not 192.168.

Won't work with the correct IP anyway

This is been given to people who will be half way to getting a CCENT, thought it would be really easy. Doesn't help that I've never even seen things such as:

en
conf t
network 192.168.4.0

Though as it's never been mentioned I can't see Cisco making us need to know.

oli356 · 21 Apr 2012 at 14:13

MilanoChris said:
You need to know RIP for CCENT.

I'll look at the exercise later, bit busy atm.

Will probably come in later then, not sure how it's done normally but at college we use the cisco academy. So I'm doing working at a small-to-medium business or ISP. Done Discovery 1 (given this then), working through discovery 2, when I've completed that I can do the exam for the CCENT.
Only done a chapter 1,2,3 of Discovery 2 and they wern't really technical, on 4 now which is subnetting and there's 9 chapters.

Thanks

Skidilliplop said:
You will need to know. You can't do ANYTHING on ciscos without en + conf t.

and virtually every dynamic routing protocol needs network x.x.x.x in some form.

Configuring network devices is my next chapter, talks about the IOS CLI etc

oli356 · 21 Apr 2012 at 14:22

MilanoChris said:
The academy is a very slow way of learning, designed for college students learning for CCNA in semester. You can teach it to yourself in a few weeks of hard study if you have a networking background or understand the fundamentals.

Get hold of Jeremy's CCNA (ICND 1 and ICND 2) nuggets, much faster and he explains everything so much better.

ICDN 1 is CCENT.

Yeah, it is slow! My teacher was telling me she did it in 2 weeks. We've been doing this since September, most of the class hasn't even done Discovery 1. I'm trying to get through Discovery 2 before June, should be done though I have lots of other stuff to do!
Figured I will just be doing it all outside of college so if I can do ICDN1 in college then I just have to do ICDN2 outside (or however it works out)

Will take a look at that, I've found the Cisco academy content to be decent. Though a lot of it seems common sense: speaking politely etc.

oli356 · 21 Apr 2012 at 17:14

Thanks Chief Wiggum. Read that a few times and think I've got my head around it... Though not sure what the heck I'm going to write for "run appropiate tests and identify and list problems you discover. Correct them and test the network again, produce a report explaining everything.." Because from what we've done at this low level if x can ping y, y should be able to ping x. Which isn't possible on here then.

As mentioned it seems like the whole configuring devices and the CLI, IOS etc is after I pass this subnetting chapter so will learn then and try and do as much of that. Might as well ask my teacher about the 'problem' as well, see what he says!

Now for this! http://i.imgur.com/xyYpS.jpg Which at first looks more annoying then the troubleshooting

Thanks again for all your help =)

oli356 · 21 Apr 2012 at 17:40

That makes more sense even on the wine

thanks, clears things up more so.

oli356 · 28 Apr 2012 at 17:26

MilanoChris said:
en
conf t
network 192.168.4.0

I now know what that means

Just gone through the configuring a router and switch section on Cisco acadamy... it was LONG, double the length at least of the previous longest chapter.

Lots of things I understand and some things I don't.... going to have reading through it again

oli356 · 29 Apr 2012 at 11:09

Yeah, I still need to go through the acadamy for college. Ideally wanting to finish Discovery 2 but as mentioned that chapter took me hours to read..

Got CBT nuggets, good stuff

Explains everything well and its not boring.

So trying to watch the videos which correspond to whatever I'm doing on the acadamy. But also read through the chapters because might be things I need to know what isn't mentioned in the videos.

oli356 · 4 May 2012 at 14:32

So I'm doing more P tracer exercises and feeling like a idiot. I've gone through my academy tests about setting up routers and switches and routing protocols and I can't do this -.-

Anyway. 3 floors in a building, a switch per floor and 1 floor has 2. 4 laptops need to connect as well. 22 computers will be connected per switch.
I need to setup the network, give laptop dynamic IPs (done) and static ones to the desktops (done). They can all ping each other fine. The private network is 192.168.1.0

Problem:
ISP has provided the IP address of 210.155.221.16 /24. So I go into the GUI of the wireless router (WRT300N) and am failing on setting up the static IP for the WAN interface. Just need to be able to ping it.

Internet IP: 210.155.221.16 (as assigned by ISP)
Subnet: 255.255.255.0
Default Gateway: 210.155.221.x? I would've thought the IP address would be the same as the gateway for a router.. no?

I feel embarrassed

http://dl.dropbox.com/u/67409120/design.pkt

oli356 · 7 May 2012 at 22:56

Oh right! Yes I had put the ISP router there but sort of just left it! Makes perfect sense about the interface being down. Simple solution then

Will do it when I'm back at my desk.

Thanks a lot once again =)