Basic networking for a dummy

[1etherer]

I wrote out this long thing but the above quote is the most correct within the context of the question and it matches my experience of most CompTIA practice questions being way more complicated than the actual exams.

I'd also like to mention that plenty of enterprise networking gear can provide dhcp services, so the default gateway and the dhcp server being the same ip doesn't necessarily mean anything. You might not want to set it up that way if you can help it, but the option exists.

Gateway and dhcp being on the same ip does mean something in this question, as it means it's on the same hardware.. But yes, your right, you will get multiple dhcp servers in large ent companies

 

[The Technician]

So, someone I know who works in IT has a different theory...

"the DNS server has nothing to do with the issue. the Default gateway address is incorrect. This is the address assigned to the inside interface on your router.If your computer cannot determine the correct default gateway you will never reach the internet regardless of DNS or any other setting. Remember DNS resolves Domain names into IP addresses. It does NOT connect you to the internet. so if you look at the question the last line in the ipconfig example says "default gateway" 192.168.1.1 witch is also the address of the DHCP server. In a corporate network the Router(default gateway) and DHCP server are different pieces of hardware. so the issue is...When the DHCP server was replaced the default gateway address was misconfigured."

What do you guys think?

 

[S0ULphIRE]

It's just worded in such a silly manner. You're right, it could be that the PC has an incorrect IP set for its Default Gateway. But how did that IP get assigned? Through DHCP.
Therefore the correct answer is still C, DHCP is misconfigured. Answer D specifically says "the default gateway *router* is misconfigured", i.e. there's some settings wrong on the actual router.

 

[The Technician]

It's just worded in such a silly manner. You're right, it could be that the PC has an incorrect IP set for its Default Gateway. But how did that IP get assigned? Through DHCP.
Therefore the correct answer is still C, DHCP is misconfigured. Answer D specifically says "the default gateway *router* is misconfigured", i.e. there's some settings wrong on the actual router.

Right, so the answer to the test question is definitely C, regardless. But I'm just trying to make sure I understand all the details surrounding it, and the who-what-where-why.

 

[MidnightShadow]

So, someone I know who works in IT has a different theory...

"the DNS server has nothing to do with the issue. the Default gateway address is incorrect. This is the address assigned to the inside interface on your router.If your computer cannot determine the correct default gateway you will never reach the internet regardless of DNS or any other setting. Remember DNS resolves Domain names into IP addresses. It does NOT connect you to the internet. so if you look at the question the last line in the ipconfig example says "default gateway" 192.168.1.1 witch is also the address of the DHCP server. In a corporate network the Router(default gateway) and DHCP server are different pieces of hardware. so the issue is...When the DHCP server was replaced the default gateway address was misconfigured."

What do you guys think?

I agree with that answer. Yes, the Default Gateway could be wrong and causing the problem, but as somebody already said, that means the DHCP server is providing the incorrect information to the workstation, so it still falls back to C. You've got the understanding right, though.

 

[The Technician]

Well, I said it once, I'll say it again - I can't thank you all enough. This thread has been quite the learning experience - on of many to come, I'm certain!

Cheers!

 

[DistraughtSysop]

Remember DNS resolves Domain names into IP addresses. It does NOT connect you to the internet.

The thing is that a user who can't pull any webpages is going to report that the internet is down, regardless of whether or not they actually do have internet connectivity. The question states that "users are reporting that they are unable to browse the internet." I wouldn't take user reports at face value - all that really tells me is that they can't browse, nothing else.

Since I don't see any immediately obvious problems with that ipconfig, it's possible that they do have internet and they just aren't able to get to websites. When this happens, it's often because of a DNS issue. I would have to troubleshoot it further to be sure, but it happens often enough in real world scenarios - that's why people are talking about DNS.

so if you look at the question the last line in the ipconfig example says "default gateway" 192.168.1.1 witch is also the address of the DHCP server. In a corporate network the Router(default gateway) and DHCP server are different pieces of hardware.

They don't necessarily have to be separate pieces of hardware. Just about any Cisco router, switch, or ASA can be configured to provide dhcp services. You generally don't want to do that if you can help it, but plenty of SMBs will cheap out on IT equipment and use the same box for multiple services. A lot of smaller businesses will straight up use home routers because they're cheap. If you see the same device as both the gateway and dhcp server in a business network then it looks kind of weird and isn't a good practice, but it's not an impossibility.

Answer C is really just the "best guess" answer. A and B are very false, and D is only true if all the users online are using one gateway and the users that are offline are using another gateway. C is possible, but not definitive given the available information.