Question

havenladhavenlad Posts: 27Member ■□□□□□□□□□
Found this question in a book but I don't get it

This answer seems to me to be wrong. What do others think?

There are 3 routers connected via serial links. The routers have 27 hosts, 17 hosts and the one we are looking at has 13 hosts. The question is which address should the fast ethernet address have on the router with 13 hosts. I think the number of hosts on each subnet is irrelevant though.

We are subnetting on 192.168.1.0 with a mask of 255.255.255.224

That's ok so far, but is says we are using RIP1. How would that work with a subnet of 224. Surely it would not see the subnetted bits if using RIP1?

The answer I find even more strange. Options are:

xx.xx.xx.64
xx.xx.xx.192
xx.xx.xx.190
xx.xx.xx.31
xx.xx.xx.127

I went for 64 as 192 seemed less correct.

The answer was 190, because all the others are either broadcasts or subnets. But if we are looking for a fast ethernet port from a router with a number of hosts, it would be subnet address surely no?

Comments

  • MonkerzMonkerz Posts: 842Member
    What book are you getting this question from? I fear there may be some information lost in your post.
  • havenladhavenlad Posts: 27Member ■□□□□□□□□□
    It's a locally produced book ie just questions written by some lecturer. Virtually copied it but I agree it does seem to miss bits out. The main point is RIP1 doesn't recognise subnetting and the fact it asks for a host address. i think I'll scrap the question to be honest
  • boredgameladboredgamelad Posts: 365Member ■■■■□□□□□□
    havenlad wrote: »
    The answer was 190, because all the others are either broadcasts or subnets. But if we are looking for a fast ethernet port from a router with a number of hosts, it would be subnet address surely no?

    You don't assign a subnet ID to an interface. The IP address you use for interfaces has to be one of the valid host IPs in a given range.

    The fact that it's asking about RIP v1 is a bit weird though.
  • hawandaeihawandaei Posts: 5Member ■□□□□□□□□□
    sorry your question is incomplete
  • havenladhavenlad Posts: 27Member ■□□□□□□□□□
    The full question:

    A network is using subnets of 192.168.1.0 with a mask of 255.255.255.224. RipV1 is in use. Which address should be used for an FA0/0

    192.168.1.31
    192.168.1.190
    192.168.1.192
    192.168.1.64
    192.168.1.127

    That's the full text of the question

    The answer is 190, with the explanation that it is the only one that isn't a subnet address or broadcast address, but I read the question as it is looking for the interface of the router, therefore should be a default gateway.

    As I'm taking a fresh look at this it is making a little more sense - I can now see that it can't be a broadcast (31 and 127) and can't be a subnet network address (64 and 192) so it must be 190. But how would it pick up a .224 subnet using RIPV1?
  • MonkerzMonkerz Posts: 842Member
    I think you are looking too deep into the question. This is a subnetting question, what the router uses to advertise is irrelevant. Whatever/whomever created this question intended to throw the reader off by adding a "squirrel"' :)
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