[Supersaddler]

hello

I would be gratefull of a little bit of help

I'm doin subnetting and have an exam tomorow - i am doing a test exam and got half way though and have got stuck on something which is most probably really easy.

"The Boaz-GAD network address is: 192.168.1.0/24. The WAN interface of GAD is assigned the lowest usable address in the subnetwork. Identify and use the second lowest usable WAN address for the S0/0 interface of the Boaz router"

this is the part i am stuck on, every ip address i try says that it is wrong - does any1 know the 2nd lowest usable WAN address for the above and why?

any help would be great

thanks

 

[TheWiz]

HI. Is that a copy of the entire question? Was there a diagram as well? Is there any other info given in the question or even the section as some exam questions relate to a network diagram given at the start of a section.

The only subnetwork given here is a /24 which is rather large for a WAN connection in most cases. The lowest usable address in the range given is 192.168.1.1 mask 255.255.255.0 and the second lowest usable address is 192.168.1.2 mask 255.255.255.0.

What addresses have you tried already?

 

[Supersaddler]

Hi, thanks for your reply, I've included the rest of the question below

the answear you have given is the first answear i gave but is still telling me ip adress incorrect.

I have given the machines the correct IP address's but the ip addresses coming in on both the serial and ethernet port i just can't get

Will try and get a diagram but basicly is like this

GAD (router) ------------------ Boaz(router)---------------SWA(switch) - then 2 machines

Thanks again for your reply




The Boaz-GAD network address is: 192.168.1.0/24. The WAN interface of GAD is assigned the lowest usable address in the subnetwork. Identify and use the second lowest usable WAN address for the S0/0 interface of the Boaz router.

The local LAN of the new branch office is assigned an IP network address range of: 130.10.0.0/24. This LAN must be subnetted. Each subnet of the Internetwork needs to accommodate 32 host addresses. (Use the smallest subnet mask available that still provides for the 32 hosts per subnet.) Determine the first 10 subnets available. Use the fourth usable subnet for the LAN connected to SWA (LAN subnet). Do NOT count subnet zero as the first subnet.

The Ethernet interface connected to Boaz connecting to SWA is assigned the highest usable address within the LAN subnet.

For security reasons, the IP addresses of the Hosts on the LAN subnet are split in two groups. The production workstations will be assigned the lower half of the IP addresses from the fourth subnet. The network devices and management stations will be assigned the upper half of the IP addresses from the fourth subnet. The decision bit for determining upper and lower host device IP addresses is the bit directly after the last subnet bit. Example: if the subnet mask is 240, the first 4 bits indicate the subnet, the 5th bit will determine if the host falls within the lower range or upper range of hosts (where 0 indicates lower range and 1 indicates upper range).

PC0 simulates a production host. The IP address of this host is the first IP address within the lower range of the IP addresses. PC1 simulates a management host. The IP address of this host is the first IP address within the upper range of IP addresses.

 

[TheWiz]

Hi. I have looked at this and am as confused as you are - perhaps more. I have been doing networking for 15 years and I think the question writer is pretty ordinary.

First, the adresses I gave are correct and I cannot see how there are any other answers.
Second, the direction to divide the LAN subnet into smaller subnets accommodating "32 hosts" is interesting. If you apply a mask of 255.255.255.224 (or /27) then you are left with 32 addresses in that subnet - however - only 30 of these are available for "hosts" as the other 2 are broadcast addresses. This means that the smallest subnet capable of supporting 32 "hosts" is a /26 subnet providing 64 addresses with 62 usable host addresses.
Thirdly, the question advises that the LAN address is 130.10.0.0 /24 and must be divided. a /24 subnet can only be divided into four /26 subnets as follows;

130.10.0.0 /26
130.10.0.64 /26
130.10.0.128 /26
130.10.0.192 /26

The question advises you cannot use the zero subnet and have to use the 4th usable subnet. This is impossible if you discount the zero subnet as there are only four subnets.

Lastly, the PC's addresses will be the following IF you use the fourth subnet listed above;
production host - 130.10.0.193 mask 255.255.255.192
management host - 130.10.0.224 mask 255.255.255.192
Ethernet interface of Boaz for LAN switch is 130.10.0.254 mask 255.255.255.192


I hope this has been more helpful to you than the question itself.