IP Ranges?

mooonpie

Does anyone know the IP ranges for the networks of the student villages in UL?

kaimera

Why?

rmacm

moonpie9588 wrote: »

Does anyone know the IP ranges for the networks of the student villages in UL?

The addresses are assigned by DHCP. ipconfig /all from the command line will give you the information you need to figure out the address range. As kaimera said what do you intend to do with this info because if it involves stuff like port scanning (or other gob****ery) you risk being booted off the network by ITD.

Cheers
Rory

mooonpie

to be honest it was just idle curiosity. i just found out about CIDR and how IP addresses and Subnet Masks are linked so i was just wondering what differrent masks there are on each village, if indeed they were different at all.
as i said t'was just idle curiosity.

rmacm

Ah right cool well as I said if you type ipconfig /all form the command line in Windows it'll show up the IP Address and Netmask that your laptop/desktop has been assigned....assuming you live in one of the villages. You should be able to calculate the address range in use given the information you get from the output from this command.

Cheers
Rory

mooonpie

ipconfig will only give the info for the network im directly connected to (kilmurry). i have ip's from plassey and from dromroe from last year and neither fits into the ip range that i calculated for kilmurry.

so either ITD changed the networks around over the summer, or each village is on a different subnet mask and hence a different ip range. or maybe both!

cheers anyway!

rmacm

True you'll be able to calculate the address range for Kilmurry not the others.....what's your current IP and netmask? It's probably something like 10.x.x.x and the netmask is should be something along the lines of 255.x.x.x

Give us the ones from Plassey and Drumroe and I'll be able to figure it out.

Cheers
Rory

mooonpie

i only have the ip addresses from plassey and dromroe, no net masks. otherwise id be able to work out the ranges myself.

anyhu, Plassey is 10.200.0.99 and Dromroe is 10.200.4.226

rmacm

Netmask is probably 255.255.255.0 then for all 3 of them...e.g. first network available would be 10.0.0.0 and the next one being 10.0.1.0 and so on.

mooonpie

well kilmurry is definitely 255.255.248.0, which is why i wasnt assuming any other values

Peteee

Plassey is 10.200.0.99 and Dromroe is 10.200.4.226

rmacm wrote: »

Netmask is probably 255.255.255.0

I'd say moonpie is correct, 255.255.255.0 doesn't seem right at all.

The network is probably a /21 network, so the network is assigning 3 bits of the second last octet as hosts, hence the 10.200.0.99 -> 10.200.4.226

Of course it's been a while since I did this so I might be completely wrong. A /21 address block for each village allows ~2048 hosts, which seems a tad excessive.

mooonpie

This means Kilmurry is fairly different to Plassey and Dromroe, then again is there any reason they should be similar? The range I calculated for Kilmurry with my IP address (10.100.128.x) and Subnet Mask (255.255.248.0) is:
10.100.128.0 --> 10.100.135.255
Am I right in saying this is a /21?

Also, I suppose ITD could have changed the IP ranges over the summer to stop "port scanning (or other gob****ery)" that rmacm was referring to in an earlier post?

As i said earlier I'm new to the "in's and out's" of CIDR, IP's and Net Masks

Peteee

Hmm, I've thought about this a bit more, and I'm not sure that my original reasoning is correct.

The 3 bits of borowed addressing would allow for a 'jump of 7' (Or 'jumping 8 numbers' to be on the next subnet, 2 ^ 3 == 8) numbers in the third octet (As shown in moonpies post above, 128 to 135) not just the 4 that I said in my previous post. Damn bits and decimals are hurting my brain.

Of course, this assumes that Kilmurray and Dromroe etc are all on different subnets.

If they arent, then the /21 addressing scheme is a decent scheme (There is less then 2048 machines dotted around all the different villages, a reasonable estimate I'd say)

Subnet Mask (255.255.248.0) is:
10.100.128.0 --> 10.100.135.255
Am I right in saying this is a /21?

If the subnet mask is 255.255.248.0 then yes, its a /21 address. Its a /21 because 21 of the left most bits are being used as the network identifier, and the remaining 11 being used as a host identifier (2 ^ 11 == 2048) Though you probably know all this already.

Are you doing Comp Sys or IT/IS? The big hands of Mr. O'Shea may help guide you!

rmacm

Peteee wrote: »

I'd say moonpie is correct, 255.255.255.0 doesn't seem right at all.

The network is probably a /21 network, so the network is assigning 3 bits of the second last octet as hosts, hence the 10.200.0.99 -> 10.200.4.226

Of course it's been a while since I did this so I might be completely wrong. A /21 address block for each village allows ~2048 hosts, which seems a tad excessive.

Yep I was a bit sleepy last night when I was thinking about it....the /21 makes far more sense....2048 hosts per subnet I wouldn't say it's excessive just allowing for expansion. Each of the villages are probably on a different subnet because they're connected to the college backbone network through a router so that would provide inter subnet routing.

e.g. Plassey could be using the 10.0.8.0 range, Kilmurry the 10.0.16.0 range and Drumroe 10.0.24.0 range and so on jumping in 8s for the other villages.

Cheers
Rory