IP Address

If an IP address is given, say 10.11.12.13, followed by /32 what is the inference here? A 'Jack & Jill' response would be appreciated.

/32 means it's a single address not a network or range of addresses.

IPv4 has 32 bits. These can be divided into network address (the first bit) and machine addresses (the second bit)

So a /32 address is unique. Its the same as a mask of 255.255.255.255
all 32 bits are used for the machine.

In a /28 address the first 28 bits define the network and all traffic for that can be routed to it, then the last 4 bits split up the traffic internally. network / machine ie 28 / 4 bits.

A /28 address would use the last 4 bits (8,2,4,1) for 14 network devices
Network: 192.168.0.0/28 11000000.10101000.00000000.0000 0000 (Class C)
Broadcast: 192.168.0.15 11000000.10101000.00000000.0000 1111
HostMin: 192.168.0.1 11000000.10101000.00000000.0000 0001
HostMax: 192.168.0.14

There's a calculator at http://jodies.de/ipcalc to play with

Thank you for your response; a lie down in darken room for an hour or so might now be necessary!

My question was posted because of this statement by TalkTalk:
Unfortunately I am unable to provide you with the fixed static IP until the line is fully live and activated as that it when it is specified; all I can advise you of at this point is the allocated range which is 212.159.161.157/32. When you line is fully installed and activated the IP will be within the previous range.

I sort of gain the impression that what is said here is total garbage and that the IP address of 212.159.161.157 has been provisionally allocated which might have to change on the day of installation and that could be anything from 212.159.160.0 to 212.159.167.255 - is my assumption correct?

In configuring a router with your logon credentials, I also can't get my head around why the recommendation is to select a dynamic IP address and not to enter the allocated IP address.

Observation and comment on the foregoing appreciated.

According to Yarwell and that calculator, there's only 1 IP address in the range 212.159.161.157/32 and that IP address is 212.159.161.157

A /32 is just a single IP address, i.e.a block of one.

In reply to a post by trolleybus:

I sort of gain the impression that what is said here is total garbage and that the IP address of 212.159.161.157 has been provisionally allocated which might have to change on the day of installation and that could be anything from 212.159.160.0 to 212.159.167.255 - is my assumption correct?

In configuring a router with your logon credentials, I also can't get my head around why the recommendation is to select a dynamic IP address and not to enter the allocated IP address.

On the latter point you don't need to worry - the PPP login process or other authentication method will dish out the correct IP to your router. This can be useful for example if you need to log into a test account which would have a different IP.

The TT email specifies a single address, 212.159.161.157/32 it's in a block allocated to Tiscali as you've spotted :-

212.159.160.0/21
ie 212.159.160.0 - 212.159.167.255

Thank you all for your responses. I think the issue can be put to bed now.

I didn't realise talktalk assigned IP's? Every time I establish a new PPP session I get a new one.

Probably a business based service

In reply to a post by MrSaffron:

Probably a business based service

Indeed it is. The service is from TalkTalK Business for £28 month + VAT to which anytime calls and CLI have been added. No FTTC available yet because of disputed cabinet position, but if, and when, available the LLU service can be upgraded by TalkTalk without issues. Not a cheap as chips service but a similar package from BT would be A LOT more. A brand new broadband and phone service with no installation costs although own router* [2830] selected for ease of inward VPN connectivity.

* Otherwise £30 charged for router plus delivery charge!