Local Trafic address list

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MobileAllOver

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I managed to get the local IP address from server public-route-server.is.co.za

(telnet public-route-server.is.co.za ; sh ip bgp)

There are routes without a subnet mask - ie 195.25.0.0
I assume that network addresses that end with 0.0 should be 0.0/16
and address that end with .0 should be .0/24

Any feedback?

I'm configuring my MikroTik router with 2x ADSL connections; one International (SAOL) ; other national (GamCo)
 
No problem, but is my assumption on the 0.0 => 0.0/16 and .0 => .0/24 correct? If you execute the sh ip bgp function it returns a list with all addresses - some with and other without subnet masks...
 
Aah.. now comes the fun Binary part :)
Its actually a bitmap that determans the bitmask on a .0.0 subnet

Warning: BINARY
if the address starts in 0 (ie: addresses from 0 up to 127.255.255.255) its a /8
if the address starts in 10 (ie: 128.0.0.0 - 191.255.255.255) its a /16
if the address tarts in 110 (ie: 192.0.0.0 - 223.255.255.255 ) its a /24

Any address above 224.0.0.0 is a Multicast address.. and wont really be applicable here.

Nice reference here.
(http://www.eventhelix.com/RealtimeMantra/Networking/ip_routing.htm)
 
daffy said:
Aah.. now comes the fun Binary part :)
Its actually a bitmap that determans the bitmask on a .0.0 subnet

Warning: BINARY
if the address starts in 0 (ie: addresses from 0 up to 127.255.255.255) its a /8
if the address starts in 10 (ie: 128.0.0.0 - 191.255.255.255) its a /16
if the address tarts in 110 (ie: 192.0.0.0 - 223.255.255.255 ) its a /24

Any address above 224.0.0.0 is a Multicast address.. and wont really be applicable here.

Nice reference here.
(http://www.eventhelix.com/RealtimeMantra/Networking/ip_routing.htm)
Click to expand...

True, but in real life we use Subnetting to divide to existing ip ranges into smaller parts. Divide logical / physical networks...

Look at the following at is an extract from the public-route server

* 152.112.0.0 168.209.255.8 0 3741 5713 2018 i
* 152.158.80.0/22 168.209.255.8 0 3741 2686 i
* 155.159.0.0 168.209.255.8 0 3741 i
* 155.232.0.0 168.209.255.8 0 3741 5713 2018 i
* 155.234.0.0 168.209.255.8 0 3741 i
* 155.235.0.0 168.209.255.8 0 3741 i
* 155.236.107.0/24 168.209.255.8 0 3741 i
* 155.236.110.0/23 168.209.255.8 0 3741 i

the /23 /23 and /24 subnets are fine - I do understand the subnetting...
Then the ones without any slashes... These examples are on a class B subnet, meaning 255.255.0.0 subnet mask (/16). My initial question was if we can assume that all of them are /16 seeing that it's a class B (0.0)

But we do have other entries that specifically specifies / 16
*> 196.9.0.0/16 168.209.255.8 0 3741 2905 i
*

Hence, why specify the /16 only sometimes?

Think I do have the answer... Looking at the above example we see that it belongs to a class C network (/24), so the mask was specified with /16 because it deviates from the standards.

Thanks for all the input - Im quite ure this is how it works...

Any change that these entries will change?? I need to upload in to my Router - don't want to schedule a weekly update
 
Okay.. you've mis-understood the usage of the term Class A, Class B and Class C.

In the definitions I gave,
if the address starts in 0 (ie: addresses from 0 up to 127.255.255.255) its a Class A
if the address starts in 10 (ie: 128.0.0.0 - 191.255.255.255) its a Class B
if the address tarts in 110 (ie: 192.0.0.0 - 223.255.255.255 ) its a Class C

(Note: a /8 is NOT a Class A if it isn't in the 0 - 127.255.255.255 range, its just a /8 subnet)
These Class A/B/C assumptions are made by the routers too.
So if a Class and netmask dont match up, then the netmask is specified.

Thus, if you find a route without a netmask, then use the "standard" netmask for that Class.

The local subnets dont change too often.. but there are a few nasties that you should look out for.
IS has implemented its fixed IP ADSL solution by assigning a /29 to subscribers via BGP. So if you look through that list, you'll see hundreds of /29's. Try and agregate these to make the routers life a bit easier :)
 
Thanks - I perfectly understand class A/B/C networks... My router is already up & running with all correct local subnets.

Can these local IP address ranges change or it is fairly static?
 
They can change. AfriNIC is allocating new IP ranges to South African ISP's all the time..
 
MobileAllOver

They hardly change.

remember to add 196.209.0.0/16 its not listed and that the IS user range.
 
How can I pipe the Telnet output to a file on Windows? The normal <, > and >> pipe symbols don't seem to work. I'd like to automate the IP range retrieval...

Edit: I found a tool called Telnet Scripting Tool that works just fine... :)
 
Last edited:
I use putty as terminal client with logging option. then import into excel, sort, delete all formatting and create script
 
oober said:
MobileAllOver

They hardly change.

remember to add 196.209.0.0/16 its not listed and that the IS user range.
Click to expand...


Are you sure it is 196.29.0.0/16. I had some issues with news.is.co.za - the traffic still went through my international line.

I did change it to 168.29.0.0/16 - Everything works! I have send my routing scripts to several people - hope you all read this
 
Not sure, but neither of them have got the ranges
196.209.0.0 (Other IS ADSL users)
168.209.x.x (like news.is.co.za 168.209.98.66)
 
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