Yep, 258 is 0.0.1.2, 770 = 0.0.2.2 to give another example. Aah you added just the 2 octets. No the dotted decimal way of writing is totally different than reading it. To write out a 32-bit number, it's much easier to do it in dotted decimal way, than doing it all decimal for big numbers.
Keep writing them out in binary and you'll see what the exact number is. Oh and thanks Matt :-) -- Regards, Rick Mur CCIE2 #21946 (R&S / Service Provider) Sr. Support Engineer – IPexpert, Inc. URL: http://www.IPexpert.com On Tue, Oct 20, 2009 at 3:38 PM, Uli <[email protected]> wrote: > so if I want to get 258 is it 0.0.1.2 ? to Rick I got 510 coz I thought > it's a 0.0.255.255 since my understanding each octet equal to 1 if all bits > in that octet are up (1) sorry my mistake :) > > Thanks to Matt :) > > > On Tue, Oct 20, 2009 at 8:27 PM, Rick Mur <[email protected]> wrote: > >> The explanation from Mark is the best! Should make things clear to you. >> I'm also pretty curious to how you get to 510 :-) >> -- >> >> Regards, >> >> Rick Mur >> CCIE2 #21946 (R&S / Service Provider) >> Sr. Support Engineer – IPexpert, Inc. >> URL: http://www.IPexpert.com >> >> >> >> On Tue, Oct 20, 2009 at 5:35 AM, Matt Hill <[email protected]> wrote: >> >>> HI Uli, >>> >>> Thats not actually in decimal. It's a 32 bit number in dotted decimal >>> notation. Just like an IP address is normally dotted decimal, it can >>> also be one binary 32 bit number... >>> >>> 127.0.0.1 = 01111111.00000000.00000000.00000001 >>> = 0111111100000000000000000000001 >>> >>> Which we can make into decimal >>> >>> 2130706433 >>> >>> Try this one in your web browser and see what happens... >>> >>> 3494206055 :) >>> >>> So that's binary and decimal and dotted decimal explained... >>> >>> Same goes for OPSF areas... >>> >>> 0.0.1.1 = 00000000.00000000.00000001.00000001 >>> = 100000001 >>> = 257 >>> >>> Hope this helps. >>> >>> Cheers, >>> Matt >>> >>> CCIE #22386 >>> CCSI #31207 >>> >>> >>> >>> 2009/10/20 Uli <[email protected]>: >>> > Hi guys >>> > >>> > I just watched IPexpert VOD and in ospf section scott say that we can >>> use >>> > binary instead of decimal for OSPF area. What make me confused is how >>> can >>> > 257 equal to 0.0.1.1 ? can someone please tell me how to calculate that >>> > number coz from I know 0.0.1.1 is 510 ? >>> > >>> > regards >>> > >>> > uli >>> > >>> > _______________________________________________ >>> > For more information regarding industry leading CCIE Lab training, >>> please >>> > visit www.ipexpert.com >>> > >>> > >>> _______________________________________________ >>> For more information regarding industry leading CCIE Lab training, please >>> visit www.ipexpert.com >>> >> >> >
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