All,
IP address 172.16.0.0 with a subnet mask of 255.255.192.0 will summarise:
172.16.0.0
172.16.64.0
172.16.128.0
172.16.192.0
So therefore, the answer is the first two bits in third octet of the subnet mask
will summarise the above subnets.
or more succintly:
IP Class: B IP Address: 172.16.0.0
Mask1 Bits: 0 Subnet Mask1: 255.255.0.0
Mask2 Bits: 0 Subnet Mask2: 255.255.0.0
Mask3 Bits: 2 Subnet Mask3: 255.255.192.0
Subnets for Variable Length Subnet Masking
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Subnet Hosts Hosts Broadcast
Address From To Address
172.16.0.0 172.16.0.1 172.16.255.254 172.16.255.255
172.16.0.0 172.16.0.1 172.16.255.254 172.16.255.255
172.16.0.0 172.16.0.1 172.16.63.254 172.16.63.255
172.16.64.0 172.16.64.1 172.16.127.254 172.16.127.255
172.16.128.0 172.16.128.1 172.16.191.254 172.16.191.255
172.16.192.0 172.16.192.1 172.16.255.254 172.16.255.255
Verified straight from the horses mouth (TAC IP Subnet Calculator) at CCO
Cheers,
Jack
Norma Schutt <[EMAIL PROTECTED]> on 28/09/2000 09:10:32 AM
Please respond to Norma Schutt <[EMAIL PROTECTED]>
To: [EMAIL PROTECTED]
cc: (bcc: Jack Jessen/Sydney/CDM)
Subject: Fwd: Re: CCDA summerization question
You can summarize on the first bit but you would need two summary address
statements to cover all 4 networks:
172.16.0.0 mask 255.255.128.0 for the networks 172.16.0.0 and 172.16.64.0
172.16.128.0 mask 255.255.128.0 for the network 172.16.128.0 and 172.16.192.0
Regards,
No Shut
>It would be the first 2 bits in the 3rd octet. Go back to subnetting these
>are network numbers with the netmask of 255.255.192.0 First 2 bits make
>192. 256-192 = 64.
>64, 128, 192
>
>Scott P.
>
>"John lay" <[EMAIL PROTECTED]> wrote in message
>[EMAIL PROTECTED]">news:[EMAIL PROTECTED]...
> > Guys,
> >
> > While studying for the CCDA, I found the following question in one of the
> > exam preparation sites.
> >
> > The following IP addresses can be summaried by which bit of the 3rd octet
> > 172.16.0.0, 172.16.64.0, 172.16.128.0, 172.16.192.0 ---> 1st bit, first 2
> > bit, first 4 bit, last 6 bit
> >
> > I don't think that the following addresses could be summarized on any bit
>of
> > the 3rd octet.
> > If you have a look to the 3rd octet
> > 172.16.0.0 ---> 172.16.00000000.0
> > 172.16.64.0 ---> 172.16.01000000.0
> > 172.16.128.0---> 172.16.10000000.0
> > 172.16.192.0---> 172.16.11000000.0
> >
> > Could someone verify this with me guys ?
> > Thanks a lot
> >
> >
> >
> >
> >
> >
> > _______________________________________________________
> > Say Bye to Slow Internet!
> > http://www.home.com/xinbox/signup.html
> >
> > **NOTE: New CCNA/CCDA List has been formed. For more information go to
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> >
>
>
>**NOTE: New CCNA/CCDA List has been formed. For more information go to
>http://www.groupstudy.com/list/Associates.html
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You can summarize on the first bit but you would need two summary address
statements to cover all 4 networks:172.16.0.0 mask 255.255.128.0 for the networks 172.16.0.0 and 172.16.64.0
172.16.128.0 mask 255.255.128.0 for the network 172.16.128.0 and 172.16.192.0
Regards,
No Shut
It would be the first 2 bits in the 3rd octet. Go back to subnetting these
are network numbers with the netmask of 255.255.192.0 First 2 bits make
192. 256-192 = 64.
64, 128, 192
Scott P.
"John lay" <[EMAIL PROTECTED]> wrote in message
[EMAIL PROTECTED]" eudora="autourl">news:[EMAIL PROTECTED]...
> Guys,
>
> While studying for the CCDA, I found the following question in one of the
> exam preparation sites.
>
> The following IP addresses can be summaried by which bit of the 3rd octet
> 172.16.0.0, 172.16.64.0, 172.16.128.0, 172.16.192.0 ---> 1st bit, first 2
> bit, first 4 bit, last 6 bit
>
> I don't think that the following addresses could be summarized on any bit
of
> the 3rd octet.
> If you have a look to the 3rd octet
> 172.16.0.0 ---> 172.16.00000000.0
> 172.16.64.0 ---> 172.16.01000000.0
> 172.16.128.0---> 172.16.10000000.0
> 172.16.192.0---> 172.16.11000000.0
>
> Could someone verify this with me guys ?
> Thanks a lot
>
>
>
>
>
>
> _______________________________________________________
> Say Bye to Slow Internet!
> http://www.home.com/xinbox/signup.html
>
> **NOTE: New CCNA/CCDA List has been formed. For more information go to
> http://www.groupstudy.com/list/Associates.html
> _________________________________
> UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html
> FAQ, list archives, and subscription info: http://www.groupstudy.com
> Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
>
**NOTE: New CCNA/CCDA List has been formed. For more information go to
http://www.groupstudy.com/list/Associates.html
_________________________________
UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html
FAQ, list archives, and subscription info: http://www.groupstudy.com
Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
