Basic netmask question. Please help a noobie out.

Hello,

I will be setting up a cisco site to site vpn for the first time. I
will attempt at creating two sites connecting to the main office. In
order for the site to site vpn to work among site, I will need to have
a different subnet per tunner.

My idea is the following.

1st site.


Address: 172.16.0.1
Netmask: 255.255.255.0
Wildcard: 0.0.0.255

= 254 hosts

site 2



Address: 172.16.0.2

Netmask: 255.255.255.128
Wildcard: 0.0.0.127

= 126 hosts


Address: 172.16.0.3

Netmask: 255.255.255.192 = 26
Wildcard: 0.0.0.63
Hosts/Net: 62



Am I correct to say that this setup will meet cisco requirement for
separate subnet masks? even although the ip addressing is similar?

I went from a site with 254 hosts to site 2 with 126 down to site 3
with 62 hosts. Each site has a distintive subnet mask. I would like
to keep each site ip addressing similar as its easy to remenber. Site
1 ends with .1 site two with .2 and site 3 with .3


and please pardon my newbiness. I am trying to understand it all as I
go.

thank you.

Why not just use 172.16.3.0/24 and 172.16.4.0/24 ?

In other words, site one uses addresses 172.16.3.1 through to
172.16.3.254 with a subnet mask of 255.255.255.0 . Site two uses 172.16.4.1
through 172.16.4.254 with the same subnet mask.

What addresses are you using at the main office?

"El CiD" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
> Hello,
>
> I will be setting up a cisco site to site vpn for the first time. I
> will attempt at creating two sites connecting to the main office. In
> order for the site to site vpn to work among site, I will need to have
> a different subnet per tunner.
>
> My idea is the following.
>
> 1st site.
>
>
> Address: 172.16.0.1
> Netmask: 255.255.255.0
> Wildcard: 0.0.0.255
>
> = 254 hosts
>
> site 2
>
>
>
> Address: 172.16.0.2
>
> Netmask: 255.255.255.128
> Wildcard: 0.0.0.127
>
> = 126 hosts
>
>
> Address: 172.16.0.3
>
> Netmask: 255.255.255.192 = 26
> Wildcard: 0.0.0.63
> Hosts/Net: 62
>
>
>
> Am I correct to say that this setup will meet cisco requirement for
> separate subnet masks? even although the ip addressing is similar?
>
> I went from a site with 254 hosts to site 2 with 126 down to site 3
> with 62 hosts. Each site has a distintive subnet mask. I would like
> to keep each site ip addressing similar as its easy to remenber. Site
> 1 ends with .1 site two with .2 and site 3 with .3
>
>
> and please pardon my newbiness. I am trying to understand it all as I
> go.
>
> thank you.
>
>

A while ago I contacted Cisco, and they basically suggeted to use a
similar method as Bill Grant suggested. I dont have it working 100%
yet, but thats a whole 'nother story (some network traffic doesn't
pass through VPN - such as a PC will not join a domain from a remote
site).

Hi there,

thanks for your response. I will follow it up!


btw, so far I have a single site to site working and I came across the
exact same issue as the one you are describing. I researched it for a
few days until I figured out that my ISA 2004 was blocking port 389 (
LDAP? ) I allowed the ldap to go through for the ip range of my remote
site to the internal range of my domain controller server. bingo, it
worked right after that!





On Fri, 12 Oct 2007 01:32:41 -0700, (E-Mail Removed) wrote:

>A while ago I contacted Cisco, and they basically suggeted to use a
>similar method as Bill Grant suggested. I dont have it working 100%
>yet, but thats a whole 'nother story (some network traffic doesn't
>pass through VPN - such as a PC will not join a domain from a remote
>site).

Thank you Bill. I will follow it up.


On Fri, 12 Oct 2007 14:30:20 +1000, "Bill Grant"
<not.available@online> wrote:

> Why not just use 172.16.3.0/24 and 172.16.4.0/24 ?
>
> In other words, site one uses addresses 172.16.3.1 through to
>172.16.3.254 with a subnet mask of 255.255.255.0 . Site two uses 172.16.4.1
>through 172.16.4.254 with the same subnet mask.
>
> What addresses are you using at the main office?
>
>"El CiD" <(E-Mail Removed)> wrote in message
>news:(E-Mail Removed).. .
>> Hello,
>>
>> I will be setting up a cisco site to site vpn for the first time. I
>> will attempt at creating two sites connecting to the main office. In
>> order for the site to site vpn to work among site, I will need to have
>> a different subnet per tunner.
>>
>> My idea is the following.
>>
>> 1st site.
>>
>>
>> Address: 172.16.0.1
>> Netmask: 255.255.255.0
>> Wildcard: 0.0.0.255
>>
>> = 254 hosts
>>
>> site 2
>>
>>
>>
>> Address: 172.16.0.2
>>
>> Netmask: 255.255.255.128
>> Wildcard: 0.0.0.127
>>
>> = 126 hosts
>>
>>
>> Address: 172.16.0.3
>>
>> Netmask: 255.255.255.192 = 26
>> Wildcard: 0.0.0.63
>> Hosts/Net: 62
>>
>>
>>
>> Am I correct to say that this setup will meet cisco requirement for
>> separate subnet masks? even although the ip addressing is similar?
>>
>> I went from a site with 254 hosts to site 2 with 126 down to site 3
>> with 62 hosts. Each site has a distintive subnet mask. I would like
>> to keep each site ip addressing similar as its easy to remenber. Site
>> 1 ends with .1 site two with .2 and site 3 with .3
>>
>>
>> and please pardon my newbiness. I am trying to understand it all as I
>> go.
>>
>> thank you.
>>
>>