Simple netmask question

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.

On Fri, 12 Oct 2007 02:23:47 GMT, El CiD wrote:

> 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.

You're addressing doesn't make much sense! .1, .2 and .3 aren't valid
network addresses for those netmasks.

172.16.0.1 mask 255.255.255.0 is an IP address in the 172.16.0.0 /24
network (172.16.0.0 to 172.16.0.255)

172.16.0.2 mask 255.255.255.128 is a host in the 172.16.0.0 /25 network
(172.16.0.0 to 172.16.0.127)

172.16.0.3 mask 255.255.255.192 is a host in the 172.16.0.0 /26 network
(172.16.0.0 to 172.16.0.63).

As you can see, these all have overlapping addresses and so would be
difficult to use in a VPN situation without employing NAT.

Why not keep it simple and use ..

Site 1 172.16.1.0 /24
Site 2 172.16.2.0 /24
Site 3 172.16.3.0 /24

Chris.