[Shorewall-users] Slight problem with 8 Ip's addresses, using
shorewall as router (dhcp ills as well)
Sat, 27 Apr 2002 10:02:57 +1000
> Hi All,
> Well, I've had a stab at this, but haven't managed to get it going just
> I now have a batch of 8 IP's on a /29 subnet.
> My ISP has said, make your router 188.8.131.52
> You cant use 184.108.40.206 or 220.127.116.11
> 18.104.22.168 - 253 are available to you.
8- or 4-length subnets are a bit of a waste, aren't they?
> My linux box has booted up, and assigned its self on ppp0 to have
> 22.214.171.124, P-t-P of 126.96.36.199 and netmask of 255.255.255.255.
That netmask is for the PPP link itself.
> I have setup my dhcpd to have:
> A network address of 188.8.131.52, netmask of 255.255.255.255
> An address range of 184.108.40.206 - 220.127.116.11
> But it moans that address range 18.104.22.168 to 22.214.171.124 is not
> on net 126.96.36.199/255.255.255.0
That is not going to work. Your subnet is 188.8.131.52/29, which is equivalent
to 184.108.40.206/255.255.255.248. The address range you should give it is
220.127.116.11-18.104.22.168. I don't know why your ISP told you not to use .249 -
they don't seem to be using it for the PPP link, so you should have full use of
> Have also tried with netmask of 255.255.255.248
That should work fine. Try it with a base address of 22.214.171.124 if it's not
> My eth0 interface is setup as per the ppp0 interface, although it has
> a broadcast address of 126.96.36.199 (?) and a netmask of
The netmask is right, but the broadcast is definitely not. Broadcast on that
LAN should be 188.8.131.52.
> If i turn off dhcp my other pcs can ping the firewall router and use
> the web. So half the hurdle is the dhcp ide of it I think.
Most of it. :-) I think conflicting netmasks might be part of the issue, too.
The only netmask you should see on your LAN is 255.255.255.248 - 255.255.255.255
is for your PPP link only.
P.S. If anyone's interested in some basic reference material on netmasks and
the like, see my web page under the heading "Unix Networking Basics".