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> -----Original Message----- > From: Stephen Angell [mailto:stephen dot angell at gbsd dot org] > Sent: Monday, February 23, 2004 3:01 PM > To: Brandon Holland > Subject: Re: [m0n0wall] rules rule me > > "Brandon Holland" <brandon at cookssaw dot com> writes: > > > >Opening a port in your firewall won't magically cause GRC to see that > >the port is open. > > > >A PASS rule bypasses the firewall. If there is a place for the packet > >to go once it passes the firewall rule (to say your listening SMTP > >server on port 25) then GRC will see the mail server and tell you the > >port is open. > > > >If however you have a rule to PASS with nothing to pass to (if you > >haven't set NAT on the port or m0n0wall doesn't have the port open) > >it'll hit the top stack and return a reset packet, telling GRC it's > >"closed". > > Sure enough, I started Netmeeting and GRC now says it open. Thanks for the > education. I am still unable to get it, Netmeeting, working but at least I > know it is not the rule that is causing me a problem. > > > > > >This is called Classless Interdomain Routing (CIDR) I believe it is > >anyway, I'm not looking it up and I've heen out of cisco for a while... > > > >At any rate, to keep things brief: 32 is a single host, 24 is > >255.255.255.0, 16 is 255.255.0.0, 8 is 255.0.0.0, 0 is the world > > > >The /number corresponds with the number of bits you want to use as the > >network number. (Leaving what's left as the host number) > > > >For a 255.255.255.0 mask the first three octets are network numbers, the > >last is host. 255 is represented by 8 "on" bits and 8*3 equals 24 so > >hence the /24 for the typical class C address. > > > OK, gotta read up on this one. One question: Is this the mechanism to > specify a range of IPs to apply a rule to instead of creating a rule for > each IP? A simple yes or now would suffice. If yes, I can then go and > learn CIDR to figure it out. If no, I guess I have to specify a rule for > each IP. > > Thanks for your reply Brandon ... and your patience with a newbie such as > me. > No, it's the replacement for the "old fashioned" subnetting (allows for more thorough use of the ipv4 space - since it's quickly being used up) What you're talking about will happen when the new ipfilter comes out (whenever that may be) It's just another way of specifying either a host or a network (subnet) Brandon > > > > >Brandon > > > > Stephen > |