class A range: 1.0.0.0 - 126.0.0.0 (127 is reserved) class B range: 128.0.0.0 - 191.255.0.0 class C range: 192.0.0.0 - 223.255.255.0
RFC 1918 defines networks and addresses 10.0.0.0 - 10.255.255.255, 172.16.0.0 - 172.31.255.25 and 192.168.0.0 - 192.168.255.255 as reserved addresses to be used as internal private addresses and not to be conected directly to the public internet. Scott E. Original Message: ----------------- From: Tom Pepper [EMAIL PROTECTED] Date: Tue, 19 Mar 2002 10:19:11 -0600 To: [EMAIL PROTECTED] Subject: Re: [IMail Forum] Proper IP Address Setup for Deny Access Thank you Scott. One more question: What is the (simplest) way to determine whether the address range is A, B, or C blocks? Thanks, Tom ----- Original Message ----- From: "R. Scott Perry" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Tuesday, March 19, 2002 8:35 AM Subject: Re: [IMail Forum] Proper IP Address Setup for Deny Access > > >Say I have a range of IP addresses from 61.149.0.0 - 61.149.255.255 that I > >want to deny access. > > > >Is it okay to specify the subnet mask as 255.255.255.0 instead of just > >inputting the 61.149.255.255 so I'll get more range of addresses blocked? > > No. > > Entering 61.149.255.255 and a subnet mask of 255.255.255.0 will block > 61.149.255.0 through 61.149.255.255. > > You want 61.149.0.0 with a netmask of 255.255.0.0 (same as 61.149.0.0/16). > > -Scott > --- > Declude: Anti-virus, Anti-spam and Anti-hijacking solutions for > IMail. http://www.declude.com > > --- > [This E-mail was scanned for viruses by Declude Virus (http://www.declude.com)] > > > Please visit http://www.ipswitch.com/support/mailing-lists.html > to be removed from this list. > > An Archive of this list is available at: > http://www.mail-archive.com/imail_forum%40list.ipswitch.com/ > > Please visit the Knowledge Base for answers to frequently asked > questions: http://www.ipswitch.com/support/IMail/ > Please visit http://www.ipswitch.com/support/mailing-lists.html to be removed from this list. An Archive of this list is available at: http://www.mail-archive.com/imail_forum%40list.ipswitch.com/ Please visit the Knowledge Base for answers to frequently asked questions: http://www.ipswitch.com/support/IMail/ -------------------------------------------------------------------- mail2web - Check your email from the web at http://mail2web.com/ . Please visit http://www.ipswitch.com/support/mailing-lists.html to be removed from this list. An Archive of this list is available at: http://www.mail-archive.com/imail_forum%40list.ipswitch.com/ Please visit the Knowledge Base for answers to frequently asked questions: http://www.ipswitch.com/support/IMail/
