Dennis, you might want to change the Subject Line. This is not an OSPF question. Wildcard mask, in a nutshell. 1) write everything relevant in binary. 2) In the case of a 0 in the mask, it is safe to say that this means an exact match in any octet. So, in your case, the 10 in the first octet with a 0 in the corresponding octet of the wildcard mask, means that the only matches will be for those hosts with a 10 in the first octet. 3) With anything other than a zero in any wildcard mask octet, write it out in binary until you understand what is going on. Even then, you should write it out in binary, just to be sure. In your example, the last octet of the host address range is 192, as in 10.11.216.192 Writing it in binary, we get 1100 0000 = 192 decimal Writing the mask in binary we get 0011 1111 = 63 Line up the numbers: 1100 0000 = network side/host side 0011 1111 = wildcard mask every place where there is a zero in the mask, there MUST be an exact match in the network side ( or host side, if you want to look at it that way. So, every packet with a source address of 10.11.216.binary = 11xx xxxx will be permitted the ones in the mask mean that it doesn't matter whether it matches or not. 1100 0010 matches 1111 0000 matches 1101 1001 matches 0111 0011 does NOT match ( see why? ) are you beginning to get the idea? So now it's your turn. You tell us what the command access-list 50 permit 10.11.216.192 0.0.0.63 does. Chuck -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]] On Behalf Of Dennis Ighomereho Sent: Sunday, June 11, 2000 10:06 AM To: [EMAIL PROTECTED] Subject: ospf hi, could someone explain this to me.on 3500 series switch.There is a statement access-list statement saying access-list 50 permit 10.11.216.192 0.0.0.63 could you tell me from what ip range does this allow access or how is this worked out. cheers ________________________________________________________________________ Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com ___________________________________ UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html FAQ, list archives, and subscription info: http://www.groupstudy.com Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] ___________________________________ UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html FAQ, list archives, and subscription info: http://www.groupstudy.com Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
