Well, lets say that you have an IP address on your loopback, and it is a /32 or /29 or whatever really. You could use that IP address or part of that subnet for a NAT pool. When the NAT clients translate to that real ip address, it appears to outside hosts as if they are coming from that IP. If you don't advertise the loopback IP or subnet (rid), then your network will not know how to get back to that IP address when return traffic comes in for the NAT clients. That is one example of when you would have to advertise the loopback, and in turn the rid. Otherwise there is no real requirement to advertise them that I know of.
-----Original Message----- From: cybertek [mailto:[EMAIL PROTECTED]] Sent: Tuesday, January 15, 2002 7:02 PM To: [EMAIL PROTECTED] Subject: Re: To advertise OSPF RIDs or not ? [7:32042] Thanks for your help, I was just going through a lab and this question came to my mind. Can you explain why when using NAT would you need to advertise router IDs. I am really dense today. Thanks ""Lupi, Guy"" wrote in message [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... > Well, that depends. If you use a loopback as the router id, and part of > that loopback subnet is used for other things also, such as NAT, then you > definitely want to advertise it out, since the NAT would never work if you > didn't. If not, then you don't have to. Why do you ask, is this for a > particular application? > > ~-----Original Message----- > ~From: cybertek [mailto:[EMAIL PROTECTED]] > ~Sent: Tuesday, January 15, 2002 2:15 PM > ~To: [EMAIL PROTECTED] > ~Subject: To advertise OSPF RIDs or not ? [7:32042] > ~ > ~ > ~I am trying to understand if there would ever be a need to > ~advertise Router > ~IDs via OSPF. Is this something that is ever done in the real world. > ~Thanks for your help > ~ > ~ > ~ > ~ > ~Report misconduct > ~and Nondisclosure violations to [EMAIL PROTECTED] > ~ Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=32148&t=32042 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
