RE: OSPF area 0 [7:45995]
Of course, two backbones where you intended one is generally a sub-optimal occurrence. At 03:33 PM 6/7/2002 -0400, Dusty Harper wrote: The network doesn't totally hose. Basically you get a second backbone. This leads to basically two different networks. In the example you provided, The backbone is still contiguous An example or where this might occur would be __ Area | |--- --|__|C B | A | Area 0 _| __ | | | |Area 2 |__|---|__|-- DE If the connectivity on link A went down, Area 0 then becomes divided, creating 2 separate networks 1) consists of subnet B, C, and possibly A 2) consists of D, E and possibly A possibly A is determined by what broke the connectivity. OSPF still functions, it just changes its behavior to accommodate the new topology. -Original Message- From: Carroll Kong [mailto:[EMAIL PROTECTED]] Sent: Friday, June 07, 2002 7:18 AM To: [EMAIL PROTECTED] Subject: Re: OSPF area 0 [7:45995] If I remember correctly, yes, Area 0 routers must always have a way to connect to each other. It does not have to be a full mesh (if that is what you mean by contiguous). Three routers in a mesh would be fine if one link broke. Now, if an area 0 router loses all connectivity to the other Area 0s (in your case, isolate one point of the triangle by losing TWO links), then your network gets borked. You will need a virtual link (if at all possible), or... well... your network is broken? :) Hi group, Is there any condition that OSPF area 0 must be contiguous?. I remembered read this some where on CCO. Is this true?. For a situation, three ospf routers connected in a triangle shape, what if one of the link goes down?. Any one experienced on this situation, please show me some documents related to this?. Thanks in advance, J. - Do You Yahoo!? Sign-up for Video Highlights of 2002 FIFA World Cup Nondisclosure violations to [EMAIL PROTECTED] -Carroll Kong Message Posted at: http://www.groupstudy.com/form/read.php?f=7i=46129t=45995 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
RE: OSPF area 0 [7:45995]
You should be able to anneal the Area 0. See Doyle, Vol. 1, pg 553. The implication is that the original design of Area 0 should be robust so that a link failure will not force a partition. Message Posted at: http://www.groupstudy.com/form/read.php?f=7i=46001t=45995 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: OSPF area 0 [7:45995]
If you are looking for documents, you might start with RFC 2328. Contiguous in this context refers to connectivity that continues without a break. In that sense, within an OSPF domain, it is necessary to maintain contiguous connectivity in the backbone. When contiguity is broken, the area is said to be partitioned. However, in your example, should a link in the triangle break, connectivity would still be contiguous as A connects to B which connects to C. Should a node in the triangle suffer outages of both connecting links, then contiguity would be severed and the area would be partitioned as that node would no longer maintain any active links to other backbone nodes. Pete At 08:58 PM 6/6/2002 -0400, Cisco Study wrote: Hi group, Is there any condition that OSPF area 0 must be contiguous?. I remembered read this some where on CCO. Is this true?. For a situation, three ospf routers connected in a triangle shape, what if one of the link goes down?. Any one experienced on this situation, please show me some documents related to this?. Thanks in advance, J. - Do You Yahoo!? Sign-up for Video Highlights of 2002 FIFA World Cup Message Posted at: http://www.groupstudy.com/form/read.php?f=7i=46016t=45995 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: OSPF area 0 [7:45995]
If I remember correctly, yes, Area 0 routers must always have a way to connect to each other. It does not have to be a full mesh (if that is what you mean by contiguous). Three routers in a mesh would be fine if one link broke. Now, if an area 0 router loses all connectivity to the other Area 0s (in your case, isolate one point of the triangle by losing TWO links), then your network gets borked. You will need a virtual link (if at all possible), or... well... your network is broken? :) Hi group, Is there any condition that OSPF area 0 must be contiguous?. I remembered read this some where on CCO. Is this true?. For a situation, three ospf routers connected in a triangle shape, what if one of the link goes down?. Any one experienced on this situation, please show me some documents related to this?. Thanks in advance, J. - Do You Yahoo!? Sign-up for Video Highlights of 2002 FIFA World Cup Nondisclosure violations to [EMAIL PROTECTED] -Carroll Kong Message Posted at: http://www.groupstudy.com/form/read.php?f=7i=46010t=45995 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
RE: OSPF area 0 [7:45995]
The network doesn't totally hose. Basically you get a second backbone. This leads to basically two different networks. In the example you provided, The backbone is still contiguous An example or where this might occur would be __ Area | |--- --|__|C B | A | Area 0 _| __ | | | |Area 2 |__|---|__|-- DE If the connectivity on link A went down, Area 0 then becomes divided, creating 2 separate networks 1) consists of subnet B, C, and possibly A 2) consists of D, E and possibly A possibly A is determined by what broke the connectivity. OSPF still functions, it just changes its behavior to accommodate the new topology. -Original Message- From: Carroll Kong [mailto:[EMAIL PROTECTED]] Sent: Friday, June 07, 2002 7:18 AM To: [EMAIL PROTECTED] Subject: Re: OSPF area 0 [7:45995] If I remember correctly, yes, Area 0 routers must always have a way to connect to each other. It does not have to be a full mesh (if that is what you mean by contiguous). Three routers in a mesh would be fine if one link broke. Now, if an area 0 router loses all connectivity to the other Area 0s (in your case, isolate one point of the triangle by losing TWO links), then your network gets borked. You will need a virtual link (if at all possible), or... well... your network is broken? :) Hi group, Is there any condition that OSPF area 0 must be contiguous?. I remembered read this some where on CCO. Is this true?. For a situation, three ospf routers connected in a triangle shape, what if one of the link goes down?. Any one experienced on this situation, please show me some documents related to this?. Thanks in advance, J. - Do You Yahoo!? Sign-up for Video Highlights of 2002 FIFA World Cup Nondisclosure violations to [EMAIL PROTECTED] -Carroll Kong Message Posted at: http://www.groupstudy.com/form/read.php?f=7i=46051t=45995 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
