-----Ursprungligt meddelande----- Fr�n: Chuck Larrieu [mailto:[EMAIL PROTECTED]] Skickat: den 25 september 2000 04:50 Till: Andre Riscalla; [EMAIL PROTECTED] �mne: RE: Dual Homing to OSPF Area 0 A segmented area is of no concern so long as there is no overlap of address space. In your case, it would appear that there might be such an overlap. A temporary repair can be made using a virtual link. ( an interesting aside - the OSPF RFC makes short mention of segmented areas. There is nothing in the RFC prohibiting duplication of area numbers. I have done a small lab using duplicate area numbers with no problem. All routes passed. I posted the results here a month or so back, if memory serves. ) In terms of points of failure, the question is how much redundancy do you want and need, given your business operation? The world is a single point of failure, said one person whom I respect. If your business is such that 1) you require 100% availability and 2) you have the money to pay for it, then yes your design should include not only full meshing, but multiple redundant routers ( HSRP ) as well as cold spares on premise at all locations. You should also have Smart Net 7x24 by 4 hour, and locate your critical operations only within a couple of hours drive of Cisco distribution points ( usually near major airports. ) Food for thought. Chuck -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]] On Behalf Of Andre Riscalla Sent: Sunday, September 24, 2000 7:35 PM To: [EMAIL PROTECTED] Subject: Dual Homing to OSPF Area 0 Hi All, I ran into an interesting OSPF problem: I have multiple distribution routers (D1, D2) in OSPF area 10, dual homed to ABR's C1 and C2. C1 and C2 have a link between them, in area 0. I am doing summarization into area 0. The picture below summarizes this situation: /----\ Area_0 C1 C2-------------^ | \ /| | | \/ | v Area_10 | / \ | | / \| D1 D2 What happens if the links between D1 & C2 and D2 & C1 fail at the same time? Communication between D1 & D2 now has to occur through C1 & C2 over area 0, which means I have segmented area 10. How is this design normally done, dual homing the "D" routers to multiple "C" routers. If the "C" routers are only ABRs for one area, does it make sense to have the link between C1 & C2 in area 10 as well? Any feedback is greatly appreciated. Thanks. AR- -- Contrary to popular belief, Unix IS user friendly. It just happens to be very selective about who it decides to make friends with. +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- Andre Riscalla Network Specialist - Internet [EMAIL PROTECTED] 514-940-5664 Network Engineering AT&T Canada +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- **NOTE: New CCNA/CCDA List has been formed. For more information go to http://www.groupstudy.com/list/Associates.html _________________________________ 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] **NOTE: New CCNA/CCDA List has been formed. For more information go to http://www.groupstudy.com/list/Associates.html _________________________________ 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] **NOTE: New CCNA/CCDA List has been formed. For more information go to http://www.groupstudy.com/list/Associates.html _________________________________ 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]
