Re: ISP OSPF Design [7:65316]
Good morning all, Does anyone out there know of either a good white paper or book that shows some ISP OSPF designed networks? I am trying to find something that is more geared towards service providers rather than corporate network LAN design. Thanks as always... Chris Berkowitz: Building Service Provider Networks (Wiley) Greene and Smith: Cisco ISP Essentials (Cisco Press) Having given those references, ISIS is more common than OSPF as an ISP IGP. I have seen good designs with OSPF, generally where there were lots of servers in the ISP or there were other needs for finer-grained route propagation than is typical in ISIS. To clarify something in another post, however, an ISP needs _both_ an IGP and BGP. Many larger ones will also use (G)MPLS setup. Message Posted at: http://www.groupstudy.com/form/read.php?f=7i=65365t=65316 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: ISP OSPF Design [7:65316] (hit send too soon) [7:65366]
Good morning all, Does anyone out there know of either a good white paper or book that shows some ISP OSPF designed networks? I am trying to find something that is more geared towards service providers rather than corporate network LAN design. Thanks as always... Chris Berkowitz: Building Service Provider Networks (Wiley) For some freebies, http://www.nanog.org/mtg-9910/ospf.html Greene and Smith: Cisco ISP Essentials (Cisco Press) Having given those references, ISIS is more common than OSPF as an ISP IGP. I have seen good designs with OSPF, generally where there were lots of servers in the ISP or there were other needs for finer-grained route propagation than is typical in ISIS. To clarify something in another post, however, an ISP needs _both_ an IGP and BGP. Many larger ones will also use (G)MPLS setup. Message Posted at: http://www.groupstudy.com/form/read.php?f=7i=65366t=65366 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: ISP OSPF Design [7:65316]
Hi. Usually ISPs use Integrated IS-IS for their IGP (at least the ones I've dealt with). IS-IS can deal better with large flat networks and has better convergence characteristics (milliseconds vs. 6-46s). That said, you could certainly use OSPF as your IGP. On CCO there is a document called ISP Design Fundamentals which could help here (too lazy to look it up now...) Best regards, Oliver Chris Headings sagte: Good morning all, Does anyone out there know of either a good white paper or book that shows some ISP OSPF designed networks? I am trying to find something that is more geared towards service providers rather than corporate network LAN design. Thanks as always... Chris Nondisclosure violations to [EMAIL PROTECTED] -- Oliver Hensel telematis Netzwerke GmbH mailto:[EMAIL PROTECTED] Siemensstrasse 23, D-76275 Ettlingen Tel: +49 (0) 7243-3448-0, Fax: -498 visit us: http://telematis.com Message Posted at: http://www.groupstudy.com/form/read.php?f=7i=65353t=65316 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
RE: ISP OSPF Design [7:65316]
I am assuming you are talking about across the Backbone of the ISP. The internal protocol used by some large ISP's is ISIS. If you are talking about external protocols look at BGP. Daniel Ladrach CCNP, CCNA WorldCom Some, but not all use ISIS. The biggest service provider OSPF network I know of, admittedly a fairly special case, was MCI's frame relay aggregation network -- it IP routed up to the ATM switched core. Message Posted at: http://www.groupstudy.com/form/read.php?f=7i=65367t=65316 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
RE: ISP OSPF Design [7:65316]
Thanks all!!! Chris Message Posted at: http://www.groupstudy.com/form/read.php?f=7i=65439t=65316 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
RE: ISP OSPF Design [7:65316]
normally ISP networks are with BGP. Message Posted at: http://www.groupstudy.com/form/read.php?f=7i=65317t=65316 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
RE: ISP OSPF Design [7:65316]
I am talking about the IGP. We do run BGP to our 2 different upstream providers... Chris Message Posted at: http://www.groupstudy.com/form/read.php?f=7i=65325t=65316 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: ISP OSPF Design [7:65316]
At 03:54 PM 3/13/2003 +, Chris Headings wrote: Good morning all, Does anyone out there know of either a good white paper or book that shows some ISP OSPF designed networks? I am trying to find something that is more geared towards service providers rather than corporate network LAN design. Here are some thoughts. First off, keep your IGP as small as possible by pushing as much routing as possible in BGP. Ideally, you'll only use OSPF for loopback and link reachability. Use multiple areas only when the sheer amount of routers/interfaces demands it. Since you have few routes in OSPF, you won't be using multiple areas to enable address summarization. The amount of routers one has before one needs isolation via areas is a matter of some debate, but assuming you have some service provider class routers, should be at least in the 50-100 range at minimum and could likely approach much higher numbers. If you must use multiple areas, configure them as NSSA. You shouldn't have any externals in your network to begin with, but some odd situations tend to demand it and therefore if you must bring them in, NSSA will allow you some control over their flooding. Beyond that, try nanog archives for metric use guidelines if you intend to do some TE in OSPF (there are a few different approaches to metric use in IGPs). Also nanog is likely to have some timer tweaks that will be helpful in speeding convergence. Book wise, I've not seen one that covers IGP/BGP in tremendous detail. Howard Berkowitz has a pretty useful service provider book (Building Service Provider Networks / Wiley) that covers a variety of ISP oriented details that would likely be a good read if you are new to ISP networking, but most of the decent ISP best-practise like details from a router configuration perspective have usually been found at or near the NANOG community. Phillip Smith from Cisco has published his ISP Essentials set of guildelines as a book which has a lot of very useful information, but can also be found in pdf form. Pete Thanks as always... Chris Message Posted at: http://www.groupstudy.com/form/read.php?f=7i=65345t=65316 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
RE: ISP OSPF Design [7:65316]
I am assuming you are talking about across the Backbone of the ISP. The internal protocol used by some large ISP's is ISIS. If you are talking about external protocols look at BGP. Daniel Ladrach CCNP, CCNA WorldCom -Original Message- From: Chris Headings [mailto:[EMAIL PROTECTED] Sent: Thursday, March 13, 2003 10:55 AM To: [EMAIL PROTECTED] Subject: ISP OSPF Design [7:65316] Good morning all, Does anyone out there know of either a good white paper or book that shows some ISP OSPF designed networks? I am trying to find something that is more geared towards service providers rather than corporate network LAN design. Thanks as always... Chris Message Posted at: http://www.groupstudy.com/form/read.php?f=7i=65339t=65316 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
RE: ISP OSPF Design [7:65316]
Chris Headings wrote: Good morning all, Does anyone out there know of either a good white paper or book that shows some ISP OSPF designed networks? I am trying to find something that is more geared towards service providers rather than corporate network LAN design. Howard Berkowitz's book Building Service Provider Networks has some discussion of OSPF usage as the IGP in an ISP. It doesn't include a lot of detail on any particular OSPF designed networks, but it has good informatin on IS-IS versus OSPF, how to use OSPF with MPLS, OSPF covergence time, etc. It's a terrific book that you should get if you are charged with managing and enhancing an ISP's internal network. Priscilla Thanks as always... Chris Message Posted at: http://www.groupstudy.com/form/read.php?f=7i=65338t=65316 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
