RE: Migration EIGRP-OSPF [7:5724]
Yes, We laid in OSPF over EIGRP since the administrative distance of EIGRP is 90 and OSPF is 110. We were then able to check the OSPF databases on each router to make sure that all routes are advertised correctly. The final step was to remove eigrp. This results in some downtime, but it was easier to schedule a block of downtime and cut over. Regards, David Wolsefer, CCIE #5858 -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf Of Dyson Kuben Sent: Thursday, May 24, 2001 5:59 AM To: [EMAIL PROTECTED] Subject: Migration EIGRP-OSPF [7:5724] anyone out there ever migrated a large-scale network from EIGRP to OSPF? Would you be able to share your experiences? Thanks, Dyson FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=6319&t=5724 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
RE: Migration EIGRP-OSPF [7:5724]
You also need to make sure that you have good address summarization if you want it to be successful. I've seen more than my fair share of networks that ran EIGRP, didn't have proper summarization and/or had a lot of redundancy. Because, out of the box EIGRP doesn't "require" you to build networks with summarization, etc. like OSPF. A few years back (before Cisco started publishing more details about scaling EIGRP) I saw several networks that were experiencing stability problems when running EIGRP and the thought was that OSPF would fix their problems. Most of these companies balked at the thought of re-addressing the network to properly support OSPF and stayed with EIGRP - using a lot of distribute-lists, etc. (although the same reasons that OSPF "requires" summarization would be of great benefit in an EIGRP network). I've found that binary math is not commonly held skill-set. What is the reason for going to OSPF in this instance, stability problems with EIGRP or multi-vendor support? In my experience people seem to view EIGRP as "easier" than OSPF - while probably true in really small networks, networks these days just seem to be getting bigger and the same planning required for a successful OSPF implementation is required for EIGRP. I haven't seen too many companies with all-Cisco routers and a healthy EIGRP network looking to change things - thus the question above. -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf Of David Wolsefer Sent: Tuesday, May 29, 2001 7:00 PM To: [EMAIL PROTECTED] Subject: RE: Migration EIGRP-OSPF [7:5724] Yes, We laid in OSPF over EIGRP since the administrative distance of EIGRP is 90 and OSPF is 110. We were then able to check the OSPF databases on each router to make sure that all routes are advertised correctly. The final step was to remove eigrp. This results in some downtime, but it was easier to schedule a block of downtime and cut over. Regards, David Wolsefer, CCIE #5858 -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf Of Dyson Kuben Sent: Thursday, May 24, 2001 5:59 AM To: [EMAIL PROTECTED] Subject: Migration EIGRP-OSPF [7:5724] anyone out there ever migrated a large-scale network from EIGRP to OSPF? Would you be able to share your experiences? Thanks, Dyson FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=6597&t=5724 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
RE: Migration EIGRP-OSPF [7:5724]
At 08:27 AM 5/31/01 -0400, R. Benjamin Kessler wrote: >What is the reason for going to OSPF in this instance, stability problems >with EIGRP or multi-vendor support? > >In my experience people seem to view EIGRP as "easier" than OSPF - while >probably true in really small networks, networks these days just seem to be >getting bigger and the same planning required for a successful OSPF >implementation is required for EIGRP. I haven't seen too many companies >with all-Cisco routers and a healthy EIGRP network looking to change >things - thus the question above. Well, a few points I would bring up is. Stuck in Active problem of EIGRP. As the updates are being done, the routers will stay in "active" mode (cannot receive new updates I believe). If the EIGRP network is big, it must wait for the very last router in the periphery to respond back. This could cause issues with convergence time. You may have to modify the timers to increase the hold time (which might cause bad convergence) since genuine requests might take so long that they will get "zonked" out and the the router will delete it's entry. This only happens in huge "AS" (in the EIGRP sense of an area of sorts). So, if the idea of using OSPF and breaking into "areas" is bad, you technically get the same issue with EIGRP, except in the form of ASes. Also, you are running a proprietary protocol now. Although it seems to work fine now. If say, they feel another vendor's product is superior in a particular aspect of their network, they might be hard pressed or you will need to do some redistribution/distribution lists which is probably going to be difficult as well. I suppose all in all it is still "easier" to use EIGRP. I agree wholeheartedly with your statements. The cost of going to OSPF might seem higher if they are really not that good with it. In that way it somewhat validates them sticking to EIGRP. -Carroll Kong Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=6616&t=5724 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
RE: Migration EIGRP-OSPF [7:5724]
an issue because Layer 3 wouldn't have allowed it. Given an all-Cisco network I would recommend EIGRP over OSPF any day. It has faster convergence and more flexibility than OSPF - there have to be some benefits to a proprietary protocol, right, otherwise no one would use it. I can't stress more that you have to have a solid network design to start and you have to limit the query scope of DUAL (effectively breaking the network into "areas") in order to have a stable, scalable network. If you don't do these things, at some point it will break and you'll be looking to migrate to OSPF. Sorry for the long response... I hope this helps, Ben -Original Message- From: Carroll Kong [mailto:[EMAIL PROTECTED]] Sent: Thursday, May 31, 2001 10:32 AM To: R. Benjamin Kessler Cc: [EMAIL PROTECTED] Subject: RE: Migration EIGRP-OSPF [7:5724] At 08:27 AM 5/31/01 -0400, R. Benjamin Kessler wrote: >What is the reason for going to OSPF in this instance, stability problems >with EIGRP or multi-vendor support? > >In my experience people seem to view EIGRP as "easier" than OSPF - while >probably true in really small networks, networks these days just seem to be >getting bigger and the same planning required for a successful OSPF >implementation is required for EIGRP. I haven't seen too many companies >with all-Cisco routers and a healthy EIGRP network looking to change >things - thus the question above. Well, a few points I would bring up is. Stuck in Active problem of EIGRP. As the updates are being done, the routers will stay in "active" mode (cannot receive new updates I believe). If the EIGRP network is big, it must wait for the very last router in the periphery to respond back. This could cause issues with convergence time. You may have to modify the timers to increase the hold time (which might cause bad convergence) since genuine requests might take so long that they will get "zonked" out and the the router will delete it's entry. This only happens in huge "AS" (in the EIGRP sense of an area of sorts). So, if the idea of using OSPF and breaking into "areas" is bad, you technically get the same issue with EIGRP, except in the form of ASes. Also, you are running a proprietary protocol now. Although it seems to work fine now. If say, they feel another vendor's product is superior in a particular aspect of their network, they might be hard pressed or you will need to do some redistribution/distribution lists which is probably going to be difficult as well. I suppose all in all it is still "easier" to use EIGRP. I agree wholeheartedly with your statements. The cost of going to OSPF might seem higher if they are really not that good with it. In that way it somewhat validates them sticking to EIGRP. -Carroll Kong Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=6747&t=5724 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]