Re: Little OT: Variation on SRM vs. Config Sync [7:58317]
AFAIK there is no special interaction between SRM and HSRP. You might want to use the 'standby preempt delay ' feature to be sure that routing protocols have converged before the router is taking over hsrp active router functionality. http://www.cisco.com/warp/public/619/hsrpguide4.shtmlT hth Reinhold On Sat, Nov 30, 2002 at 12:39:15AM +, s vermill wrote: This is very closely related to another active thread but thought I should probably start another. I know better than to post on a Friday and expect much of an answer, but I could really use some insight on this one... I recently was looking at a network about to roll into production. It's a classic collapsed core design with redundant dist/core 6509s. I noticed that SRM was configured on each 6509. I also noticed that there was an HSRP instance per VLAN configured between the two chassis. So, in the event of an MSFC failure, assuming the failed MSFC was the active HSRP router for a given VLAN or group of VLANs, I guess the other chassis' designated MSFC would start picking up outbound traffic (normal HSRP stuff). In the mean time, the SRM process would be taking place on the chassis where the designated MSFC had failed. At what point, if at all, would the outbound traffic shift back to the chassis with the failed MSFC (assuming of course that the non-designated MSFC had successfully come online)? Is it a simple matter of whether or not preemt is configured? Or, would the switch to the other chassis ever even take place? Could it be that the non-designated MSFC would come online and immediately take over as the active HSRP router? That seems possible too. Maybe it comes down to how you set all the relevant timers? I couldn't find any example on CCO where SRM and HSRP were used together. In every case, SRM was used or HSRP was used with config sync. Never both together. Any thoughts? Any experience? It isn't an option at the moment to do too much experimenting. Besides, I'm not sure exactly how I would simulate a true MSFC failure to see what happens. Any thoughts there would also be appreciated. Thanks all... Scott Message Posted at: http://www.groupstudy.com/form/read.php?f=7i=58325t=58317 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: Little OT: Variation on SRM vs. Config Sync [7:58317]
Eric, Reinhold, Thank you. It makes sense that if the non-DR MSFC doesn't maintain a routing table (which it apparently doesn't), the standby HSRP router would need to handle traffic for at least a brief while. Delaying the preempt on the non-DR sounds like a wise move. Or maybe not using preempt at all. Thanks again, Scott Erick B. wrote: Scott, Normal HSRP rules would be in effect in this scenario I would say (haven't done this yet). If the failed unit had a higher HSRP priority and was configured to preempt then when it came back online it would become active HSRP router. Reinhold Fischer wrote: AFAIK there is no special interaction between SRM and HSRP. You might want to use the 'standby preempt delay ' feature to be sure that routing protocols have converged before the router is taking over hsrp active router functionality. http://www.cisco.com/warp/public/619/hsrpguide4.shtmlT hth Reinhold Message Posted at: http://www.groupstudy.com/form/read.php?f=7i=58342t=58317 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Little OT: Variation on SRM vs. Config Sync [7:58317]
This is very closely related to another active thread but thought I should probably start another. I know better than to post on a Friday and expect much of an answer, but I could really use some insight on this one... I recently was looking at a network about to roll into production. It's a classic collapsed core design with redundant dist/core 6509s. I noticed that SRM was configured on each 6509. I also noticed that there was an HSRP instance per VLAN configured between the two chassis. So, in the event of an MSFC failure, assuming the failed MSFC was the active HSRP router for a given VLAN or group of VLANs, I guess the other chassis' designated MSFC would start picking up outbound traffic (normal HSRP stuff). In the mean time, the SRM process would be taking place on the chassis where the designated MSFC had failed. At what point, if at all, would the outbound traffic shift back to the chassis with the failed MSFC (assuming of course that the non-designated MSFC had successfully come online)? Is it a simple matter of whether or not preemt is configured? Or, would the switch to the other chassis ever even take place? Could it be that the non-designated MSFC would come online and immediately take over as the active HSRP router? That seems possible too. Maybe it comes down to how you set all the relevant timers? I couldn't find any example on CCO where SRM and HSRP were used together. In every case, SRM was used or HSRP was used with config sync. Never both together. Any thoughts? Any experience? It isn't an option at the moment to do too much experimenting. Besides, I'm not sure exactly how I would simulate a true MSFC failure to see what happens. Any thoughts there would also be appreciated. Thanks all... Scott Message Posted at: http://www.groupstudy.com/form/read.php?f=7i=58317t=58317 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: Little OT: Variation on SRM vs. Config Sync [7:58317]
Scott, Normal HSRP rules would be in effect in this scenario I would say (haven't done this yet). If the failed unit had a higher HSRP priority and was configured to preempt then when it came back online it would become active HSRP router. --- s vermill wrote: This is very closely related to another active thread but thought I should probably start another. I know better than to post on a Friday and expect much of an answer, but I could really use some insight on this one... I recently was looking at a network about to roll into production. It's a classic collapsed core design with redundant dist/core 6509s. I noticed that SRM was configured on each 6509. I also noticed that there was an HSRP instance per VLAN configured between the two chassis. So, in the event of an MSFC failure, assuming the failed MSFC was the active HSRP router for a given VLAN or group of VLANs, I guess the other chassis' designated MSFC would start picking up outbound traffic (normal HSRP stuff). In the mean time, the SRM process would be taking place on the chassis where the designated MSFC had failed. At what point, if at all, would the outbound traffic shift back to the chassis with the failed MSFC (assuming of course that the non-designated MSFC had successfully come online)? Is it a simple matter of whether or not preemt is configured? Or, would the switch to the other chassis ever even take place? Could it be that the non-designated MSFC would come online and immediately take over as the active HSRP router? That seems possible too. Maybe it comes down to how you set all the relevant timers? I couldn't find any example on CCO where SRM and HSRP were used together. In every case, SRM was used or HSRP was used with config sync. Never both together. Any thoughts? Any experience? It isn't an option at the moment to do too much experimenting. Besides, I'm not sure exactly how I would simulate a true MSFC failure to see what happens. Any thoughts there would also be appreciated. Thanks all... Scott __ Do you Yahoo!? Yahoo! Mail Plus - Powerful. Affordable. Sign up now. http://mailplus.yahoo.com Message Posted at: http://www.groupstudy.com/form/read.php?f=7i=58318t=58317 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
