Comments inline... --- Eric W wrote: > Dear Cisco Fans and Professionals, > > I need some friendly advice. There are different > opinions about > Cat6500(High availibility with Single Router Mode) > and (High availibility > with Dual MSFC Redundancy) > > Imagine you had 3 Cat65007s with Dual MSFC1 and Dual > Supervisor1A. > That is 6 MSFC's and 6 Supervisor engines. > > You have over 1500 users to support with 30VLANs > that need interconnecting > routing via EIGRP. Some user applications are > sensitive to packet loss. > > You have to provide minimium downtime in the case of > MSFC failer or > Supervisor failer. > > Question 1. Which would you implement (High > availibility with Single > router mode) or (High availibility with Dual MSFC > Redundancy) and why?
I would use SRM. From my experience the downtime (if any) is very minimal while it switches over to the redundant MSFC. The forwarding tables are downloaded to the sup so when primary fails routing will still occur and after the redundant comes up and is online for 2 minutes (default) the new tables will be downloaded and become active. The 2 minute (120 sec) timer is adjustable in newer code (7.1.1 I believe) incse it takes longer than 2 mins for your network/routing to finish converging on a failover. The other HA MSFC redundant option (config-sync) is ok and works, but has limitations with some protocols. Plus you have all the alt stuff to deal with, extra IP address usage, extra neighbor adjancies, etc. It doesn't take much time to change between the 2 (SRM and config-sync) so you could see which you like better if you have a lab or flexible environment to work in. Average cutover time per box is 3-4 minutes if things go smoothly and I've done the conversion live without taking a hit. > Question 2. Is was brought to my attention that > running dual MSFC > redundancy with a high number of VLANS would cause > the EIGRP process to run > very high. As you know EIGRP is a very noisy > protocol. Query storms.. > Implementing EIGRP passive interface on all VLAN > interfaces except the > management VLAN would help the EIGRP process to run > low. Are query storms > an issue to worry about even after the passive > interface is issued on > client/user VLANS? With newer versions of IOS you can include the network mask with the network statement under EIGRP so only those networks (interfaces) are in EIGRP. You could also use the EIGRP stub feature to reduce the querys. > > Regards, > Eric Washington > Network Engineer CCNP > > Thanks in advance for your input Cisco Professionals __________________________________________________ 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=7&i=58312&t=58312 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
