This was how I set up the last ISP network I worked on. All PE's had dual REs and P routers only had a single. The P's already have a back up in that there is another P router. Many customers only had a single link to a PE so the failure of an RE in that box would be catastrophic.
I must admit, I've only had to fail over to a backup RE twice in many years. Thanks Darren http://www.mellowd.co.uk/ccie > Date: Mon, 23 Jun 2014 09:36:26 -0700 > From: [email protected] > To: [email protected] > CC: [email protected] > Subject: Re: [j-nsp] Redundant RE setup useful? > > It also depends on your level of network resiliency. If you have two > separate devices where each device is fully capable of supporting all of > the functionality alone, then dual REs don't make a lot of sense as you can > just shut down one box. We see this sort of thing when designing route > reflectors or tiered reflectors. Also in core topologies where you can > lose one (or more) routers and still be able to handle all of your capacity > without degradation. > > For PE routers, though, dual RE can save your life. And for P routers > where you just don't have enough boxes (or circuits!) to pick up the slack > if a few die. > > Of course, if you can't design for failures centered around control plane > failures in a single RE box, then you need dual RE...so it might be best to > stick with dual RE to be safe anyway. > > > On Mon, Jun 23, 2014 at 6:38 AM, Scott Granados <[email protected]> > wrote: > > > I have seen one of the RE modules fail and the backup saved our bacon. > > There was a bad batch of SSD drive components that caused issues and the > > card to crash. I’ve also seen an upgrade fail and the disk not format > > correctly rendering the card useless. Again very remote possibility of > > happening to you but possible. > > > > On Jun 23, 2014, at 4:07 AM, Joerg Staedele <[email protected]> wrote: > > > > > Hi there, > > > > > > i am asking myself if it really makes sense to have a redundant RE setup > > in M and MX-series. Maybe some of you could tell me if they had a scenario > > where it really helped to prevent an outage. > > > > > > I am not talking about ISSU/NSSU feature where it is needed. > > > > > > We didn't have a failed RE since years so for now all our redundant > > setups seem not make any sense at all. > > > > > > What are your experiences? > > > > > > Regards, > > > Joerg > > > > > > > > > _______________________________________________ > > > juniper-nsp mailing list [email protected] > > > https://puck.nether.net/mailman/listinfo/juniper-nsp > > > > > > _______________________________________________ > > juniper-nsp mailing list [email protected] > > https://puck.nether.net/mailman/listinfo/juniper-nsp > > > > > > -- > *Tyler Christiansen | Technical Operations* > tyler <http://adap.tv/>@adap.tv <http://adap.tv/> | www.adap.tv > *m :* 864.346.4095 > _______________________________________________ > juniper-nsp mailing list [email protected] > https://puck.nether.net/mailman/listinfo/juniper-nsp _______________________________________________ juniper-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/juniper-nsp
