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North American Network Operators Group Date Prev | Date Next | Date Index | Thread Index | Author Index | Historical Re: Q: Sizes of Existing and Planned Fully Meshed IPSEC VPN (Tunnel Mode)
Yes. Fully meshed. N(N-1)/2 tunnels..................... Is around 5995 tunnels if I remember the correct formula off the top of my head. Straight IPSEC tunnels. No MPLS. No GRE. Just imagine a corporate customer to a big ISP, each site a single homed stub AS tunneling nicely across the ISP to other sites. Adding a few more sites monthly. Have not had a problem reported with routers dropping and long-time-lags with tunnels being re-established. Would be interested in hearing from large ISPs to see who has a running N(N-1)./2 fully meshed VPN where N>110 and what potential problems they have and how to mitigate against problems. Thanks! Finest Regards, Tim www.silkroad.com ----- Original Message ----- From: "Rodney Thayer" <[email protected]> To: <[email protected]> Sent: Tuesday, October 23, 2001 7:54 PM Subject: Fwd: Q: Sizes of Existing and Planned Fully Meshed IPSEC VPN (Tunnel Mode) > > I assume "fully meshed" means each node connects to each other > node, so each node has 109 tunnels (110 total). > I also assume "Cisco IPSEC based VPN" means IPsec (rfc 2401/2411/etc.) > and not MPLS-only. > > In that case, 120 is not 'large' according to the vendor > community -- 'large' starts at around 5000 tunnels. I suspect that, > in nature (or in the land of the Nanogians) that under 1000 is > more like a 'large' one. > > On the other hand, drop one box with 119 tunnels set up and > restart it and time how long it takes to re-initiate all 119 > tunnels, and you may very well be unhappy. > > >From: "Tim Bass" <[email protected]> > > >We have a Cisco IPSEC based VPN with over 110 edge routers > >in a full tunnel-mode mesh, mostly 'big hunking routers' with > >average CPU utilization under 15 percent. The VPN is > >controlled by a single organization, under centralized admin. >
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