LVS
lvs-users
Google
 
Web LinuxVirtualServer.org

Re: [lvs-users] keepalived - VRRP setup with no master

To: "LinuxVirtualServer.org users mailing list." <lvs-users@xxxxxxxxxxxxxxxxxxxxxx>
Subject: Re: [lvs-users] keepalived - VRRP setup with no master
From: Alexandre Cassen <acassen@xxxxxxxxxx>
Date: Fri, 09 Jul 2010 10:24:10 +0200
On Thu, 2010-07-08 at 23:22 +0200, Sander Klein wrote:
> Replying to my own mail...
> 
> > I think you can give both directors the same priority. A director that
> is
> > in backup state and receives a vrrp packet with the same priority as
> it's
> > own should stay in backup state. But I can imagine it is possible that
> both
> > directors get in a state that they both start flapping between master
> and
> > backup state. I didn't look at any code, I only quickly reviewed the
> RFC.
> > So it might as well just work.
> 
> Keepalived 1.2.0 uses a modified VRRPv3 protocol. I just read in that RFC
> that if both priorities are the same, the one with the greater primary ip
> address becomes the master. Not sure how keepalived 1.2.0 handles this...
> 1.1.X uses VRRPv2. That has the previously described behavior.

1.2.0 has the same behaviour for IPv4 handling... Currently not
supported in the IPv6 version.

Concerning the modified VRRPv3 implementation in Keepalived. There is no
big difference between VRRPv2 and VRRPv3, authentication has been
removed in VRRPv3 considering auth is not important... But I will keep
it in place in Keepalived code since it can be useful. The only
modification I made for VRRPv3 is not to append IPv6 addresses in VRRP
packet since I really dont like that because it expose on the wire
topology informations, and since VRRP fsm is only drived by VRRP header
packet I simply removed IPv6 addresses adding in VRRP Packet. Well the
VRRPv3 header is also a simplification of previous VRRPv2 header, I kept
for the moment VRRPv2 header in code since it supports auth... 

cheers,
Alexandre


_______________________________________________
Please read the documentation before posting - it's available at:
http://www.linuxvirtualserver.org/

LinuxVirtualServer.org mailing list - lvs-users@xxxxxxxxxxxxxxxxxxxxxx
Send requests to lvs-users-request@xxxxxxxxxxxxxxxxxxxxxx
or go to http://lists.graemef.net/mailman/listinfo/lvs-users

<Prev in Thread] Current Thread [Next in Thread>