Hi, If 6rd-A and 6rd-B belong to the same 6rd domain, I don't see the routing loops.
washam ----- Original Message ----- From: Rémi Després <[email protected]> Date: Thursday, January 21, 2010 4:04 pm Subject: Re: [Softwires] routing loop issue//re: Please review 6rd To: Xu Xiaohu <[email protected]> Cc: [email protected] > Le 21 janv. 2010 à 08:42, Xu Xiaohu a écrit : > > > > > > +------------------------+ > > | | > > | | > > | IPv6 Internet | > > | | > > +------+----------+------+ > > | | > > | | > > +--+--+ +--+--+ > > +---+6rd-A+-----+6rd-B+--+ > > | +-----+ +-----+ | > > | | > > | IPv4 ISP | > > | +-------+ | > > +-------+ CPE-1 +--------+ > > +---+---+ > > | > > +-----+-----+ > > | | > > | IPv6 Site | > > +-----------+ > > > > In the above scenario, two 6rd BRs are configured with the same > address for > > anycast service. Assuming the nearest 6rd BR for the CPE is 6rd-A, > all IPv6 > > packets from the IPv6 site and destined to the IPv6 internet will be > > tunneled towards 6rd-A by the CPE. Once 6rd-A lost connections to > the IPv6 > > Internet, some failover mechanism should be used to direct these packets > > towards 6rd-B. > > > One possible solution is: 6rd-A withdraws the route to the > > IPv6 Internet, which was advertised in IPv4 ISP network previously, > as soon > > as its connection to the IPv6 Internet is lost. > > This is in my understanding the right solution, precisely because > protection against routing loops can be achieved by preventing tunnels > between BRs. > > > > Another solution is: > > establish a softwire tunnel between the two 6rd BRs for failover > route. With > > the latter solution, some normal packets tunneled in the softwire during > > failover will be filtered mistakenly. > > That's why the other solution should be preferred. > > RD > > _______________________________________________ > Softwires mailing list > [email protected] > https://www.ietf.org/mailman/listinfo/softwires > _______________________________________________ Softwires mailing list [email protected] https://www.ietf.org/mailman/listinfo/softwires
