DS-lite doesn't require the first DNS server be dual stack. Even the first DNS server is dual stack, its IPv4 address is difficult to delivery to the B4 element.
But, some DNS servers, at least one, in the ISP's network, have to be dual stack. They receive type A DNS requests contained in IPv6 packets and forward the requests to relevant IPv4 DNS server in current IPv4 Internet using IPv4 packets. Otherwise, all the A records in current Internet have to be mirrored to the IPv6 DNS servers in the ISP's network. I think this is impossible. I agree with Med's comments. IPv4 traffic should be offloaded if possible. -------------------------------------------------------------------------------- Zhenqiang Li 13911635816 Department of Network Technology China Mobile Research Institute 2010-06-01 -------------------------------------------------------------------------------- 发件人： Lee, Yiu 发送时间： 2010-05-31 10:45:20 收件人： lizhenqi...@chinamobile.com; softwires@ietf.org 抄送： 主题： Re: [Softwires] DNS question about DS-lite No. DS-lite doesn't require dual-stack DNS server. It needs normal DNS server running in the IPv6 network, and B4 proxies the v4 request over v6. I want to echo Med's comment in his previous email. It is not recommended to use AFTR to reach DNS server over v4 even thought it is possible. This will increase the AFTR load for obvious reason. On 5/30/10 10:38 PM, "lizhenqi...@chinamobile.com" <lizhenqi...@chinamobile.com > wrote: > Hi, Yes, DNS server in the ISP must be able to resolve all the A and AAAA > records. Does DS-lite require dual stack DNS server(s), i.e. DNS server(s) > with both IPv4 and IPv6 addresses, be deployed in the ISP's network? Dual > stack DNS server(s) needs to connect the DNS system in the IPv6-only network > and that in the IPv4-only Internet. Best > Regards, --------------------------------------------------------------------- > ----------- Zhenqiang Li 13911635816 Department of Network Technology China > Mobile Research > Institute 2010-05-31 -------------------------------------------------------- > ------------------------ 发件人： Lee, Yiu 发送时间： 2010-05-26 22:33:25 收件人： > lizhenqi...@chinamobile.com; Durand, Alain; softwires@ietf.org 抄送： 主题： Re: > [Softwires] DNS question about DS-lite The B4 element contains a DNS proxy > that will support DNS over v4 and proxy the DNS messages to the DNS server > over v6 in the ISP network. The DNS server in the ISP must be able to resolve > all the A and AAAA records. On 5/26/10 5:26 AM, > "lizhenqi...@chinamobile.com" <lizhenqi...@chinamobile.com > wrote: > Hi > Alain, > I have one question about DS-lite. Would you please clearify it? > Thanks. > > In your draft, you mention the B4 element can only get the > IPv6 address > of a DNS recursive server, and as such will have to perform > all DNS > resolution over IPv6. I want to know whether the DNS server can > resolve all > IPv4 nodes over IPv6 successfully. And how? Is it necessary that > the type A > DNS query packet travels through AFTR? Is there any requirement > for the DNS > server in the ISP core network? > > Best Regards, > > ------------------------------------ > Zhenqiang Li > 13911635816 > Department > of Network Technology > China Mobile Research Institute > 2010-05-26 > > _______________________________________________ > Softwires mailing list > > Softwires@ietf.org > > https://www.ietf.org/mailman/listinfo/softwires ______________________________ > _________________ Softwires mailing > list Softwires@ietf.org https://www.ietf.org/mailman/listinfo/softwires _______________________________________________ Softwires mailing list Softwires@ietf.org https://www.ietf.org/mailman/listinfo/softwires
