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New Member

IPv6 - NAT to v4; DHCP Relay

Simple network consisting of a 6506 switch with about 75 vlan interfaces. Want to add v6 to the interfaces for a hybrid network. V6 users need to access the Internet on v4.

Question 1 - Documentation is pretty clear on how to configure NAT-PT to go from v6 to v4 but it is not clear on the platforms the ipv6 nat commands are supported on. Further diggig shows that they are not supported on any 65xx platform. Therefore need to do router on a stick to a 2611XM for NAT. Has anyone done this? Any things I should be aware of?

Question 2 - Client wants a standalone DHCP and DNS server for all v6 clients. Looks like I need to use the ipv6 dhcp relay command on each vlan interface to point to the dhcp server. Similiar to ip helper-address in the v4 world. Simple enough, but it also seems like that command is not supported on the 65xx platform. Am I doing this right? Do I need to use autoconfig and/or dhcp server on the 6500? Does not seem right.

Thanks for any assistance.


Re: IPv6 - NAT to v4; DHCP Relay

If you have multiple IPv6-only or IPv4-only hosts that need to communicate, you may need to configure many static NAT-PT mappings. Static NAT-PT is useful when applications or servers require access to a stable IPv4 address. Accessing an external IPv4 DNS server is an example where static NAT PT can be used.

For the further detail follow the url which will help you :

New Member

Re: IPv6 - NAT to v4; DHCP Relay

Thanks for the response. I had tried the configs for NAT-PT as indicated inthe Cisco docs, including the one you referenced. I was able to get a static mapping to work, but further research showed that dynamic is not supported by RFC. The RFC referenced in the article, 2776, was depricated by RFC 4966, essentially making NAT-PT dynamic unsupported by any RFC. I was trying to do dynamic NAT-PT so IPv6 hosts could access the Internet.