Re: OSPFv3 fwd'ing address

[Acee Lindem <[e-mail]>]

Hi Mike,

Mike Fox wrote:

>Naiming Shen wrote:
>
>  
>
>>But if we think of this problem in another way, this 'nexthop' is only
>>an internal state within the router, what does anyone care if
>>I use a true 'link-local' address as a nexthop, or use the global
>>address as the nexthop which passed by the OSPF forwarding address?
>>I would not implement the IPv6 forwarding in a way to only
>>accept the link-local as nexthops.
>>    
>>
>
>That's how we implemented it.  For the AS-External forwarding address, our 
>implementation will accept any non-link-local address that is reachable 
>using the OSPF protocol.  As a user of an AS-External LSA we will send 
>packets for the external destination to the specified forwarding address 
>(if provided) and we assumed others would do the same, so as long as 
>routers in the AS can route to that forwarding address, it should work. 
>
>This significantly limits its usefulness, but it does work.  The place we 
>expect to see this used the most is for external default routes.  On our 
>platform the user can specify that an ASBR is to advertise an external 
>default route, and the user can optionally specify a forwarding address to 
>use on that route, with the restrictions that it can't be a link-local 
>address and it has to be an address or prefix that is routable in the OSPF 
>domain. 
>  
>
I don't see any problems with this as long as a global IPv6 address is 
available - either as the
next-hop gateway in the redistributed route or explicitly specified. I 
could document this case. .

>Mike
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