[Xorp-users] Querry regarding domain wide address and primary address

[Bruce Simpson]

Hi,

Thanks for your question about PIM. I looked at RFC 4601 briefly to 
answer your question.

 This paragraph in the RFC should clarify the difference:

  "The primary address
   of a PIM neighbor is obtained from the source IP address used in its
   PIM Hello messages."

bhavin81 at iitb.ac.in wrote:
> Hello Friends,
>
>
>           I have got querry related with Primary address and domain
> wide address? What is the difference between those two addresses with
> any example if possible. Are those two addresse are related with the
> primary addresses and secondary addresses mentioned in RFC 4601?
> If not then what is the difference between primary and secondary addresses
> of router?
>   
In general, IPv4 addresses identify interfaces on-link, not nodes.

There are special situations where this is not the case, i.e. BGPv4 Anycasting, HSRP etc.

PIM, like many IETF protocols, uses one IPv4 address configured on an IPv4 PIM node to consistently refer to that node within the PIM protocol.

The definition of a secondary address is covered elsewhere in that RFC; they may either come from other interfaces, or be other addresses on the interface where the primary address is configured.

thanks,
BMS

P.S. It would be more useful if, when asking questions about PIM implementation, you could mention PIM in the subject line of your message.

P.P.S. You might want to direct non-XORP specific questions about protocol implementation to a more appropriate list, e.g. an IETF WG mailing list or perhaps end2end, as we need to keep xorp-users on topic. Thanks.