Subject: [OSPF] Multiple Interfaces to a Single Link

From: "Ramana Koppula-G20085" <[email-masked]>
Date: Wed, 10 May 2006 22:45:28 +0800

Hi all,
 
Statement 1) From section 3.2.2 of OSPF for IPv6, "Locally originated
packets SHOULD NOT be passed on to OSPF. That is, the source IPv6
address should be examined to make sure this is not a multicast packet
that the router itself generated." This is one of the checks that need
to be done before the packet is sent for OSPF processing."
 
Statement 2) From section 3.9 of OSPF for IPv6, "This allows the router
to automatically detect that multiple router interfaces attach to the
same link, when a Hello packet is received with the router's link-local
address as the source address but with an Interface ID other than the
Interface ID for the receiving interface."
 
Doesn't the above two statements conflict in the case of Multiple
Interfaces to the same broadcast link. And also first condition is
checked for at IPv6 level while the other is at OSPF level. If the first
statement is true, the packet would be dropped at the IP level and is
not passed to OSPF.
 
I doubt the first statement if it should be re-written as "Locally
originated packets SHOULD NOT be passed on to OSPF. That is, the source
IPv6 address should be examined to make sure this is not a multicast
packet that the router itself generated from same interface" This is one
of the checks that need to be done before the packet is sent for OSPF
processing."
 
thanx
ramana
Hi all,
 
Statement 1) From section 3.2.2 of OSPF for IPv6, "Locally originated
packets SHOULD NOT be passed on to OSPF. That is, the source IPv6
address should be examined to make sure this is not a multicast packet
that the router itself generated." This is one of the checks that need
to be done before the packet is sent for OSPF processing."
 
Statement 2) From section 3.9 of OSPF for IPv6, "This allows the router
to automatically detect that multiple router interfaces attach to the
same link, when a Hello packet is received with the router's link-local
address as the source address but with an Interface ID other than the
Interface ID for the receiving interface."
 
Doesn't the above two statements conflict in the case of Multiple
Interfaces to the same broadcast link. And also first condition is
checked for at IPv6 level while the other is at OSPF level. If the first
statement is true, the packet would be dropped at the IP level and is
not passed to OSPF.
 
I doubt the first statement if it should be re-written as "Locally
originated packets SHOULD NOT be passed on to OSPF. That is, the source
IPv6 address should be examined to make sure this is not a multicast
packet that the router itself generated from same interface" This is one
of the checks that need to be done before the packet is sent for OSPF
processing."
 
thanx
ramana
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From: Acee Lindem <[email-masked]>
Date: Fri, 12 May 2006 16:05:41 -0400

Ramana,

I've updated the 3.2.2 text as follows. I believe this addresses your 
concern.

 o  Locally originated packets SHOULD NOT be processed by OSPF except
      for support of multiple interfaces attached to the same link as
      described in Section 3.9.  A locally originated packet is
      identified as packet with a source address equal to one of the
      router's local addresses.

I'd be interested in opinions on multi-interface per link support in 
general.

Thanks,
Acee

Ramana Koppula-G20085 wrote:

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