Subject: [VRRP] VRRPv3 IPv6 RFC-5798 checksum

From: joe mcfar <[email-masked]>
Date: Mon, 7 May 2012 16:49:46 -0500

I am testing interoperability with one major vendor’s VRRPv3 IPv6
implementation and was surprised to  find that the vendor’s unit does not
include an IPv6 pseudo-header along with the VRRPv3 packet data when
calculating the checksum.   The current version of Wireshark (1.6.7) also
shows the VRRPv3 checksum as incorrect.  This would probably only be an
issue when trying to interoperate with another vendor’s implementation.

I’m interpreting RFC-5798 section 5.2.8 to say to calculate the checksum
over both the VRRPv3 packet data starting with the version field, AND over
the IPv6 pseudo-header (source, destination IPv6 addresses, upper layer
packet length, zero field, and next header of 112 for VRRP.)

Can someone on this mailing list verify my interpretation?

Thanks,

Joe McFarland

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From: Tomoyuki Sahara <[email-masked]>
Date: Thu, 10 May 2012 12:04:22 +0900

Hi,

> packet length, zero field, and next header of 112 for VRRP.)

Our implementation calculates the checksum with IPv6 pseudo-header as
described in RFC5798.  IMHO that vendor's implementation does not conform
to RFC5798 and so it is not interoperable with RFC5798 implementations.

Thanks,
Tomoyuki