Re: RTP under EIGRP

Charles,

On a LAN segment, it doesn't put the neighbor's sequence number in the
Update, so:

R1 sends update to R2/R3 on a LAN segment (multicast). Sequence=5, ACK=0
R2 and R3 both send ACKs with Sequence=0, ACK=5

I suggest running a packet capture to see what really happens.

On Tue, Feb 9, 2010 at 8:31 AM, <Charles.Henson_at_regions.com> wrote:

> I may be reading too much into this. Reading the Doyle books for fun.
> Routing TCP/IP Vol 1 Second Edition:
>
>
> ####################################################################################################################
> Page 264 Operation of EIGRP
> Reliable Transport Protocol
> The Reliable Transport Protocol (RTP) manages the delivery and reception of
> EIGRP
> packets. Reliable delivery means that delivery is guaranteed and that
> packets will be
> delivered in order.
> Guaranteed delivery is accomplished by means of a Cisco-proprietary
> algorithm known as
> reliable multicast, using the reserved class D address 224.0.0.10. Each
> neighbor receiving
> a reliably multicast packet unicasts an acknowledgment.
> Ordered delivery is ensured by including two sequence numbers in the
> packet. Each packet
> includes a sequence number assigned by the sending router. This sequence
> number is
> incremented by one each time the router sends a new packet. In addition,
> the sending router
> places in the packet the sequence number of the last packet received from
> the destination
> router.
>
> ####################################################################################################################
>
> If I have a segment with three routers on it and Router A sends an MCast to
> router B and C, then he should get an acknowledgement back from both. That
> makes sense. But then it says that Router A sends his own sequence number
> as well as the sequence number from the destination router to guarantee
> delivery. If there are multiple receiving routers (hence using multicast in
> the first place) then how is router A using a sequence number of a
> destination router to guarantee delivery. His own sequence number I
> understand. But the downstream router?
>
> Any help would be appreciated.
>
> Charles Henson
>
>
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-- 
Bryan Bartik
CCIE #23707 (R&S, SP), CCNP
Sr. Support Engineer - IPexpert, Inc.
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