And one other tidbit:
EIGRP implements poison reverse.
I did some sniffing and here's what I saw:
Router A boots and sends hellos to 224.0.0.10
Router B boots and sends hellos to 224.0.0.10
Router B sends update directly to Router A specifying 4 networks Router B
can get to
Router A ACKS
Router A sends update saying that the 4 networks are unreachable, delay =
FFFFFFFF
Router B ACKS
Router A sends update directly to Router B specifying 1 network Router A
can get to
Router B ACKS
Router B sends update saying that the network is unreachable, delay =
FFFFFFFF
Router A ACKS
Priscilla
At 04:40 PM 7/9/01, Patrick Ramsey wrote:
>Some additional info on eigrp packets: (from notes after taking the routing
>class)
>
>1,hello: multicast 224.0.0.10 > every 5 seconds or 60 secs on t1 or less
>2,update: the actual info received for routing
>3,query: the packet sent out to request and update
>4,reply:answer to query
>5,ack:reliable packet received
>
>2-4 are connection based, whereas 1 and 5 are not.
>
>Just a tidbit...You pretty much have everything else the class covered.
>
>-Patrick
>
> >>> "John Feuerherd" 07/09/01 04:17PM >>>
>Thanks for all the replies (Expect for abc),
> I do however feel like we have missed the question. I wanted to
> know if
>IGRP and EIGRP use the same method in discovering networks. Not how or if
>they establish neighbors. I understand that, but that is not how they
>discover networks. With OSPF neighbor adjacencies are not how it discovers
>networks, it uses LSAs to do that. I have done a lot of reading on this and
>this is where I am at now:
>
>These are the steps:
>1) Upon startup, a router uses Hellos to discover neighbors and to identify
>itself to neighbors. When a neighbor is discovered, EIGRP will attempt to
>form an adjacency with that neighbor. (This is all done across the multicast
>address 224.0.0.10) This information is stored in the neighbor table. (Ok we
>have established neighbor relationships, but no network information has been
>exchanged)
>NOTE - ABC you said that IGRP uses DV algorithm to establish neighbors, this
>is not true. IGRP does not establish neighbors (no neighbor table). A lot of
>talk from someone who can't even get the facts right.
>
>2) After an adjacency with a neighbor established, the router will receive
>updates from its neighbors. The updates will contain all routes known by
>the sending router. (Plus the metrics - same as IGRP +256) It does this
>using the Reliable Transport protocol, which ensures guaranteed delivery of
>the routing updates. This is the part where I think that question might have
>been referring to. Like a DV routing protocol (IGRP and RIP) the neighbors
>sends their whole routing table in one shot. This is only done once, and
>then only changes are sent after that.
>
>3) It then goes on to use the DUAL algorithm, which is out of the scope of
>my question so I wont bore you with details.
>
>After my reading I have decided that there are some similarities on how both
>IGRP and EIGRP discover networks, but I have concluded that they are not the
>same. Let me know what you think.
>
>One last note - ABC before you go attacking someone else's knowledge level
>with out even knowing what they know, maybe you should take a long look at
>your own ignorance. Sure I don't know everything, and I KNOW that I don't
>know enough to be a CCIE (hence the comment "studying for my CCIE"), but
>that of course is why I am posting questions on this board. So instead of
>creating a negative atmosphere on the board, why don't you try helping, or
>just get off all together. Just a though*.
>
>Thanks again everyone for your replies!
>JF
________________________
Priscilla Oppenheimer
http://www.priscilla.com
Message Posted at:
http://www.groupstudy.com/form/read.php?f=7&i=11587&t=11273
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