Re: RE: AppleTalk on FastEthernet interface

From: Dawit Birhanu (dawit@xxxxxxxxxxxx)
Date: Thu Jan 06 2000 - 14:36:59 GMT-3


   

Hi,

Finally, I managed to resolve the problem. The problem was with the RJ-45
connectors. What I did was as follows:

1. I removed AppleTalk from the FastEthernet interface of both
   routers, leaving only IP protocol.
2. Then I entered shut and then no shut on the FE interfaces -- now both FE
   interfaces are in up/up state. Cleared the interface stat. And
   generated traffic accross the link.

3. When I checked the interface using "show int fast 0/1", it showed
   significant level of output/input errors. However, this error level
   was tolerated by IP, and the interfaces stayed up/up.

4. I removed the cable and retested it using a cable tester. The tester
   showed that cable is fine.

5. It turned out that there was loose connection which makes the cable look
   good to the tester and performed poorly when used to connect the two
   routers.

6. Then we removed the loose connector and attached another connector. We
   reconfigured AppleTalk EIGRP. This time it worked.

I think what happend is as follows:

AppleTalk is not as tolerant to input/output error as is IP. Moreover,
when AppleTalk detects an unacceptable level of error, it tells the
interface to go down rendering it unavailable to other protocols such as
IP. This, I think, is a violation of the OSI model. When AppleTalk,
declares a link (or interface) to be unacceptable, it shouldn't interfer
with other protocols' decision and declare the interface unacceptable for
all protocols. Some protocols are designed to tolerate higher error rate.

Dawit

On Thu, 6 Jan 2000 Pramod.Daptardar@sita.int wrote:

> Hi
>
> Can you try half-duplex or full-duplex command on Both fast ethernet
> interfaces or alternatively
> observe output of show int fastethernet , to see if both interfaces are in
> same duplex mode.
>
> Regards
>
> Pramod



This archive was generated by hypermail 2.1.4 : Thu Jun 13 2002 - 08:22:43 GMT-3