On Thu, 3 Aug 2000, Sim, CT (Chee Tong) wrote:
> However, I would like to ask you
>
> 1)what is mean by EIR on the Frame relay? Can any one tell me?
Might you mean CIR? Committed information rate?
>
> 2)If I found the link is up between two router,
Is this a circuit that has worked in the past and stopped, or a new turn-up?
The answer to this question can cause a different approach to troubleshooting.
Assuming frame-relay encaps because you mentioned frame-relay in question 1...
>
> router A
> interface is up and protocol is down
> modem status is DCD=up DSR=up DTR=up RTS=up CTS=up
The physical circuit to the router is OK. It _probably_ is talking to the
frame-relay switch OK, especially if the circuit has worked in the past and
just quit. The DCD=up and CTS=up show that the physical layer is good, or
at least connected.
If "sho int" contains a line like:
LMI enq sent 209473, LMI stat recvd 209473, LMI upd recvd 0, DTE LMI up
then the "DTE LMI up" verifies that this router is good to the switch.
"sho frame pvc" should show the DLCI as USAGE = LOCAL and STATUS = ACTIVE
for the DLCI of the circuit between the two routers if everything is happy.
If the remote router is not happy, then you'll see STATUS = INACTIVE. If the
PVC isn't built in the switch, you'll see STATUS = DELETED or nothing at
all for that DLCI if you're using inarp.
>
> but at the router B,
> the interface is down and protocol is down,
> the modem status is DCD=down DSR=up DTR=up RTS=up CTS=down.
This router or its CSU/DSU if external is not communicating with the
frame-relay switch. Look for trouble on the physical wiring to this
router. In the real world, this is almost always a telephone company
issue. In a lab, it could be a bad or miswired cable.
> What is likely the cause of the problem?
A tech at the telco closest to router B looped its NIU while mis-reading
a circuit ID trying to fix something else. (That's the most likely cause,
but don't expect to find it on the test.)
> Is that the modem of router B got
> problem or serial port of router B got problem or the link within the
> service provider got problem
If this is a previously working circuit, it's most likely a telco issue
between the frame-relay switch and router B. A loopback plug on the line
to the CSU (1-4, 2-5 for T1, 1-7, 2-8 for 56K) cusing DCD to go "up" will
isolate it.
Note: Telephone companies are notorious for blaming the customer and
looping the wrong circuit. Carry a loopback plug in your tool kit. When
telco claime "It's good to the NIU", plug your loopback plug into their
smartjack and ask them to run to it. Unplug it and see if the loop goes
down.
In the real world, if a circuit has been working fine for months or years
and suddenly quits, what has probably happened is that a telco tech, in
the process of troubleshooting something else, accidentally hopped on to
your circuit and put a smartjack in loopback. When you call in to report
the problem, they'll test things and knock down the loop that they put
up by mistake earlier. Then it will work again, and get closed out as
another "came clear while testing." The second most likely cause is that
someone clipped a butt-set on your data pair which wasn't documented
correctly, didn't hear dial tone, and swiped it for something else. This
takes longer to fix, but telco will still probably claim "came clear
while testing" even though they know better. A lot depends on the competence
of your local telephone company.
Hint: If they are spending millions of dollars right now on a massive,
saturation TV ad campaign just to announce that they're changing their
name while under the threat of a labor strike, then perhaps they have their
priorities wrong.
--
Jay Hennigan - Network Administration - [EMAIL PROTECTED]
NetLojix Communications, Inc. NASDAQ: NETX - http://www.netlojix.com/
WestNet: Connecting you to the planet. 805 884-6323
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