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Community Member

ISDN BRI (spoofing) and NetView snmp (dormient)

When the the ISDN interface BRI0/0 is not on call the router shows "BRI0/0 is up (spoofing), line protocol is up (spoofing)".

I know this is needed for IP to see the interface viable.

But when the call is estabilished and the router says "BRI0/0 is up, line protocol is up (spoofing)", why the line protocol is still spoofing?

Or customer problem is that NetView 6000 snmp network management station shows the interfaces BRI0/0 in a state of "dormient" and B-channels BRI0/0:1 and BRI0/0:2 "dormient" when there is non call and UP when the call is estabilished.

The fact is that the BRI0/0 remains always "dormient" and the color of the interface does not change to alert the operator that the iSDN is UP.

I am not in charge for the NetView management station, but can someone help me to give an answer to the customer?

Thanks

Franco Feri

2 REPLIES
Silver

Re: ISDN BRI (spoofing) and NetView snmp (dormient)

After the interesting packets are defined, they must be routed properly for a call to be initiated. The routing process depends on two things: routing table entries and an "up" interface over which to route packets. In order for packets to be routed to and through an interface, that interface must be up/up as seen in a show interfaces output:

router# show interfaces ethernet 0

Ethernet0 is up, line protocol is up

Hardware is Lance, address is . . .

What happens to a dialer interface that is not connected? If protocol is not up and running on the interface, the implication is that the interface itself will not be up. Routes which rely on that interface will be flushed from the routing table, and traffic will not be routed to that interface. The result is that no calls would be initiated by the interface.

The solution to counter this possibility is to allow the state up/up (spoofing) for dialer interfaces. Any interface can be configured as a dialer interface. For example, a Serial or Async interface could be made into a dialer by adding the command dialer in-band or dialer dtr to the interface's configuration. These lines are unnecessary for interfaces that are by nature a dialer interface (BRIs and PRIs). The output for a show interface will look like this:

router# show interfaces bri 0

BRI0 is up, line protocol is up (spoofing)

Hardware is BRI

Internet address is . . .

In other words, the interface "pretends" to be up/up so that associated routes will remain in force and so that packets can be routed to the interface.

Community Member

Re: ISDN BRI (spoofing) and NetView snmp (dormient)

Hello Mary,

As i aint a ISDN expert,i do understand your comments.Thank you for clarifying.The issue mith me is that a customer of mine has the same issue.

BUT sometimes he gets the status of up(spoofing) - up (spoofing) in his BRI interfaces and dialer interfaces like in this example:

BRI0 is up (spoofing), line protocol is up (spoofing)

Hardware is BRI

MTU 1500 bytes, BW 64 Kbit, DLY 20000 usec,

reliability 255/255, txload 1/255, rxload 1/255

Encapsulation PPP, loopback not set

Last input 00:01:58, output never, output hang never

Last clearing of "show interface" counters 1y48w

Input queue: 0/75/277/0 (size/max/drops/flushes); Total output drops: 0

Queueing strategy: fifo

Output queue :0/40 (size/max)

5 minute input rate 0 bits/sec, 0 packets/sec

5 minute output rate 0 bits/sec, 0 packets/sec

6103321 packets input, 24625954 bytes, 0 no buffer

BRI0:1 is down, line protocol is down

Hardware is BRI

MTU 1500 bytes, BW 64 Kbit, DLY 20000 usec,

reliability 255/255, txload 1/255, rxload 1/255

Encapsulation PPP, loopback not set

Keepalive set (12 sec)

LCP Closed

Closed: CCP

Last input 00:02:05, output 00:02:03, output hang never

Last clearing of "show interface" counters 1y48w

Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0

Queueing strategy: fifo

Output queue :0/40 (size/max)

5 minute input rate 0 bits/sec, 0 packets/sec

5 minute output rate 0 bits/sec, 0 packets/sec

86459 packets input, 8386773 bytes, 0 no buffer

Received 0 broadcasts, 0 runts, 0 giants, 0 throttles

0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort

86052 packets output, 6931463 bytes, 0 underruns

0 output errors, 0 collisions, 0 interface resets

0 output buffer failures, 0 output buffers swapped out

804 carrier transitions

Dialer1 is up (spoofing), line protocol is up (spoofing)

Hardware is Unknown

Description: - Dialer DDR to primary CAS PBRU474 and backup PBRU476

Internet address is 57.194.214.73/23

MTU 1500 bytes, BW 8 Kbit, DLY 20000 usec,

reliability 255/255, txload 1/255, rxload 1/255

Encapsulation PPP, loopback not set

DTR is pulsed for 1 seconds on reset

Last input never, output never, output hang never

Last clearing of "show interface" counters 1y48w

Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 135

Queueing strategy: fifo

Output queue :0/40 (size/max)

5 minute input rate 0 bits/sec, 0 packets/sec

5 minute output rate 0 bits/sec, 0 packets/sec

83857 packets input, 8329028 bytes

83060 packets output, 6862196 bytes

What could be the cause here?

This is giving false alarms appearantly in their network management tool.

Thanks for all usefull info.

Kurt

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