PPP negotiation failure..

[xtam1]

AvayaRouter(X330W-2USP[X.21])--Modem---Carrier1---FlagTel---Carrier2----Cat6513_flexWan(E1)

The problem is that during the ppp negotiation it always fail, the LCP get opened and then closed; The link is flapping every 30 seconds from UP UP to UP Down, even when it is UP UP i can not ping the remote end (Avaya Router).

After checking the output from debug ppp negotiation i noticed that LCP phase can be completed successfully but the IPCP phase is not successful..

What is wrong?!! Below is the debug output, controller and interface configs, as well as their show commands.

Regards

[pkhatri]

I have not gone through all your configs but I see that you are using an MTU of 300. Can you try removing the 'mtu 300' statement and then trying again...

Paresh.

[xtam1]

Thanks for the reply but it did not change anything, the situation is the same..

[Richard Burts]

Tam

I have looked at the configs and at the debug output that you posted. I note in the config that you specify the IP address on your interface and also specify the address of the peer. I do not usually see specification of the peer address and wonder why this is in the config?

The debug output is interesting. In going through the LCP phase there are a number of instances where your router sends "O CONFREQ [Open] id 61 len 14" and gets no response but there are instances where it sends CONFREQ and does get a response. But in IPCP it is sending CONFREQ to negotiate/confirm the IP addresses and it never gets any response. I believe this is the major problem. Why does the remote router never respond in the IPCP. Without seeing the remote side it makes me wonder if the interface on the remote is configured for IP?

HTH

Rick

[xtam1]

Thanks Rick for the reply, Yes, the remote interface is configured for IP.

[xtam1]

MTU 1500

Bandwidth 1984

the IPCP still having problems, PPP negotiation fails,

What is going on?!!

Regards

[Richard Burts]

Tam

From looking at the debug messages the biggest problem is that your router is sending PPP CONFREQ in IPCP trying to negotiate the addresses used and it is getting no response from the other end. Why is the other end not responding?

What can you tell us about the other end? Is it possible to get the configuration of the interface on the other end?

HTH

Rick

[xtam1]

AvayaRouter(X330W-2USP[X.21])--Modem---Carrier1---FlagTel---Carrier2----Cat6513_flexWan(E1)

attached is the Avaya router configuration and the show interface serial output.

Regards.

[Richard Burts]

Tam

Thanks for posting the additional information. I believe that it has supplied the information to identify the problem. The Avaya has configured compression on the serial ( ip rtp header-compression) and the other router has not. I am convinced that this is why IPCP is not completing (and why there were so many attempts in LCP that got no response). Either configure compression on your router or remove compression on the Avaya.

Try this and let us know how it works.

HTH

Rick

[xtam1]

Hi again Rick,

i did the compression on my side and it did not work, and i removed the compression from their side then removed the comperssion from my side and it did not work as well, i am stuck and i do not know what to do?!!!

but i noticed the following from the show interface serial on the Avaya router:

509 input errors, 375 CRC, 80 abort

do you think this might be the reason preventing the link coming up?!! (from my side i do not see any errors under the interface serial)

Regards.

[Richard Burts]

Tam

I am surprised that removing compression on both sides did not fix the problem. And having compression on only one side IS a problem, so it needed to be fixed anyway.

If that is not the only problem then we need to look for something else. I notice that the Avaya has configured the interface for VOIP ( VoIP mode enabled ) and the other router does not. What happens if you remove the voip-queue and queue-limit 1 12 from the Avaya?

I also wonder if it might be helpful to reboot one or both routers? Or if you can not reboot then perhaps a shut/no shut on the interfaces?

HTH

Rick

[xtam1]

Hi Rick,

I removed voip-queue , queue-limit 1 12 and VOIP mode is disabled from the Avaya, shut the interfaces and enabled them again; nothing changing..!!

i contacted carrier 2; they are using a converter to convert from G.703 to X.21 and they told me that they do not use channel 16..!!!

What do you think i should do?!!

Regards

[nbhandarkar]

Hi xtam1,

Can u try configuring "ppp authentication chap" or pap on both sides and check?

[xtam1]

i just run the deb ppp neg:

Aug 2 17:09:58.491: Se0/1:0 IPCP: I CONFREQ [ACKrcvd] id 31 len 26

Aug 2 17:09:58.491: Se0/1:0 IPCP: Address 192.168.1.1 (0x0306C0A80101)

Aug 2 17:09:58.491: Se0/1:0 IPCP: CompressType RTP iphc-format (0x0210006100

10001E0100000500A80102)

Aug 2 17:09:58.491: Se0/1:0 IPCP: O CONFREJ [ACKrcvd] id 31 len 20

Aug 2 17:09:58.491: Se0/1:0 IPCP: CompressType RTP iphc-format (0x0210006100

10001E0100000500A80102)

Aug 2 17:09:58.531: Se0/1:0 IPCP: TIMEout: State ACKrcvd

Aug 2 17:09:58.531: Se0/1:0 IPCP: O CONFREQ [ACKrcvd] id 190 len 10

Aug 2 17:09:58.531: Se0/1:0 IPCP: Address 192.168.1.2 (0x0306C0A80102)

Aug 2 17:09:58.615: Se0/1:0 IPCP: I CONFACK [REQsent] id 190 len 10

Aug 2 17:09:58.615: Se0/1:0 IPCP: Address 192.168.1.2 (0x0306C0A80102)

Aug 2 17:10:00.491: Se0/1:0 IPCP: I CONFREQ [ACKrcvd] id 32 len 26

Aug 2 17:10:00.491: Se0/1:0 IPCP: Address 192.168.1.1 (0x0306C0A80101)

Aug 2 17:10:00.491: Se0/1:0 IPCP: CompressType RTP iphc-format (0x0210006100

10001E0100000500A80102)

Aug 2 17:10:00.491: Se0/1:0 IPCP: O CONFREJ [ACKrcvd] id 32 len 20

Aug 2 17:10:00.491: Se0/1:0 IPCP: CompressType RTP iphc-format (0x0210006100

10001E0100000500A80102)

which side is requesting the ip rtp header-compression ?!!!

[Richard Burts]

Tam

It looks to me like your router is now trying to do compression. Would you be able to reboot your router and then post the output of the config of the interface and the output of show interface?

HTH

Rick