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HELP! Multilink PPP w/3 T1s and a seperate 4th T1

lightfish1
Level 1
Level 1

I've got a Cisco 3640 with 128M/32M RAM. There are 2x NM-2FE2W and 4x

WIC-1DSU-T1 cards installed. The configurations for the interfaces are

below. I have 4 point-to-point T1s coming into this router. 3 T1s are

coming from another 3640 at one office (A) and the other T1 is coming

from a 2514 at another office (B). I control all 3 routers.

I've been using Multilink PPP to give my users a 3M pipe over 2 of the

T1s at office A. I had a 3rd T1 installed in order to bump it up to

4.5M. Office B is serviced by a the single (fourth) T1.

Before the new T1 was installed everything worked fine (2 T1s using

MLPPP to office A and 1 T1 to office B). Now, with all 4 lines running,

the 3rd MLPPP line won't work (see 'sho int' and 'sho service-module'

below) but the original 3 lines work fine.

Now here's where it gets strange. If I remove the card servicing the T1

to office B and boot up the router, all 3 interfaces come up and MLPPP

works great, providing a 4.5M pipe. Once I shut down the router and

reinsert the card for office B, the 3rd MLPPP lines goes down again. I

tried swapping the office B card/cable with the card(s)/cable(s) from

the 1st and 2nd MLPPP lines and get the exact same results. Same goes

for the card/cable servicing the 3rd MLPPP line.

Am I missing a configuration step? I'm at a loss.

Again, I've swapped WIC cards, NM cards, and cables between all

interfaces and they all work. I've also tried different slots for the

NMs. No difference.

Help! TIA

Rich

_____________________________

interface Multilink1

ip address A.B.C.D 255.255.255.252

ip route-cache flow

fair-queue 64 16 0

no cdp enable

ppp multilink

ppp multilink fragment delay 10

ppp multilink interleave

ppp multilink group 1

!

interface MFR1

no ip address

!

interface FastEthernet0/0

ip address E.F.G.H 255.255.255.240

ip route-cache flow

speed 100

full-duplex

!

interface Serial0/0

bandwidth 1536

no ip address

encapsulation ppp

fair-queue

ppp multilink

ppp multilink group 1

!

interface FastEthernet0/1

ip address I.J.K.L 255.255.255.224

speed 100

full-duplex

!

interface Serial0/1

bandwidth 1536

no ip address

encapsulation ppp

fair-queue

ppp multilink

ppp multilink group 1

!

interface FastEthernet1/0

no ip address

speed 100

full-duplex

!

interface Serial1/0

bandwidth 1536

no ip address

encapsulation ppp

fair-queue

ppp multilink

ppp multilink group 1

!

interface FastEthernet1/1

ip address M.N.O.P 255.255.255.252 secondary

ip address Q.R.S.T 255.255.255.128 secondary

ip address U.V.W.X 255.255.255.248

speed 100

full-duplex

!

interface Serial1/1

ip address Y.Z.A.B 255.255.255.252

no ip mroute-cache

autodetect encapsulation ppp

3 Replies 3

jackyoung
Level 6
Level 6

Really don't find any problem on the hardware or software issue. Did you try to insert NM2FE-2W at slot 0 & 2 or solt 1 & 3 ?

Moreover, did you confirm the linecode is correct that there are may line code volidations.

Hope this helps.

Thanks for the reply!

The framing is ESF on both ends and line code is B8ZS. Like I said above, it's weird because it works if I remove the 4th card.

I'll try the cards in different slots.

Rich

Thanks. I can find the linecode and framing from your capture too. Wait for your result.

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