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New Member

MLPP for 2 async interfaces dialing to ISP.

Hi All,

I am trying to bundle two PSTN lines via MLPP for increasing the bandwidth from my ISP for internet.

Both the lines dial get connected but no MLPP channel is formed.

Can someone suggest whether the problem lies in the configuration of my router or any other alternate configuration to accomplish the task.



Cisco Employee

Re: MLPP for 2 async interfaces dialing to ISP.

Looking on the config, i don't see "ppp multilink" configured under the interface serial2 and 3. So is the reason the multilink is not negotiated during LCP with ISP. So add following config under the interface serial 2 and serial 3

ppp authentication chap

ppp multilink

After that it should work ok. You can visit following url for config reference and troubleshooting.

With that config change, if it still doesn't work, Ask the ISP and see if they supports multilink PPP" connection using Async. I can see following from debug

Se2 LCP: I CONFREJ [REQsent] id 3 len 8

Se2 LCP: MRRU 1524 (0x110405F4)

MRRU for 1524 was rejected by isp. So they may not be supporting mutlilink ppp.

New Member

Re: MLPP for 2 async interfaces dialing to ISP.

thanks tejal for ur reply.

I did hve the mlpp command configured on the two interfaces but the problem yet exists.

As u mentioned , the isp itself is not supporting mlpp.

Can u suggest an alternate configuration to increase the bandwidth ??? Can load sharing be configured to achieve the same results ie increase the bandwidth ?

thanks & rgds


Cisco Employee

Re: MLPP for 2 async interfaces dialing to ISP.

Not really...Multilink ppp buys you a great feature of "fragmentation". So PPP packet will be fragmented and will be sent on each link of a multilink member.

Since we are talking about 2 individual point to point link (no mlppp), router already has two host routes to isp (/32 mask) for same destination so load balance will take place but no fragmentation. Sometimes routing may not work fine in that case.

So the best option is to have isp allow multilink ppp.

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