Please help :) The network topology is: ADSL CPE (Cisco 2800) +===[PPPoE]===+ LAC (Telco's equipment) +===[L2TP]===+ LNS (Cisco 7513) The setup is for aggregating multiple PPPoE DSL lines with PPP. Using the Cisco 7513 as the LNS, the setup works up to 15 MLPPP bundles and with Cisco 7200-NPE400 only works up to 5 MLPPP bundles. After that, additional MLPPP bundle attempting to connect won't be able to complete IPCP phrase--the L2TP tunnels are created, each individual PPP link members are up, and the MLPPP bundle is created, just cannot finish the IP "handshake" part of the IPCP phrase. In fact, even a normal PPP (without Multilink) session won't be able to complete the IPCP phrase as long as there are 15 active working MLPPP bundle is on. I have search through Cisco's website to see if there is any documented limitation/restriction on the number of bundles the 7513 can support. The closest thing I can find is an reference to a 7500 w/ VIP4-80 can only support a limited number of T1 MLPPP bundles ( http://www.cisco.com/en/US/docs/ios/12_0t/12_0t3/feature/guide/multippp.html... ). Cisco 7513 spec: Cisco IOS Software, RSP Software (RSP-JSV-M), Version 12.4(21), RELEASE SOFTWARE (fc1) Cisco RSP8 (R7000) processor with 262144K/8216K bytes of memory. R7000 CPU at 250MHz, Implementation 39, Rev 2.1, 256KB L2, 2048KB L3 Cache Last reset from power-on Chassis Interface. 1 FEIP2 controller (2 FastEthernet). 2 FastEthernet interfaces 2043K bytes of NVRAM. 62720K bytes of ATA PCMCIA card at slot 0 (Sector size 512 bytes). 16384K bytes of Flash internal SIMM (Sector size 256K). Cisc 2800 spec: Cisco IOS Software, 2800 Software (C2800NM-ADVIPSERVICESK9-M), Version 12.4(15)T3, RELEASE SOFTWARE (fc1) Cisco 2811 (revision 53.51) with 247808K/14336K bytes of memory. Processor board ID FTX0945A4WJ 2 FastEthernet interfaces 3 ATM interfaces 1 Virtual Private Network (VPN) Module DRAM configuration is 64 bits wide with parity enabled. 239K bytes of non-volatile configuration memory. 62720K bytes of ATA CompactFlash (Read/Write) ----------- Relevant CPE config: ----------------- interface ATM0/0/0 no ip address no atm ilmi-keepalive dsl operating-mode auto pvc 0/33 tx-ring-limit 3 vc-hold-queue 80 pppoe-client dial-pool-number 1 ! ! interface ATM0/1/0 no ip address no atm ilmi-keepalive dsl operating-mode auto pvc 0/33 tx-ring-limit 3 vc-hold-queue 80 pppoe-client dial-pool-number 1 ! ! interface Dialer1 mtu 1486 ip address x.x.x.1 255.255.255.0 encapsulation ppp dialer pool 1 no keepalive no fair-queue no cdp enable ppp chap hostname abc@smarttadsl.com ppp chap password highlysecretive ppp pap sent-username vaamadsl@smarttadsl.com password highlysecretive ppp link reorders ppp multilink ppp multilink fragment disable ! ip route 0.0.0.0 0.0.0.0 Dialer1 ----------- Relevant LNS config: ----------------- aaa authentication ppp default group radius aaa accounting network default start-stop group radius vpdn enable ! vpdn-group 1 ! Default L2TP VPDN group accept-dialin protocol l2tp virtual-template 1 lcp renegotiation always l2tp tunnel password faketunnelpass ip mtu adjust interface FastEthernet8/1/0 description Facing-LAC ip address y.y.y.5 255.255.255.252 ip tcp adjust-mss 1446 full-duplex fair-queue ! interface Virtual-Template1 ip address x.x.x.254 255.255.255.0 no peer default ip address no keepalive ppp mtu adaptive ppp authentication pap ppp link reorders ppp multilink ppp multilink fragment disable ! Sarpreet Basi Knowledge Computers sar@knowledgecomputers.net