MSR3600配置L2PT VPN的问题

用模拟器做L2TP-AUTO-client ，配置完成之后，ppp协商成功，LAC侧能获取到IP地址，隧道也成功建立。 

在隧道两侧启用RIP之后，LNS能收到LAC侧的rip路由，但是lac侧收不到LNS的rip路由。附配置及拓扑。。如下

LNS的配置：

[LNS] local-user vpnuser class network

[LNS-luser-network-pc] password simple hello

[LNS-luser-network-pc] service-type ppp

[LNS-luser-network-pc] quit

[LNS]  ip pool 1 192.168.1.100 192.168.1.200 

[LNS] interface virtual-template 1

[LNS-Virtual-Template1] ip address 192.168.1.1 255.255.255.0

[LNS-Virtual-Template1] ppp authentication-mode pap

[LNS-Virtual-Template1] remote address pool 1

[LNS-Virtual-Template1] rip 1 enable 

[LNS-Virtual-Template1] quit

[LNS] domain system

[LNS-isp-system] authentication ppp local

[LNS-isp-system] quit

[LNS] l2tp enable

[LNS] l2tp-group 1 mode lns

[LNS-l2tp1] tunnel name lns

[LNS-l2tp1] tunnel authentication

[LNS-l2tp1] tunnel password simple 123

[LNS-l2tp1] allow l2tp virtual-template 1 remote lac

[LNS] rip 1

 [LNS-rip-1] version 2

 [LNS-rip-1] undo sum

 [LNS-rip-1] network 192.168.1.0 0.0.0.255

 [LNS-rip-1] network 10.10.10.1 0.0.0.255

LAC配置：

[LAC] l2tp enable

[LAC] l2tp-group 1 mode lac

[LAC-l2tp1] tunnel name lac

[LAC-l2tp1] lns-ip 3.3.3.2

[LAC-l2tp1] tunnel authentication

[LAC-l2tp1] tunnel password simple  123

[LAC-l2tp1] quit 

[LAC] interface Virtual-PPP 1

[LAC-Virtual-PPP1] ip address ppp-negotiate

[LAC-Virtual-PPP1] ppp pap local-user vpnuser password simple hello

[LAC-Virtual-PPP1] l2tp-auto-client l2tp-group 1

[LAC-Virtual-PPP1] rip 1 enable

[Lac] rip 1

 [ Lac  -rip-1] version 2

 [Lac-rip-1] undo sum

 [Lac-rip-1] network 192.168.1.0 0.0.0.255

 [Lac-rip-1] network 172.31.1.1 0.0.0.255

请大佬解答？