vpn连接 错误734 ppp控制连接协议终止!请高手帮助

Plugin /usr/lib/pptpd/pptpd-logwtmp.so loaded.
pptpd-logwtmp: $Version$
pppd options in effect:
debug           # (from /etc/ppp/options.pptpd)
logfile /var/log/pptpd.log              # (from /etc/ppp/options.pptpd)
dump            # (from /etc/ppp/options.pptpd)
multilink               # (from /etc/ppp/options.pptpd)
plugin /usr/lib/pptpd/pptpd-logwtmp.so          # (from command line)
auth            # (from /etc/ppp/options.pptpd)
refuse-pap              # (from /etc/ppp/options.pptpd)
refuse-chap             # (from /etc/ppp/options.pptpd)
refuse-mschap           # (from /etc/ppp/options.pptpd)
refuse-mschap-v2                # (from /etc/ppp/options.pptpd)
refuse-eap              # (from /etc/ppp/options.pptpd)
name rh9vpn             # (from /etc/ppp/options.pptpd)
pptpd-original-ip 60.172.141.90         # (from command line)
115200          # (from command line)
lock            # (from /etc/ppp/options.pptpd)
local           # (from command line)
ipparam 60.172.141.90           # (from command line)
proxyarp                # (from /etc/ppp/options.pptpd)
60.172.141.93:192.168.1.230             # (from command line)
require-mppe            # (from /etc/ppp/options.pptpd)
"pptpd.log" 54L, 2952C                                        5,1           Top
Plugin /usr/lib/pptpd/pptpd-logwtmp.so loaded.
pptpd-logwtmp: $Version$
pppd options in effect:
debug           # (from /etc/ppp/options.pptpd)
logfile /var/log/pptpd.log              # (from /etc/ppp/options.pptpd)
dump            # (from /etc/ppp/options.pptpd)
multilink               # (from /etc/ppp/options.pptpd)
plugin /usr/lib/pptpd/pptpd-logwtmp.so          # (from command line)
auth            # (from /etc/ppp/options.pptpd)
refuse-pap              # (from /etc/ppp/options.pptpd)
refuse-chap             # (from /etc/ppp/options.pptpd)
refuse-mschap           # (from /etc/ppp/options.pptpd)
refuse-mschap-v2                # (from /etc/ppp/options.pptpd)
refuse-eap              # (from /etc/ppp/options.pptpd)
name rh9vpn             # (from /etc/ppp/options.pptpd)
pptpd-original-ip 60.172.141.90         # (from command line)
115200          # (from command line)
lock            # (from /etc/ppp/options.pptpd)
local           # (from command line)
ipparam 60.172.141.90           # (from command line)
proxyarp                # (from /etc/ppp/options.pptpd)
60.172.141.93:192.168.1.230             # (from command line)
require-mppe            # (from /etc/ppp/options.pptpd)
using channel 24
Starting negotiation on /dev/pts/1
sent [LCP ConfReq id=0x1 <asyncmap 0x0> <auth eap> <magic 0xe2dc1728> <pcomp> <accomp> <mrru 1500> <endpoint [MAC:00:e0:4c:82:16:21]>]
rcvd [LCP ConfReq id=0x0 <mru 1400> <magic 0x2ce85d97> <pcomp> <accomp> <callback CBCP>]
sent [LCP ConfRej id=0x0 <callback CBCP>]
rcvd [LCP ConfRej id=0x1 <mrru 1500> <endpoint [MAC:00:e0:4c:82:16:21]>]
sent [LCP ConfReq id=0x2 <asyncmap 0x0> <auth eap> <magic 0xe2dc1728> <pcomp> <accomp>]
rcvd [LCP ConfReq id=0x1 <mru 1400> <magic 0x2ce85d97> <pcomp> <accomp>]
sent [LCP ConfAck id=0x1 <mru 1400> <magic 0x2ce85d97> <pcomp> <accomp>]
rcvd [LCP ConfNak id=0x2 <auth chap MD5>]
sent [LCP ConfReq id=0x3 <asyncmap 0x0> <auth chap MD5> <magic 0xe2dc1728> <pcomp> <accomp>]
rcvd [LCP ConfAck id=0x3 <asyncmap 0x0> <auth chap MD5> <magic 0xe2dc1728> <pcomp> <accomp>]
sent [CHAP Challenge id=0xa6 <1a6a557cf3adf6f6d34ff362bd7bd729e7ee988624f1>, name = "rh9vpn"]
rcvd [LCP code=0xc id=0x2 2c e8 5d 97 4d 53 52 41 53 56 35 2e 31 30]
sent [LCP CodeRej id=0x4 0c 02 00 12 2c e8 5d 97 4d 53 52 41 53 56 35 2e 31 30]
rcvd [LCP code=0xc id=0x3 2c e8 5d 97 4d 53 52 41 53 2d 30 2d 4d 53 31 31 35 37 33 33]
sent [LCP CodeRej id=0x5 0c 03 00 18 2c e8 5d 97 4d 53 52 41 53 2d 30 2d 4d 53 31 31 35 37 33 33]
rcvd [CHAP Response id=0xa6 <1b39bff6b881204d373f78d90f34285a>, name = "a123"]
sent [CHAP Success id=0xa6 "Access granted"]
Using interface ppp0
MPPE required, but MS-CHAP[v2] auth not performed.
sent [LCP TermReq id=0x6 "MPPE required but not available"]
rcvd [CCP ConfReq id=0x4 <mppe +H -M -S -L -D +C>]
Discarded non-LCP packet when LCP not open
rcvd [IPCP ConfReq id=0x5 <addr 0.0.0.0> <ms-dns1 0.0.0.0> <ms-wins 0.0.0.0> <ms-dns3 0.0.0.0> <ms-wins 0.0.0.0>]
Discarded non-LCP packet when LCP not open
rcvd [LCP TermAck id=0x6 "MPPE required but not available"]
Connection terminated.
Connect time 0.1 minutes.
Sent 0 bytes, received 44 bytes.
tcflush failed: Input/output error

这个怎么解决!高手帮忙!