Add to [modules] section log_file

In section [log] set level=5

then restart accel-ppp

ok

after restart look in to logs

tail -n 100 /var/log/accel-ppp/emerg.log

define on top of list

[modules]
log_file

And then loog to general log file

tail -n 100 /var/log/accel-ppp/accel-ppp.log

[root@VM-0-13-centos build]# tail -n 100 /var/log/accel-ppp/emerg.log
radius: no dm_coa_secret specified, DM/CoA disabled...
radius: no dm_coa_secret specified, DM/CoA disabled...
radius: no dm_coa_secret specified, DM/CoA disabled...
radius: no dm_coa_secret specified, DM/CoA disabled...
radius: no dm_coa_secret specified, DM/CoA disabled...
radius: no dm_coa_secret specified, DM/CoA disabled...
[root@VM-0-13-centos build]# tail -n 100 /var/log/accel-ppp/accel-ppp.log
[2020-09-15 08:03:40]:  warn: failed to load pptp kernel module
[2020-09-15 08:04:45]:  warn: pptp: IP is out of client-ip-range, droping connection...
[2020-09-15 08:04:47]:  warn: pptp: IP is out of client-ip-range, droping connection...
[2020-09-15 08:05:25]:  warn: pptp: IP is out of client-ip-range, droping connection...
[2020-09-15 08:07:12]:  warn: pptp: IP is out of client-ip-range, droping connection...
[2020-09-15 08:07:19]:  warn: pptp: IP is out of client-ip-range, droping connection...
[2020-09-15 08:12:50]:  info: terminate, sig = 15
[2020-09-15 08:13:12]:  warn: pptp: IP is out of client-ip-range, droping connection...
[2020-09-15 08:13:16]:  warn: pptp: IP is out of client-ip-range, droping connection...
[2020-09-15 08:13:45]:  info: terminate, sig = 15
[2020-09-15 08:13:53]:  warn: pptp: IP is out of client-ip-range, droping connection...
[2020-09-15 08:13:56]:  warn: pptp: IP is out of client-ip-range, droping connection...
[2020-09-15 08:14:03]:  warn: pptp: IP is out of client-ip-range, droping connection...
[2020-09-15 08:14:04]:  warn: pptp: IP is out of client-ip-range, droping connection...
[2020-09-15 08:53:42]:  warn: pptp: IP is out of client-ip-range, droping connection...
[2020-09-15 09:16:29]:  warn: pptp: IP is out of client-ip-range, droping connection...
[2020-09-15 11:11:30]:  warn: pptp: IP is out of client-ip-range, droping connection...
[2020-09-15 13:36:53]:  warn: pptp: IP is out of client-ip-range, droping connection...
[2020-09-15 14:43:07]:  info: terminate, sig = 15
[2020-09-15 14:43:54]:  warn: pptp: IP is out of client-ip-range, droping connection...
[2020-09-15 14:43:56]:  warn: pptp: IP is out of client-ip-range, droping connection...
[2020-09-15 15:05:09]:  warn: pptp: iprange module disabled, improper IP configuration of PPP interfaces may cause kernel soft lockup
[2020-09-15 15:05:09]: error: sstp: ssl-pemfile error: error:02001002:system library:fopen:No such file or directory
[2020-09-15 15:05:09]:  info: sstp: SSL/TLS support disabled, PROXY support disabled
[2020-09-15 15:05:09]:  warn: sstp: iprange module disabled, improper IP configuration of PPP interfaces may cause kernel soft lockup
[2020-09-15 15:05:09]:  warn: l2tp: iprange module disabled, improper IP configuration of PPP interfaces may cause kernel soft lockup
[2020-09-15 15:05:09]:  info: send [RADIUS(1) Accounting-Request id=1 <Acct-Status-Type Accounting-On> <NAS-Identifier "hh">]
[2020-09-15 15:05:12]:  info: send [RADIUS(1) Accounting-Request id=1 <Acct-Status-Type Accounting-On> <NAS-Identifier "hh">]
[2020-09-15 15:05:15]:  info: send [RADIUS(1) Accounting-Request id=1 <Acct-Status-Type Accounting-On> <NAS-Identifier "hh">]
[2020-09-15 15:05:57]:  warn: pptp: iprange module disabled, improper IP configuration of PPP interfaces may cause kernel soft lockup
[2020-09-15 15:05:57]: error: sstp: ssl-pemfile error: error:02001002:system library:fopen:No such file or directory
[2020-09-15 15:05:57]:  info: sstp: SSL/TLS support disabled, PROXY support disabled
[2020-09-15 15:05:57]:  warn: sstp: iprange module disabled, improper IP configuration of PPP interfaces may cause kernel soft lockup
[2020-09-15 15:05:57]:  warn: l2tp: iprange module disabled, improper IP configuration of PPP interfaces may cause kernel soft lockup
[2020-09-15 15:05:57]:  info: send [RADIUS(1) Accounting-Request id=1 <Acct-Status-Type Accounting-On> <NAS-Identifier "hh">]
[2020-09-15 15:06:00]:  info: send [RADIUS(1) Accounting-Request id=1 <Acct-Status-Type Accounting-On> <NAS-Identifier "hh">]
[2020-09-15 15:06:03]:  info: send [RADIUS(1) Accounting-Request id=1 <Acc

t-Status-Type Accounting-On> <NAS-Identifier "hh">]

Error and accel- ppp.log

show me

modinfo pptp

From logs we see that it should works

Hey, l2tp this is UDP

add u to your netstat command