У моих пользователей локальной сети последнее время постоянно рвется связь pppoe, причем в логах ничего криминального не удается заметить. Вот примеры:

[root@srv enk]# grep 15201 /var/log/messages
Apr 26 16:19:36 srv pppoe-server[15201]: Session 183 created for client 34:08:04:29:b9:c9 (10.67.15.183) on eth0.1031 using Service-Name ''
Apr 26 16:19:36 srv pppd[15201]: Plugin rp-pppoe.so loaded.
Apr 26 16:19:36 srv pppd[15201]: RP-PPPoE plugin version 3.3 compiled against pppd 2.4.4
Apr 26 16:19:36 srv pppd[15201]: Plugin radius.so loaded.
Apr 26 16:19:36 srv pppd[15201]: RADIUS plugin initialized.
Apr 26 16:19:36 srv pppd[15201]: Plugin radattr.so loaded.
Apr 26 16:19:36 srv pppd[15201]: RADATTR plugin initialized.
Apr 26 16:19:36 srv pppd[15201]: pppd 2.4.4 started by root, uid 0
Apr 26 16:19:36 srv pppd[15201]: Using interface ppp40
Apr 26 16:19:36 srv pppd[15201]: Connect: ppp40 <--> /dev/pts/40
Apr 26 16:19:38 srv pppd[15201]: Cannot determine ethernet address for proxy ARP
Apr 26 16:19:38 srv pppd[15201]: local  IP address 10.0.0.1
Apr 26 16:19:38 srv pppd[15201]: remote IP address 213.135.79.194
Apr 26 16:53:35 srv pppd[15201]: LCP terminated by peer (^KM-`^VM-^C^@<M-Mt^@^@^@^@)
Apr 26 16:53:35 srv pppd[15201]: Connect time 34.0 minutes.
Apr 26 16:53:35 srv pppd[15201]: Sent 6616871 bytes, received 1005373 bytes.
Apr 26 16:53:38 srv pppd[15201]: Connection terminated.
Apr 26 16:53:38 srv pppd[15201]: Modem hangup
Apr 26 16:53:38 srv pppd[15201]: Exit.
[root@srv enk]# grep 15074 /var/log/messages
Apr 26 16:05:25 srv pppoe-server[15074]: Session 180 created for client 00:1c:c0:29:df:94 (10.67.15.180) on eth0.1100 using Service-Name ''
Apr 26 16:05:25 srv pppd[15074]: Plugin rp-pppoe.so loaded.
Apr 26 16:05:25 srv pppd[15074]: RP-PPPoE plugin version 3.3 compiled against pppd 2.4.4
Apr 26 16:05:25 srv pppd[15074]: Plugin radius.so loaded.
Apr 26 16:05:25 srv pppd[15074]: RADIUS plugin initialized.
Apr 26 16:05:25 srv pppd[15074]: Plugin radattr.so loaded.
Apr 26 16:05:25 srv pppd[15074]: RADATTR plugin initialized.
Apr 26 16:05:26 srv pppd[15074]: pppd 2.4.4 started by root, uid 0
Apr 26 16:05:26 srv pppd[15074]: Using interface ppp0
Apr 26 16:05:26 srv pppd[15074]: Connect: ppp0 <--> /dev/pts/0
Apr 26 16:05:28 srv pppd[15074]: Cannot determine ethernet address for proxy ARP
Apr 26 16:05:28 srv pppd[15074]: local  IP address 10.0.0.1
Apr 26 16:05:28 srv pppd[15074]: remote IP address 213.135.79.185
Apr 26 16:49:28 srv pppd[15074]: LCP terminated by peer (WM-X`~^@<M-Mt^@^@^@^@)
Apr 26 16:49:28 srv pppd[15074]: Connect time 44.0 minutes.
Apr 26 16:49:28 srv pppd[15074]: Sent 52436495 bytes, received 3345292 bytes.
Apr 26 16:49:28 srv pppd[15074]: Terminating on signal 15
Apr 26 16:49:31 srv pppd[15074]: Connection terminated.
Apr 26 16:49:31 srv pppd[15074]: Modem hangup
Apr 26 16:49:31 srv pppd[15074]: Exit.

Иногда связь держится час, полчаса, а то и четверть часа.
Связь рвется всегда в разное время, причем связь при этом стабильная.

Также в логах часто видны сообщения вида, например, два подряд:

LCP terminated by peer (*Ri*^@<M-Mt^@^@^@^@)
Connect time 153.1 minutes.
Sent 301217426 bytes, received 9917087 bytes.
Connection terminated.
Modem hangup
pppoe: read (asyncReadFromPPP): Session 108: Input/output error
LCP terminated by peer (^\M-<gM-^M^@<M-Mt^@^@^@^@)
Connect time 21.1 minutes.
Sent 41173902 bytes, received 1382137 bytes.
Terminating on signal 15
Connection terminated.
Modem hangup
pppoe: read (asyncReadFromPPP): Session 193: Input/output error

В качестве дистрибутива для BRAS используется CentOS.

cat /proc/version
Linux version 2.6.18-274.18.1.el5PAE (mockbuild@builder10.centos.org) (gcc version 4.1.2 20080704 (Red Hat 4.1.2-51)) #1 SMP Thu Feb 9 13:25:50 EST 2012

/sbin/pppoe -V
Roaring Penguin PPPoE Version 3.5

Настройки pppoe:

# PPP options for the PPPoE server
# LIC: GPL
#refuse-pap
require-mschap-v2
require-chap
#require-mppe-128
#refuse-mppe
proxyarp
nologfd
login
lcp-echo-interval 10
lcp-echo-failure 6
mtu 1492
mru 1492
logfile /var/log/pppd.log
ms-dns 8.8.8.8
nobsdcomp
noccp
noendpoint
noipdefault
noipx
noipv6
novj
novjccomp
receive-all
plugin rp-pppoe.so
plugin radius.so
plugin radattr.so

Помогите советом, пожалуйста, куда копать, как исправить. Пользователи жалуются и могут сбежать ...