>На клиентах после подключения default gateway на 192.168.0.28? Маршрутизация включена? Правила firewall-а? 
>Клиент пингует компы из сети 193.168.0.0./24? John прав, такой опции -detach 
>нет. Есть nodetaсh. Откуда Вы только это берете? 
# ps ax|grep routed
17066 ?        Ss     0:00 /usr/sbin/routed -g -s
# cat /proc/sys/net/ipv4/ip_forward
1
файрволов нет! 
Да откуда я это взял??? ...
Так работало раньше, на старой машине, конфиги были перенесены. 
Сейчас возникла трабла вник глубже, сменил кой чего, но результат тотже!
У клиента вывод команды ipconfig:  
        IP Address. . . . . . . . . . . . : 193.168.0.29
        Subnet Mask . . . . . . . . . . . : 255.255.255.255
        Default Gateway . . . . . . . . . : 193.168.0.29
Похоже в этом и трабла! Но как ее исправить??????????????????????????
С клиента пинга нет! Проверял с WinXP, 
Что касается Win98 не поднялся даже ppp интерфейс логи ниже.
сейчас конфиги такие:
#/etc/ppp/options
#+++++++++++++++++++++++++
auth
asyncmap 0                                                                      
crtscts                                                                        
lock                                                                            
modem                                                                          
debug                                                                          
proxyarp                                                                        
login                                                                          
refuse-chap                                                                    
require-pap                                                                    
193.168.0.28:193.168.0.29
#++++++++++++++++++++++++++
# /etc/mgetty+sendfax/login.config
#============================
/AutoPPP/  -    a_ppp   /usr/sbin/pppd auth refuse-chap require-pap login debug
#==============================
# /etc/mgetty+sendfax/
# ------------------------------
debug 4                           
#fax-id                                                                         
                                                                                speed 57600 
port ttyS0                                                                      
  debug 4                                                                       
  data-only y
#-------------------------------
Вот логи mgetty при конекте клиента(Win98):06/29 17:07:59 yS1  waiting...
=============================================
06/29 17:08:59 yS1  wfr: waiting for ``RING''
06/29 17:08:59 yS1  wfr: waiting for ``RING''
06/29 17:09:04 yS1  wfr: waiting for ``RING''
06/29 17:09:09 yS1  send: ATA[0d]
06/29 17:09:09 yS1  waiting for ``CONNECT'' ** found **
06/29 17:09:27 yS1  send: 
06/29 17:09:27 yS1  waiting for ``_'' ** found **
06/29 17:09:31 ##### data dev=ttyS1, pid=17125, caller='none', conn='57600', nam
e='', cmd='/bin/login', user='/AutoPPP/'
--
06/29 17:10:05 yS1  mgetty: interim release 1.1.33-Apr10
06/29 17:10:05 yS1  check for lockfiles
06/29 17:10:05 yS1  locking the line
06/29 17:10:05 yS1  can't get group 'modem': No such process
06/29 17:10:06 yS1  lowering DTR to reset Modem
06/29 17:10:06 yS1  send: \dATQ0V1H0[0d]
06/29 17:10:07 yS1  waiting for ``OK''
06/29 17:10:07 yS1  found action string: ``NO CARRIER''
06/29 17:10:07 yS1  init chat failed, exiting...: Invalid argument
06/29 17:10:07 ##### failed in mg_init_data, dev=ttyS1, pid=17128
--
06/29 17:10:07 yS1  mgetty: interim release 1.1.33-Apr10
06/29 17:10:07 yS1  check for lockfiles
06/29 17:10:07 yS1  locking the line
06/29 17:10:07 yS1  can't get group 'modem': No such file or directory
06/29 17:10:08 yS1  lowering DTR to reset Modem
06/29 17:10:08 yS1  send: \dATQ0V1H0[0d]
06/29 17:10:09 yS1  waiting for ``OK'' ** found **
06/29 17:10:09 yS1  send: ATS0=0[0d]
06/29 17:10:09 yS1  waiting for ``OK'' ** found **
06/29 17:10:09 yS1  waiting...
===================================================
А вот тот же клиент запускает терминал и логинится по нему
+++++++++++++++++++++++===================================
--
06/29 17:27:58 yS1  mgetty: interim release 1.1.33-Apr10
06/29 17:27:58 yS1  check for lockfiles
06/29 17:27:58 yS1  locking the line
06/29 17:27:58 yS1  can't get group 'modem': No such file or directory
06/29 17:27:58 yS1  lowering DTR to reset Modem
06/29 17:27:59 yS1  send: \dATQ0V1H0[0d]
06/29 17:27:59 yS1  waiting for ``OK'' ** found **
06/29 17:28:00 yS1  send: ATS0=0[0d]
06/29 17:28:00 yS1  waiting for ``OK'' ** found **
06/29 17:28:00 yS1  waiting...
06/29 17:28:12 yS1  wfr: waiting for ``RING''
06/29 17:28:12 yS1  wfr: waiting for ``RING''
06/29 17:28:17 yS1  wfr: waiting for ``RING''
06/29 17:28:23 yS1  send: ATA[0d]
06/29 17:28:23 yS1  waiting for ``CONNECT'' ** found **
06/29 17:28:41 yS1  send: 
06/29 17:28:41 yS1  waiting for ``_'' ** found **
06/29 17:28:50 ##### data dev=ttyS1, pid=17342, caller='none', conn='57600', nam
e='', cmd='/bin/login', user='pppsorok'
--
06/29 17:28:56 yS1  mgetty: interim release 1.1.33-Apr10
06/29 17:28:56 yS1  check for lockfiles
06/29 17:28:56 yS1  locking the line
06/29 17:28:56 yS1  can't get group 'modem': No such process
06/29 17:28:56 yS1  lowering DTR to reset Modem
06/29 17:28:57 yS1  send: \dATQ0V1H0[0d]
06/29 17:28:57 yS1  waiting for ``OK''
06/29 17:28:58 yS1  found action string: ``NO CARRIER''
06/29 17:28:58 yS1  init chat failed, exiting...: Invalid argument
06/29 17:28:58 ##### failed in mg_init_data, dev=ttyS1, pid=17375
--
06/29 17:28:58 yS1  mgetty: interim release 1.1.33-Apr10
06/29 17:28:58 yS1  check for lockfiles
06/29 17:28:58 yS1  locking the line
06/29 17:28:58 yS1  can't get group 'modem': No such file or directory
06/29 17:28:58 yS1  lowering DTR to reset Modem
06/29 17:28:59 yS1  send: \dATQ0V1H0[0d]
06/29 17:28:59 yS1  waiting for ``OK'' ** found **
06/29 17:29:00 yS1  send: ATS0=0[0d]
06/29 17:29:00 yS1  waiting for ``OK'' ** found **
06/29 17:29:00 yS1  waiting...
06/29 17:29:12 yS1  wfr: waiting for ``RING''
06/29 17:29:12 yS1  wfr: waiting for ``RING''
06/29 17:29:22 yS1  mdm_read_byte: read returned -1: Interrupted system call
06/29 17:29:22 yS1  wfr: timeout waiting for RING
06/29 17:29:22 ##### phone stopped ringing (rings=1, dev=ttyS1, pid=17376, calle
r='none')
06/29 17:29:23 yS1  waiting...
++++++++++++++++++++++++==============================
причем в последнем случае shell-ом ему прописан pppd
В обоих случаях интерфейс ppp не поднялся