3825 IP NAT问题

xujf

一台3825，作为公司INTERNET的出口路由器，配置了IP NAT。现在经常会出现有些机器突然无法上网的现象，查看IP NAT转换表，发现路由器没有为这些机器创建新的IP转换条目，而另一些机器却是正常能出去。每次出现此类问题都需要做clea ip nat tr *就可以出去了，但过一段时间又会出现问题。机器的负载和NAT池条目都不大，怀疑是IOS问题，升级后还是如此，请各位大侠分析一下问题所在，谢谢。
version 12.4
service timestamps debug datetime msec
service timestamps log datetime msec
no service password-encryption
!
hostname Router
!
boot-start-marker
boot-end-marker
!
enable secret 5 $1$C25O$Vveedj0JAzStbOur/MXim/
!
no aaa new-model
!
resource policy
!
ip subnet-zero
ip cef
!
no ip dhcp use vrf connected
!
no ip domain lookup
no ip ips deny-action ips-interface
!
interface GigabitEthernet0/0
ip address 192.168.1.1 255.255.255.0
ip nat inside
ip virtual-reassembly
duplex auto
speed auto
media-type rj45
negotiation auto
!
interface GigabitEthernet0/1
ip address 218.69.31.9 255.255.255.252
ip nat outside
ip virtual-reassembly
duplex auto
speed auto
media-type rj45
negotiation auto
no cdp enable
!
ip classless
ip route 0.0.0.0 0.0.0.0 218.69.31.9
ip route 192.168.0.0 255.255.0.0 192.168.1.254
!
no ip http server
no ip http secure-server
ip nat translation tcp-timeout 3600
ip nat inside source list NAT interface GigabitEthernet0/1 overload
!
control-plane
!
line con 0
stopbits 1
line aux 0
stopbits 1
line vty 0 4
login
!
scheduler allocate 20000 1000
!
end

cnadl

try 12.3 mainline or 12.3T

it seems 12.4 got problem in nat