Hi all,
I have some problems with my Cisco 1921 router when trying to forward UDP ports. There are 2 network interfaces:
- gi0/0 [connected to the internet]
- gi0/1 [connected to the private network]
The router is suposed to do NAT and to forward TCP port 80, TCP port 1720 and UDP port 1719. The TCP ports are forwarded corectly, the problem is on UDP - router replies with ICMP destination port unreachable when internet users try to reach the inside "server". Same configuration was verified on one Cisco 892 Router and no problem was found [UDP port was correctly redirected].
Here is the config:
!
version 15.1
service timestamps debug datetime msec
service timestamps log datetime msec
no service password-encryption
!
hostname R2-1921
!
boot-start-marker
boot system usbflash0 c1900-universalk9-mz.SPA.151-2.T2.bin
boot-end-marker
!
!
!
no aaa new-model
!
no ipv6 cef
ip source-route
ip cef
!
!
!
!
!
no ip domain lookup
multilink bundle-name authenticated
!
!
!
!
!
interface GigabitEthernet0/0
ip address 195.90.xxx.yyy 255.255.255.128
ip nat enable
duplex auto
speed auto
!
interface GigabitEthernet0/1
ip address 192.168.1.1 255.255.255.0
ip nat enable
duplex auto
speed auto
!
ip forward-protocol nd
!
no ip http server
no ip http secure-server
!
ip nat source list 10 interface GigabitEthernet0/0 overload
ip nat source static tcp 192.168.1.205 80 interface GigabitEthernet0/0 80
ip nat source static udp 192.168.1.205 1719 interface GigabitEthernet0/0 1719
ip nat source static tcp 192.168.1.205 1720 interface GigabitEthernet0/0 1720
ip route 0.0.0.0 0.0.0.0 195.90.xxx.yyy
!
access-list 10 permit 192.168.1.0 0.0.0.255
!
!
!
control-plane
!
!
line con 0
line aux 0
line vty 0 4
login
transport input all
!
scheduler allocate 20000 1000
end
