ISDN & Keepalives

[Pantman]

I am having difficulty downloading using an FTP client through my Cisco 1600 series router.
I have set up a dialer profile associated to the Bri interface with network address translation and an export to my privately addressed mail server on port 25.
Any FTP session is timing out at the specified dialer idle-timeout setting. I have two questions:
Why is FTP traffic not keeping the connection up?
Can I specify a 'keepalive' setting on the FTP ports by some manner?

Thanks for any help

 

[munsonbrown]

Honestly, if the only thing failing is FTP, it could be a bug, however if you could post your config here, we would have a better shot at helping you out.

 

[Pantman]

Please find below my config- any help greatly appreciated

Using 1672 out of 7506 bytes
!
version 12.0
service timestamps debug uptime
service timestamps log uptime
no service password-encryption
!
hostname edinburgh-shop
!
enable secret
!
!
!
!
!
ip subnet-zero
no ip domain-lookup
!
isdn switch-type basic-net3
isdn voice-call-failure 0
!
!
!
interface Ethernet0
description connected to EthernetLAN
ip address 192.168.1.254 255.255.255.0
no ip directed-broadcast
ip nat inside
!
interface Serial0
description connected to UnknownDevice
ip address 192.168.100.1 255.255.255.0
no ip directed-broadcast
no fair-queue
!
interface BRI0
description connected to Internet
no ip address
no ip directed-broadcast
ip nat outside
encapsulation ppp
dialer rotary-group 1
isdn switch-type basic-net3
no cdp enable
!
interface Dialer1
description connected to Internet
ip address 195.157.161.40 255.255.255.0
no ip directed-broadcast
ip nat outside
encapsulation ppp
no ip split-horizon
dialer in-band
dialer string 08451170500
dialer hold-queue 10
dialer-group 1
no cdp enable
ppp authentication pap chap callin
ppp pap sent-username dlan1294 password 7 14130004060B2C
!
router rip
network 192.168.1.0
network 192.168.100.0
!
ip nat inside source list 5 interface Dialer1 overload
ip nat inside source static tcp 192.168.1.249 25 195.157.161.40 25 extendable
ip classless
ip route 0.0.0.0 0.0.0.0 Dialer1
no ip http server
!
access-list 5 permit 192.168.1.0 0.0.0.255
dialer-list 1 protocol ip permit
snmp-server engineID local 000000090200000142063F01
snmp-server community public RO
!
line con 0
exec-timeout 0 0
password cmaker
login
transport input none
line vty 0 4
password cmaker
login
!
end

 

[munsonbrown]

The config looks good to me. If I understand your problem correctly, you start an ftp download, but the router doesn't find this traffic "interesting" so when the idle-timeout is reached, the call is disconnected. This is not the case for other type of traffic (web browsing, pings, etc.). I'm also assuming that you are initiating the ftp traffic from the inside, and that the download begins. If this is not the case, but rather the download stops due to a problem with the server or connecting to the server, than the problem may be that no traffic is actually being passed. To verify you connection to the FTP server, type show ip nat translation and look for you connecting to the server on port 21 (ftp). Also, you might want to play with some of the debug ip tcp commands.

If you are certain the traffic is passing, the dialer-list should be keeping the connection up. Call Cisco. They should be aware of the bug and offer you an upgrade to a known good version.

 

[jroysdon]

I don't see any idle-timeout configured. The syntax is:

dialer idle-timeout 240

(4 minutes, as it is specified in seconds)

 

[Pantman]

I know there's no timeout specified- however the default is 120seconds and seems to work fine. Web and SMTP traffic is working fine it just times out while FTPing

Thanks