router backup config to tftp server shows 0 kbytes

[Robin Thomas]

Hello, Quite recently we changed our tftp server for voice g/w backups to another server running win 7. We are using tftp32 as tftp client and a rule has been added under windows firewall. Files are backingup to the new server but for most of the gateways the size of that files are 0kb......but some gateways are backingup correctly.

We have tested in around 40 gateways....in that only 4 or 5 gateways are backing up correctly. Any comments ?

Regards/ Robin

[acampbell]

Hi Robin

You need to pick a router/vgwy is not backing up.

The router by default will use the IP address nearest to the TFTPSERVER.

So the router could have say 4 addresses

!
loopback 0
desc ** ALWAYS UP FOR MANAGEMENT ETC ***
ip add 10.100.100.100 255.255.255.255
!
int fas 0/0
desc *** LAN TO CORE SW A ***
ip add 172.16.1.100 255.255.255.0
!
int fas 0/1
desc *** LAN TO CORE SW B ***
ip add 172.16.1.200 255.255.255.0
!
int ser 0/0/0
desc *** WAN LINK TO HQ BUILDING ***
ip add 192.168.100.254 255.255.255.252
!

Lets say the Ip route to the TFTPSERVER is via the SER 0/0/0 port to the HQ building.

The router will use IP address 192.168.100.254 as it source for TFTP transaction.

The TFTPSERVER may not be able to ping or IP route to 192.168.100.254 but can route/ping say
the loopback address 10.100.100.100

You would overcome this on the router by adding the following command in the global config:-

!
ip tftp source-interface loop 0
!

Have a look at what address you think you should be using to source you TFTP packets.
Make sure the TFTPSERVER can ping that address.
add the config line to suit and retest
 

Regards
Alex

[Parvesh Paliwal]

Need to elaborate:

''Lets say the Ip route to the TFTPSERVER is via the SER 0/0/0 port to the HQ building.

The router will use IP address 192.168.100.254 as it source for TFTP transaction.

The TFTPSERVER may not be able to ping or IP route to 192.168.100.254 but can route/ping say
the loopback address 10.100.100.100''

Well, it can be any of the interface which may or may not be reachable over the network. Try to confirm first and then come to a conclusion - whether it s a loopback or physical interface.

-

Parvesh

Please mark helpful posts.

[Robin Thomas]

Hello Gents,

Thanks for your response. it has been observed that all g/w's is backing up successfully to previous TFTP but only few of them is able to back up to new TFTP.

we are using an automated type of tftp copy to backup the configuration of routers in the network.

- When we copy files to 10.252.250.225  you get 0 kbyte for the files.

- 10.252.250.225  is pingable from the non-working scenario router.

-We tried to do a manual copy for a text file created on the rouer.

-The copy fails as a reason of a timeout.

-This points to a connectivity issue and not specific to a router or software version , which could be route issue , mis-configured access-list ,etc.

-We tested on the non-working scenario router to copy files to 10.251.64.3 and the copy was successful.

I did a traceroute from one of the g/w to both TFTP and i suspect a network path issue on the new TFTP. Please see the snapshot

Regards