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TFTP causing network disconnect

J_Rega
Level 1
Level 1

Have tried solarwinds and tftp32, everytime I establish a tftp session with a switch on my network it terminates the connection between the tftp server and the switch, and by terminate I mean the devices will no longer communicate at all, the only way to restore the connection is to cycle the switch. If I send a 1kb file, it successfully sends and the connection fails approx 25 seconds later. If I send a large file, the connection drops during the transfer, again, about 30 seconds into the transfer. I will be able to ping anything from the server and the switch, except for each other. If I bring ports down and back up it still fails. The goal is to use TFTP to transfer IOS files. I understand there are various methods of transferring files but I would love to know what is causing this. Lastly, if I copy run tftp I have no issues, just copying from tftp to flash:

4 Replies 4

balaji.bandi
Hall of Fame
Hall of Fame

I would appreciate giving more information - what is the device model, what IOS it running, show us your config.

 

where is your TFTP Server, what is the IP address of TFTP ? where is this connected ( directly to this switch or to any other switch in the network)

BB

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Here are the specifics about the last switch I tried to update: The device is an IE2000 with IOS 15.0.2 EA1 loaded. The TFTP server IP is 10.100.10.200/21 on VLAN 2  and the switch is 10.100.70.1/23 on VLAN 3. The TFTP server is connected to an access port on a 2960x which has a trunk port to the IE2000. We use a 3750 for inter-vlan routing. 

 

I am no longer at work so the config file will have to wait until tomorrow.

Thank you for the input, how is these device connected?

 

3750 and 2960 and IE ? (small diagram will helpfull) along with your config.

BB

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We figured it out, well, how to make it work anyway.

 

The system was configured differently than reported (it's a remote site), specifically:

The TFTP server was on the 10.100.10.200/21 VLAN 2 with a gateway of 10.100.14.254.

The switch was 10.100.15.1/24 on VLAN 3 with a gateway of 10.100.15.254.

 

There was a permanent route on the TFTP server pointing 10.110.15 traffic through the 10.100.15 network so connecting via ssh was no issue at all, but, as we attempted to TFTP we would loose connectivity as discussed above.

 

We assigned an IP address to the VLAN 2 interface on the device we were configuring in the 10.100.10.X/21 address range and were able to TFTP without an issue. 

 

I do not know why VLAN 3's address space was sandwiched into VLAN 2's, but we are remedying that. Regardless, any chance someone out there has any insight as to why in the "not ideal" IP configuration the connection was terminated? It almost seems like the IP route was deconstructed and the devices no longer knew how to get to each other, but I can not prove that.

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