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FTP Download Protocol Error

Level 1
Level 1


I am currently trying to upgrade my C4948s I successfully upgraded 5 units but one is giving me an issue. 

This is what I am doing:

Switch#config t
Enter configuration commands, one per line. End with CNTL/Z.
Switch(config)#int vlan 1
Switch(config-if)#ip add
Switch(config-if)#no shut
Switch(config)#ip ftp user bob
Switch(config)#ip ftp password password
00:08:38: %SYS-5-CONFIG_I: Configured from console by console
Switch#copy ftp: bootflash:
Address or name of remote host []?
Source filename []? cat4500-entservicesk9-mz.150-2.SG11.bin
Destination filename [cat4500-entservicesk9-mz.150-2.SG11.bin]?
%Error opening (Protocol error)

Any Ideas?

7 Replies 7



I assume the switch can ping the FTP server ? Do SCP and/or TFTP work ? The FTP server usually has some sort of log, what does that say ?


You might want to try and enter the line below as a whole instead of using the prompts:


switch#copy ftp://bob:password@ bootflash:


Do you have any access list on this device blocking ftp?

Richard Burts
Hall of Fame
Hall of Fame

The original post says that 5 units have been upgraded successfully. Can you verify that these units were using the same FTP server and were loading the same image file? If so it would eliminate possible issues of files in correct directory of FTP, permitting remote read access, etc. 


The switch is configured with an IP in network The address of the FTP server is in that range so we should be dealing with local access and would not have any issues about routing. Can you verify that the FTP server IP and mask also put it into that network? After you attempt the FTP would you do show arp and verify that your switch does have an entry for the FTP server address?


I agree that checking the logs of the FTP server might provide helpful information. Does the FTP server log indicate that it received the request from your switch? Does the log indicate any issue about responding to that request?







I followed the same method for each of the switches as I mentioned above. All the same FTP and same Image. I don't get a response from the FTP when trying to connect with this particular switch. I do however have a successful ping to the FTP server from this switch. I have deleted all configurations on the units before setting up mine for the transfer. I also have the confreg set to ignore any configurations just in case i miss any. I can add the arp later today. 

I tried the first suggested response with the entire command all at once and same outcome. 

Here is the output

Switch#copy ftp://bob:password@$
Destination filename [cat4500-entservicesk9-mz.150-2.SG11.bin]?
Accessing ftp://bob:password@
%Error opening ftp://bob:password@ (Protocol error)

Switch#sho arp
Protocol Address Age (min) Hardware Addr Type Interface
Internet 0 f8b1.56b0.67dd ARPA Vlan1
Internet 0 48f8.b3a0.e107 ARPA Vlan1
Internet - 0022.557b.0a7f ARPA Vlan1 



There is a bug (  regarding ftp and 4500 - not sure if you are using the affected release. I would have thought this bug would result in "Incorrect Login/Password" rather than "protocol error" so it may not be what you are experiencing.



Thanks for the additional information. It is helpful to know that other switches have used this server and this image file without problems. Is it possible that the user ID for FTP and/or the password for FTP are different on this switch?


The arp information does show that there is successful communication between the switch and the server at layer 2. And the fact that the switch is successful in ping to the server confirms IP connectivity and eliminates that as a potential problem.


Perhaps debug for ftp might provide some insight?






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