How to increase the TFTP File Transfer Rate on a Nexus 9000 Switch

[oslopez]

Hi,

I'm trying to update NXOS on several Nexus switches located in remote locations from a local TFTP server. Problem is, even though the TFTP server and switches are located in the same location, it takes a long time to download the 1GB file in the switches. I know that some Catalyst switches can adjust the TFTP block size to a bigger number than 512 to speed up TFTP file transfers.

However, I haven't had any luck finding a command that does just that.  The ip tftp command only allows to configure source interface for TFTP client.

Does anybody know how to adjust this parameter on Nexus Switches?

Any clue would be appreciated.   

[Georg Pauwen · Accepted solution]

Hello,

I think in NX-OS all you can change is the TFTP source interface. That said, TFTP is sort of outdated, better use SCP or SFTP (enable the feature first if you want to use these on your Nexus 900...-->feature scp-server/feature sftp-server

[dgaunt]

Use the use-kstack syntax at the end of your SCP or SFTP copy command to increase throughput. 

See Documentation for details: Cisco Nexus 9000 Series NX-OS Programmability Guide, Release 9.3(x) - Bash [Cisco Nexus 9000 Series Switches] - Cisco

[Joseph W. Doherty]

As the other posters have already described, using a TCP based protocol is likely to be "faster" (due to TCP windowing) than using a UDP based protocol.

Somethings to also keep in mind Cisco device flash can be a bottleneck, as also perhaps the device's CPU (also CoPP [Nexus?] can be another performance limiter).

[D Hart]

Try "ip tcp mss 10000"

[Joseph W. Doherty]

"Try "ip tcp mss 10000""

BTW, won't help tftp.

[D Hart]

I tried to delete it after I posted but couldn’t find that option.

[Elliot Dierksen]

This doesn't appear to be available on NX-OS, but it helped a LOT on IOS-XE

ip tftp blocksize 8192