tftp transfer painfully slow

Question

I am using HPA's tftp server for PXE boot. When I try downloading an image from my tftp server using curl, the transfer rate is less than 3 MB/s, even on my 1Gb network.

curl -o initrd.gz tftp://192.168.0.4:69/boot/debian/initrd.gz

Is this an inherent limitation of the tftp protocol, or can this be configured?

Same problem here,hpux and solaris tftp are really fast Linux tftp is ultraslow(slackware) — elbarna, Dec 06 '14 at 23:54

score 7 · Accepted Answer · edited Mar 29 '14 at 09:08

7

Try to increase the maximum block size on the server (e.g. --blocksize 1468).
Check with server in debug mode, see if there are retransmits.
Check if you really have Gb connection end-to-end.
Test on a different client node.
Check if there is some other problem not related to tftp - try iperf, tcpdump, ethtool ...

edited Mar 29 '14 at 09:08

Raphael Ahrens

9,701
5
37
52

answered Mar 29 '14 at 07:30

Zrin

341
2
7

2

setting `--blocksize 1468` on the server alone did not help. I had to specify the block size on the client as well, i.e. `curl --tftp-blksize 1468`. Then I get around `6.5 MB/s`. This still does not seem very impressive. With ftp, I get over `100 MB/s` on the same machines. – Martin Vegter Mar 29 '14 at 11:29

score 2 · Answer 2 · answered Feb 04 '22 at 15:22

TFTP is inherently slow, because it waits for an ACK from the other end after transmitting every block. If your client supports it, you may get more performance by using a TFTP server which supports the RFC 7440 extension. The upstream version of HPA's tftp server does not, but apparrently there are some patches to add it.

tftp transfer painfully slow

2 Answers2