Description

This article explains the meaning of the following syslog message:

tftpd[1842]: Timeout #1422 on DATA block 21

Symptoms

There can be instances where, during tftp read operation, a specific data block is dropped during transfer between RE and the PFE. The RE on not seeing the data block starts a retry timer in which it expects to see the data again. Once this retry timer crosses the max timeout value (5 seconds), the following syslog messages appear, indicating a timeout has occurred for that specific data block: 

tftpd[1842]: Timeout #1422 on DATA block 21
1842 is the process ID for tftp daemon. The log is printed for timeout instance # 1422 for the data block # 21

Solution

These syslog messages do not impact service and can be masked using KB9382 - How to prevent certain syslog messages from being written to the log file [juniper.net] .

In situations where syslog messages are seen indicating the tftp read operation was aborted, that would be a reason of concern, as aborting would generally occur due to a read error or  an error in the packet.

The following PR has been filed for this issue and to implement the long-term fix: In the fixed Junos version, an upper check limit is imposed to stop the packet transmission to go into an infinite loop, thus causing this syslog message from overflowing the message file.