My Oracle Support Banner

How To Debug Slow/Hung ssh Connection (Doc ID 2546864.1)

Last updated on MAY 29, 2020

Applies to:

Linux OS - Version Oracle Linux 5.1 to Oracle Linux 7.6 [Release OL5U1 to OL7U6]
Linux x86
Linux x86-64

Symptoms

Typical issues for ssh connections:

Cause

To view full details, sign in with your My Oracle Support account.

Don't have a My Oracle Support account? Click to get started!


In this Document
Symptoms
Cause
Solution
 Basic debug
 example commands
 Example cases
 Lots of network devices along the ssh connection
 Firewall in the middle of traffic
 DNS issues
 MTU miss-match along the connection path
 sshd_config file issues
 Hosts allow/deny files are set wrongly
 3rd party PAM modules used
 Performance issues on host or limits reached
 NIC tuning missing
 Remote logging server is not responding
References

My Oracle Support provides customers with access to over a million knowledge articles and a vibrant support community of peers and Oracle experts.