I have two EC2 instances that were created from the same AMI, which was created from the Amazon Linux AMI. These are running mysql in a master-slave configuration. The security group ("db") is configured to allow port 22 from instances running under security group "web".
So, I ssh into one of the web instances, and then ssh or scp to the database instances. This has been working fine for a while.
Today, however, I can no longer scp to one of the instances (the master). I can ssh into it just fine, and both scp and ssh work fine to the slave instance.
Running scp with -vv produces almost idential output, up to the debug2: line below, which is the last output when connecting to the master.
debug2: exec request accepted on channel 0 Sending file modes: C0775 77 <filename>
Any idea what is going on? I've tried re-starting the instance, and that didn't make any difference.
/var/log/secure: Jan 10 19:02:59 <host> sshd: Accepted publickey for <user> from xx.xxx.xxx.xxx port 33285 ssh2 Jan 10 19:02:59 <host> sshd: pam_unix(sshd:session): session opened for user <user> by (uid=0)
There were about 20 lines or so added to /var/log/audit/audit.log, all ending in