Troubleshooting

Unusual Network Activity

SSH-Related Problems

Switch access refused to a client. Even though you have placed the client’s public key in a text file and copied the file (using the copy tftp pub-key- file command) into the switch, the switch refuses to allow the client to have access. If the source SSH client is an SSHv2 application, the public key may be in the PEM format, which the switch (SSHv1) does not interpret. Check the SSH client application for a utility that can convert the PEM-formatted key into an ASCII-formatted key.

Executing IP SSH does not enable SSH on the switch. The switch does not have a host key. Verify by executing show ip host-public-key. If you see the message

ssh cannot be enabled until a host key is configured (use 'crypto' command).

then you need to generate an SSH key pair for the switch. To do so, execute crypto key generate.(Refer to “2. Generating the Switch’s Public and Private Key Pair” in the SSH chapter of the Access Security Guide for your switch.)

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