连接堡垒服务器时必须开启代理转发:

You have to enable agent forwarding when connecting to the bastion server:

my $ssh = Net::SSH::Perl->new(
    $host,
    debug          => 1,
    identity_files => \@KEYFILE,
    options        => [
        'ForwardAgent yes',
    ],
);

有关其他 ssh Perl 模块及其优缺点，请参阅 Net::OpenSSH 与 Net::SSH:: 模块.

For other ssh Perl modules and their pros and cons see Net::OpenSSH vs Net::SSH:: modules.