Secure download of RHEL ISO installation images

You will probably download the RHEL ISO image from within the Red Hat Customer Portal and therefore use an encrypted HTTPS connection (download URL is https://access.cdn.redhat.com/…). The SHA-256 checksums for the ISO images are on the download page.

Red Hat also provides a page with all GPG keys they use for signing their software packages. In Customer Portal, go to “Security” -> “Product Signing (GPG) Keys)” (https://www.redhat.com/security/team/key/)

There are download links for the public keys (https://www.redhat.com/…). The keys are also available on the keyserver pgp.mit.edu . So you can use the following command to import the main Red Hat key into your GPG keyring:

# gpg --recv-keys fd431d51
# gpg --fingerprint -k fd431d51

Compare the fingerprint of the Red Hat public key with the fingerprint on the Customer Portal website. You cannot use the GPG key for verifying the ISO files, but it is useful for e.g. verifying RPM package updates that you can download directly from Red Hat websites and that are not installed the usual way via an official yum repository.

 

iSCSI connection states in Open-iSCSI

This is the iSCSI connection state if the underlying network interface changes from “UP BROADCAST RUNNING MULTICAST” to “UP BROADCAST MULTICAST”.

Log entries showing that the network interface has no longer the state “RUNNING”:

Jul 3 14:17:31 host kernel: [974138.571169] bnx2 0000:08:05.0 eth2: NIC Copper Link is Down
Jul 3 23:05:05 host kernel: [1005760.957474] sd 10:0:0:0: rejecting I/O to offline device
... previous message repeats many times ...

Checking iSCSI connection state:

# iscsiadm -m session -P1
...
iSCSI Connection State: TRANSPORT WAIT
iSCSI Session State: FREE
Internal iscsid Session State: REOPEN

Log entry once the network interface state is back to “RUNNING”:

Jul 4 06:56:31 host kernel: [1034019.191222] bnx2 0000:08:05.0 eth2: NIC Copper Link is Up, 1000 Mbps full duplex

Checking iSCSI connection state again:

# iscsiadm -m session -P1
...
iSCSI Connection State: LOGGED IN
iSCSI Session State: LOGGED_IN
Internal iscsid Session State: NO CHANGE

The output of “iscsiadm -m session -P1” can be used for monitoring the iSCSI connection e.g. in a simple Nagios or Icinga Perl script.