updating redhat server from CentOS repository
 

We have a number of servers that are behind firewalls and I haven't been able to figure out how to get the official redhat updates for my internal repository that I want to use to patch these servers, so instead I want to mirror CentOS updates and use those to patch. My understanding is that the CentOS RPMs are supposed to be virtually identical to Redhat RPMs. Can anyone cofirm or deny this? What horrors could ensue if I do this? I've already discovered that if I allow the CentOS kernel to update my existing Redhat kernel, my test box thinks that it is a CentOS box. But everything seems to be working properly.

The only way to get access to RH's repos (binaries) is to pay the subscription price.

Centos builds their rpms from RH's source. They do have to remove all the proprietary parts (mostly logos) first.

CentOS is binary compatible with RHEL, so you should have no problems from using CentOS repositories. They are built from the same source code, using the same compiler options.

However, as lazlow points out, some of the Red Hat branding and logos may disappear, which includes things like the contents of /etc/release, as packages are updated.

thanks.

We have paid for subscriptions for these servers, but our support contract is through HP rather than redhat. HP linux support can't tell me how I can pull the updates down to my repository and I don't have access to directly ask redhat how to do it.

Look at
yum downloadonly

note that yum goes out to the internet, so you need to allow outbound to RH. Its not a server listening at your end.
There are also 2 official extra RH methods : RH Proxy server, Satellite server. You can check out all the info at the RH website as if you have paid for RH, you have an RHN login avail, even if you normally get support from HP.
Also, if HP can't explain it to you, you can try asking RH, they usually try to help in cases like this. Good PR.